]> git.proxmox.com Git - ceph.git/blobdiff - ceph/src/civetweb/src/third_party/duktape-1.5.2/src-separate/duk_bi_json.c
import quincy beta 17.1.0
[ceph.git] / ceph / src / civetweb / src / third_party / duktape-1.5.2 / src-separate / duk_bi_json.c
diff --git a/ceph/src/civetweb/src/third_party/duktape-1.5.2/src-separate/duk_bi_json.c b/ceph/src/civetweb/src/third_party/duktape-1.5.2/src-separate/duk_bi_json.c
deleted file mode 100644 (file)
index d05ccd9..0000000
+++ /dev/null
@@ -1,3143 +0,0 @@
-/*
- *  JSON built-ins.
- *
- *  See doc/json.rst.
- *
- *  Codepoints are handled as duk_uint_fast32_t to ensure that the full
- *  unsigned 32-bit range is supported.  This matters to e.g. JX.
- *
- *  Input parsing doesn't do an explicit end-of-input check at all.  This is
- *  safe: input string data is always NUL-terminated (0x00) and valid JSON
- *  inputs never contain plain NUL characters, so that as long as syntax checks
- *  are correct, we'll never read past the NUL.  This approach reduces code size
- *  and improves parsing performance, but it's critical that syntax checks are
- *  indeed correct!
- */
-
-#include "duk_internal.h"
-
-/*
- *  Local defines and forward declarations.
- */
-
-#define DUK__JSON_DECSTR_BUFSIZE 128
-#define DUK__JSON_DECSTR_CHUNKSIZE 64
-#define DUK__JSON_ENCSTR_CHUNKSIZE 64
-#define DUK__JSON_STRINGIFY_BUFSIZE 128
-#define DUK__JSON_MAX_ESC_LEN 10  /* '\Udeadbeef' */
-
-DUK_LOCAL_DECL void duk__dec_syntax_error(duk_json_dec_ctx *js_ctx);
-DUK_LOCAL_DECL void duk__dec_eat_white(duk_json_dec_ctx *js_ctx);
-DUK_LOCAL_DECL duk_uint8_t duk__dec_peek(duk_json_dec_ctx *js_ctx);
-DUK_LOCAL_DECL duk_uint8_t duk__dec_get(duk_json_dec_ctx *js_ctx);
-DUK_LOCAL_DECL duk_uint8_t duk__dec_get_nonwhite(duk_json_dec_ctx *js_ctx);
-DUK_LOCAL_DECL duk_uint_fast32_t duk__dec_decode_hex_escape(duk_json_dec_ctx *js_ctx, duk_small_uint_t n);
-DUK_LOCAL_DECL void duk__dec_req_stridx(duk_json_dec_ctx *js_ctx, duk_small_uint_t stridx);
-DUK_LOCAL_DECL void duk__dec_string(duk_json_dec_ctx *js_ctx);
-#ifdef DUK_USE_JX
-DUK_LOCAL_DECL void duk__dec_plain_string(duk_json_dec_ctx *js_ctx);
-DUK_LOCAL_DECL void duk__dec_pointer(duk_json_dec_ctx *js_ctx);
-DUK_LOCAL_DECL void duk__dec_buffer(duk_json_dec_ctx *js_ctx);
-#endif
-DUK_LOCAL_DECL void duk__dec_number(duk_json_dec_ctx *js_ctx);
-DUK_LOCAL_DECL void duk__dec_objarr_entry(duk_json_dec_ctx *js_ctx);
-DUK_LOCAL_DECL void duk__dec_objarr_exit(duk_json_dec_ctx *js_ctx);
-DUK_LOCAL_DECL void duk__dec_object(duk_json_dec_ctx *js_ctx);
-DUK_LOCAL_DECL void duk__dec_array(duk_json_dec_ctx *js_ctx);
-DUK_LOCAL_DECL void duk__dec_value(duk_json_dec_ctx *js_ctx);
-DUK_LOCAL_DECL void duk__dec_reviver_walk(duk_json_dec_ctx *js_ctx);
-
-DUK_LOCAL_DECL void duk__emit_1(duk_json_enc_ctx *js_ctx, duk_uint_fast8_t ch);
-DUK_LOCAL_DECL void duk__emit_2(duk_json_enc_ctx *js_ctx, duk_uint_fast8_t ch1, duk_uint_fast8_t ch2);
-DUK_LOCAL_DECL void duk__unemit_1(duk_json_enc_ctx *js_ctx);
-DUK_LOCAL_DECL void duk__emit_hstring(duk_json_enc_ctx *js_ctx, duk_hstring *h);
-#if defined(DUK_USE_FASTINT)
-DUK_LOCAL_DECL void duk__emit_cstring(duk_json_enc_ctx *js_ctx, const char *p);
-#endif
-DUK_LOCAL_DECL void duk__emit_stridx(duk_json_enc_ctx *js_ctx, duk_small_uint_t stridx);
-DUK_LOCAL_DECL duk_uint8_t *duk__emit_esc_auto_fast(duk_json_enc_ctx *js_ctx, duk_uint_fast32_t cp, duk_uint8_t *q);
-DUK_LOCAL_DECL void duk__enc_key_autoquote(duk_json_enc_ctx *js_ctx, duk_hstring *k);
-DUK_LOCAL_DECL void duk__enc_quote_string(duk_json_enc_ctx *js_ctx, duk_hstring *h_str);
-DUK_LOCAL_DECL void duk__enc_objarr_entry(duk_json_enc_ctx *js_ctx, duk_idx_t *entry_top);
-DUK_LOCAL_DECL void duk__enc_objarr_exit(duk_json_enc_ctx *js_ctx, duk_idx_t *entry_top);
-DUK_LOCAL_DECL void duk__enc_object(duk_json_enc_ctx *js_ctx);
-DUK_LOCAL_DECL void duk__enc_array(duk_json_enc_ctx *js_ctx);
-DUK_LOCAL_DECL duk_bool_t duk__enc_value(duk_json_enc_ctx *js_ctx, duk_idx_t idx_holder);
-DUK_LOCAL_DECL duk_bool_t duk__enc_allow_into_proplist(duk_tval *tv);
-DUK_LOCAL_DECL void duk__enc_double(duk_json_enc_ctx *js_ctx);
-#if defined(DUK_USE_FASTINT)
-DUK_LOCAL_DECL void duk__enc_fastint_tval(duk_json_enc_ctx *js_ctx, duk_tval *tv);
-#endif
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-DUK_LOCAL_DECL void duk__enc_buffer(duk_json_enc_ctx *js_ctx, duk_hbuffer *h);
-DUK_LOCAL_DECL void duk__enc_pointer(duk_json_enc_ctx *js_ctx, void *ptr);
-DUK_LOCAL_DECL void duk__enc_bufferobject(duk_json_enc_ctx *js_ctx, duk_hbufferobject *h_bufobj);
-#endif
-DUK_LOCAL_DECL void duk__enc_newline_indent(duk_json_enc_ctx *js_ctx, duk_int_t depth);
-
-/*
- *  Helper tables
- */
-
-#if defined(DUK_USE_JSON_QUOTESTRING_FASTPATH)
-DUK_LOCAL const duk_uint8_t duk__json_quotestr_lookup[256] = {
-       /* 0x00 ... 0x7f: as is
-        * 0x80: escape generically
-        * 0x81: slow path
-        * 0xa0 ... 0xff: backslash + one char
-        */
-
-       0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0xe2, 0xf4, 0xee, 0x80, 0xe6, 0xf2, 0x80, 0x80,
-       0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
-       0x20, 0x21, 0xa2, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
-       0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
-       0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
-       0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0xdc, 0x5d, 0x5e, 0x5f,
-       0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
-       0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x81,
-       0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81,
-       0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81,
-       0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81,
-       0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81,
-       0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81,
-       0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81,
-       0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81,
-       0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81
-};
-#else  /* DUK_USE_JSON_QUOTESTRING_FASTPATH */
-DUK_LOCAL const duk_uint8_t duk__json_quotestr_esc[14] = {
-       DUK_ASC_NUL, DUK_ASC_NUL, DUK_ASC_NUL, DUK_ASC_NUL,
-       DUK_ASC_NUL, DUK_ASC_NUL, DUK_ASC_NUL, DUK_ASC_NUL,
-       DUK_ASC_LC_B, DUK_ASC_LC_T, DUK_ASC_LC_N, DUK_ASC_NUL,
-       DUK_ASC_LC_F, DUK_ASC_LC_R
-};
-#endif  /* DUK_USE_JSON_QUOTESTRING_FASTPATH */
-
-#if defined(DUK_USE_JSON_DECSTRING_FASTPATH)
-DUK_LOCAL const duk_uint8_t duk__json_decstr_lookup[256] = {
-       /* 0x00: slow path
-        * other: as is
-        */
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x20, 0x21, 0x00, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
-       0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
-       0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
-       0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x00, 0x5d, 0x5e, 0x5f,
-       0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
-       0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
-       0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
-       0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
-       0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
-       0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
-       0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
-       0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
-       0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
-       0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff
-};
-#endif  /* DUK_USE_JSON_DECSTRING_FASTPATH */
-
-#if defined(DUK_USE_JSON_EATWHITE_FASTPATH)
-DUK_LOCAL const duk_uint8_t duk__json_eatwhite_lookup[256] = {
-       /* 0x00: finish (non-white)
-        * 0x01: continue
-        */
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x00, 0x00, 0x01, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
-};
-#endif  /* DUK_USE_JSON_EATWHITE_FASTPATH */
-
-#if defined(DUK_USE_JSON_DECNUMBER_FASTPATH)
-DUK_LOCAL const duk_uint8_t duk__json_decnumber_lookup[256] = {
-       /* 0x00: finish (not part of number)
-        * 0x01: continue
-        */
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x01, 0x00,
-       0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
-};
-#endif  /* DUK_USE_JSON_DECNUMBER_FASTPATH */
-
-/*
- *  Parsing implementation.
- *
- *  JSON lexer is now separate from duk_lexer.c because there are numerous
- *  small differences making it difficult to share the lexer.
- *
- *  The parser here works with raw bytes directly; this works because all
- *  JSON delimiters are ASCII characters.  Invalid xUTF-8 encoded values
- *  inside strings will be passed on without normalization; this is not a
- *  compliance concern because compliant inputs will always be valid
- *  CESU-8 encodings.
- */
-
-DUK_LOCAL void duk__dec_syntax_error(duk_json_dec_ctx *js_ctx) {
-       /* Shared handler to minimize parser size.  Cause will be
-        * hidden, unfortunately, but we'll have an offset which
-        * is often quite enough.
-        */
-       DUK_ERROR_FMT1(js_ctx->thr, DUK_ERR_SYNTAX_ERROR, DUK_STR_FMT_INVALID_JSON,
-                      (long) (js_ctx->p - js_ctx->p_start));
-}
-
-DUK_LOCAL void duk__dec_eat_white(duk_json_dec_ctx *js_ctx) {
-       const duk_uint8_t *p;
-       duk_uint8_t t;
-
-       p = js_ctx->p;
-       for (;;) {
-               DUK_ASSERT(p <= js_ctx->p_end);
-               t = *p;
-
-#if defined(DUK_USE_JSON_EATWHITE_FASTPATH)
-               /* This fast path is pretty marginal in practice.
-                * XXX: candidate for removal.
-                */
-               DUK_ASSERT(duk__json_eatwhite_lookup[0x00] == 0x00);  /* end-of-input breaks */
-               if (duk__json_eatwhite_lookup[t] == 0) {
-                       break;
-               }
-#else  /* DUK_USE_JSON_EATWHITE_FASTPATH */
-               if (!(t == 0x20 || t == 0x0a || t == 0x0d || t == 0x09)) {
-                       /* NUL also comes here.  Comparison order matters, 0x20
-                        * is most common whitespace.
-                        */
-                       break;
-               }
-#endif  /* DUK_USE_JSON_EATWHITE_FASTPATH */
-               p++;
-       }
-       js_ctx->p = p;
-}
-
-DUK_LOCAL duk_uint8_t duk__dec_peek(duk_json_dec_ctx *js_ctx) {
-       DUK_ASSERT(js_ctx->p <= js_ctx->p_end);
-       return *js_ctx->p;
-}
-
-DUK_LOCAL duk_uint8_t duk__dec_get(duk_json_dec_ctx *js_ctx) {
-       DUK_ASSERT(js_ctx->p <= js_ctx->p_end);
-       return *js_ctx->p++;
-}
-
-DUK_LOCAL duk_uint8_t duk__dec_get_nonwhite(duk_json_dec_ctx *js_ctx) {
-       duk__dec_eat_white(js_ctx);
-       return duk__dec_get(js_ctx);
-}
-
-/* For JX, expressing the whole unsigned 32-bit range matters. */
-DUK_LOCAL duk_uint_fast32_t duk__dec_decode_hex_escape(duk_json_dec_ctx *js_ctx, duk_small_uint_t n) {
-       duk_small_uint_t i;
-       duk_uint_fast32_t res = 0;
-       duk_uint8_t x;
-       duk_small_int_t t;
-
-       for (i = 0; i < n; i++) {
-               /* XXX: share helper from lexer; duk_lexer.c / hexval(). */
-
-               x = duk__dec_get(js_ctx);
-               DUK_DDD(DUK_DDDPRINT("decode_hex_escape: i=%ld, n=%ld, res=%ld, x=%ld",
-                                    (long) i, (long) n, (long) res, (long) x));
-
-               /* x == 0x00 (EOF) causes syntax_error */
-               DUK_ASSERT(duk_hex_dectab[0] == -1);
-               t = duk_hex_dectab[x & 0xff];
-               if (DUK_LIKELY(t >= 0)) {
-                       res = (res * 16) + t;
-               } else {
-                       /* catches EOF and invalid digits */
-                       goto syntax_error;
-               }
-       }
-
-       DUK_DDD(DUK_DDDPRINT("final hex decoded value: %ld", (long) res));
-       return res;
-
- syntax_error:
-       duk__dec_syntax_error(js_ctx);
-       DUK_UNREACHABLE();
-       return 0;
-}
-
-DUK_LOCAL void duk__dec_req_stridx(duk_json_dec_ctx *js_ctx, duk_small_uint_t stridx) {
-       duk_hstring *h;
-       const duk_uint8_t *p;
-       duk_uint8_t x, y;
-
-       /* First character has already been eaten and checked by the caller.
-        * We can scan until a NUL in stridx string because no built-in strings
-        * have internal NULs.
-        */
-
-       DUK_ASSERT_DISABLE(stridx >= 0);  /* unsigned */
-       DUK_ASSERT(stridx < DUK_HEAP_NUM_STRINGS);
-       h = DUK_HTHREAD_GET_STRING(js_ctx->thr, stridx);
-       DUK_ASSERT(h != NULL);
-
-       p = (const duk_uint8_t *) DUK_HSTRING_GET_DATA(h) + 1;
-       DUK_ASSERT(*(js_ctx->p - 1) == *(p - 1));  /* first character has been matched */
-
-       for (;;) {
-               x = *p;
-               if (x == 0) {
-                       break;
-               }
-               y = duk__dec_get(js_ctx);
-               if (x != y) {
-                       /* Catches EOF of JSON input. */
-                       goto syntax_error;
-               }
-               p++;
-       }
-
-       return;
-
- syntax_error:
-       duk__dec_syntax_error(js_ctx);
-       DUK_UNREACHABLE();
-}
-
-DUK_LOCAL duk_small_int_t duk__dec_string_escape(duk_json_dec_ctx *js_ctx, duk_uint8_t **ext_p) {
-       duk_uint_fast32_t cp;
-
-       /* EOF (-1) will be cast to an unsigned value first
-        * and then re-cast for the switch.  In any case, it
-        * will match the default case (syntax error).
-        */
-       cp = (duk_uint_fast32_t) duk__dec_get(js_ctx);
-       switch ((int) cp) {
-       case DUK_ASC_BACKSLASH: break;
-       case DUK_ASC_DOUBLEQUOTE: break;
-       case DUK_ASC_SLASH: break;
-       case DUK_ASC_LC_T: cp = 0x09; break;
-       case DUK_ASC_LC_N: cp = 0x0a; break;
-       case DUK_ASC_LC_R: cp = 0x0d; break;
-       case DUK_ASC_LC_F: cp = 0x0c; break;
-       case DUK_ASC_LC_B: cp = 0x08; break;
-       case DUK_ASC_LC_U: {
-               cp = duk__dec_decode_hex_escape(js_ctx, 4);
-               break;
-       }
-#ifdef DUK_USE_JX
-       case DUK_ASC_UC_U: {
-               if (js_ctx->flag_ext_custom) {
-                       cp = duk__dec_decode_hex_escape(js_ctx, 8);
-               } else {
-                       return 1;  /* syntax error */
-               }
-               break;
-       }
-       case DUK_ASC_LC_X: {
-               if (js_ctx->flag_ext_custom) {
-                       cp = duk__dec_decode_hex_escape(js_ctx, 2);
-               } else {
-                       return 1;  /* syntax error */
-               }
-               break;
-       }
-#endif  /* DUK_USE_JX */
-       default:
-               /* catches EOF (0x00) */
-               return 1;  /* syntax error */
-       }
-
-       DUK_RAW_WRITE_XUTF8(*ext_p, cp);
-
-       return 0;
-}
-
-DUK_LOCAL void duk__dec_string(duk_json_dec_ctx *js_ctx) {
-       duk_hthread *thr = js_ctx->thr;
-       duk_context *ctx = (duk_context *) thr;
-       duk_bufwriter_ctx bw_alloc;
-       duk_bufwriter_ctx *bw;
-       duk_uint8_t *q;
-
-       /* '"' was eaten by caller */
-
-       /* Note that we currently parse -bytes-, not codepoints.
-        * All non-ASCII extended UTF-8 will encode to bytes >= 0x80,
-        * so they'll simply pass through (valid UTF-8 or not).
-        */
-
-       bw = &bw_alloc;
-       DUK_BW_INIT_PUSHBUF(js_ctx->thr, bw, DUK__JSON_DECSTR_BUFSIZE);
-       q = DUK_BW_GET_PTR(js_ctx->thr, bw);
-
-#if defined(DUK_USE_JSON_DECSTRING_FASTPATH)
-       for (;;) {
-               duk_small_uint_t safe;
-               duk_uint8_t b, x;
-               const duk_uint8_t *p;
-
-               /* Select a safe loop count where no output checks are
-                * needed assuming we won't encounter escapes.  Input
-                * bound checks are not necessary as a NUL (guaranteed)
-                * will cause a SyntaxError before we read out of bounds.
-                */
-
-               safe = DUK__JSON_DECSTR_CHUNKSIZE;
-
-               /* Ensure space for 1:1 output plus one escape. */
-               q = DUK_BW_ENSURE_RAW(js_ctx->thr, bw, safe + DUK_UNICODE_MAX_XUTF8_LENGTH, q);
-
-               p = js_ctx->p;  /* temp copy, write back for next loop */
-               for (;;) {
-                       if (safe == 0) {
-                               js_ctx->p = p;
-                               break;
-                       }
-                       safe--;
-
-                       /* End of input (NUL) goes through slow path and causes SyntaxError. */
-                       DUK_ASSERT(duk__json_decstr_lookup[0] == 0x00);
-
-                       b = *p++;
-                       x = (duk_small_int_t) duk__json_decstr_lookup[b];
-                       if (DUK_LIKELY(x != 0)) {
-                               /* Fast path, decode as is. */
-                               *q++ = b;
-                       } else if (b == DUK_ASC_DOUBLEQUOTE) {
-                               js_ctx->p = p;
-                               goto found_quote;
-                       } else if (b == DUK_ASC_BACKSLASH) {
-                               /* We've ensured space for one escaped input; then
-                                * bail out and recheck (this makes escape handling
-                                * quite slow but it's uncommon).
-                                */
-                               js_ctx->p = p;
-                               if (duk__dec_string_escape(js_ctx, &q) != 0) {
-                                       goto syntax_error;
-                               }
-                               break;
-                       } else {
-                               js_ctx->p = p;
-                               goto syntax_error;
-                       }
-               }
-       }
- found_quote:
-#else  /* DUK_USE_JSON_DECSTRING_FASTPATH */
-       for (;;) {
-               duk_uint8_t x;
-
-               q = DUK_BW_ENSURE_RAW(js_ctx->thr, bw, DUK_UNICODE_MAX_XUTF8_LENGTH, q);
-
-               x = duk__dec_get(js_ctx);
-
-               if (x == DUK_ASC_DOUBLEQUOTE) {
-                       break;
-               } else if (x == DUK_ASC_BACKSLASH) {
-                       if (duk__dec_string_escape(js_ctx, &q) != 0) {
-                               goto syntax_error;
-                       }
-               } else if (x < 0x20) {
-                       /* catches EOF (NUL) */
-                       goto syntax_error;
-               } else {
-                       *q++ = (duk_uint8_t) x;
-               }
-       }
-#endif  /* DUK_USE_JSON_DECSTRING_FASTPATH */
-
-       DUK_BW_SETPTR_AND_COMPACT(js_ctx->thr, bw, q);
-       duk_to_string(ctx, -1);
-
-       /* [ ... str ] */
-
-       return;
-
- syntax_error:
-       duk__dec_syntax_error(js_ctx);
-       DUK_UNREACHABLE();
-}
-
-#ifdef DUK_USE_JX
-/* Decode a plain string consisting entirely of identifier characters.
- * Used to parse plain keys (e.g. "foo: 123").
- */
-DUK_LOCAL void duk__dec_plain_string(duk_json_dec_ctx *js_ctx) {
-       duk_hthread *thr = js_ctx->thr;
-       duk_context *ctx = (duk_context *) thr;
-       const duk_uint8_t *p;
-       duk_small_int_t x;
-
-       /* Caller has already eaten the first char so backtrack one byte. */
-
-       js_ctx->p--;  /* safe */
-       p = js_ctx->p;
-
-       /* Here again we parse bytes, and non-ASCII UTF-8 will cause end of
-        * parsing (which is correct except if there are non-shortest encodings).
-        * There is also no need to check explicitly for end of input buffer as
-        * the input is NUL padded and NUL will exit the parsing loop.
-        *
-        * Because no unescaping takes place, we can just scan to the end of the
-        * plain string and intern from the input buffer.
-        */
-
-       for (;;) {
-               x = *p;
-
-               /* There is no need to check the first character specially here
-                * (i.e. reject digits): the caller only accepts valid initial
-                * characters and won't call us if the first character is a digit.
-                * This also ensures that the plain string won't be empty.
-                */
-
-               if (!duk_unicode_is_identifier_part((duk_codepoint_t) x)) {
-                       break;
-               }
-               p++;
-       }
-
-       duk_push_lstring(ctx, (const char *) js_ctx->p, (duk_size_t) (p - js_ctx->p));
-       js_ctx->p = p;
-
-       /* [ ... str ] */
-}
-#endif  /* DUK_USE_JX */
-
-#ifdef DUK_USE_JX
-DUK_LOCAL void duk__dec_pointer(duk_json_dec_ctx *js_ctx) {
-       duk_hthread *thr = js_ctx->thr;
-       duk_context *ctx = (duk_context *) thr;
-       const duk_uint8_t *p;
-       duk_small_int_t x;
-       void *voidptr;
-
-       /* Caller has already eaten the first character ('(') which we don't need. */
-
-       p = js_ctx->p;
-
-       for (;;) {
-               x = *p;
-
-               /* Assume that the native representation never contains a closing
-                * parenthesis.
-                */
-
-               if (x == DUK_ASC_RPAREN) {
-                       break;
-               } else if (x <= 0) {
-                       /* NUL term or -1 (EOF), NUL check would suffice */
-                       goto syntax_error;
-               }
-               p++;
-       }
-
-       /* There is no need to NUL delimit the sscanf() call: trailing garbage is
-        * ignored and there is always a NUL terminator which will force an error
-        * if no error is encountered before it.  It's possible that the scan
-        * would scan further than between [js_ctx->p,p[ though and we'd advance
-        * by less than the scanned value.
-        *
-        * Because pointers are platform specific, a failure to scan a pointer
-        * results in a null pointer which is a better placeholder than a missing
-        * value or an error.
-        */
-
-       voidptr = NULL;
-       (void) DUK_SSCANF((const char *) js_ctx->p, DUK_STR_FMT_PTR, &voidptr);
-       duk_push_pointer(ctx, voidptr);
-       js_ctx->p = p + 1;  /* skip ')' */
-
-       /* [ ... ptr ] */
-
-       return;
-
- syntax_error:
-       duk__dec_syntax_error(js_ctx);
-       DUK_UNREACHABLE();
-}
-#endif  /* DUK_USE_JX */
-
-#ifdef DUK_USE_JX
-DUK_LOCAL void duk__dec_buffer(duk_json_dec_ctx *js_ctx) {
-       duk_hthread *thr = js_ctx->thr;
-       duk_context *ctx = (duk_context *) thr;
-       const duk_uint8_t *p;
-       duk_uint8_t *buf;
-       duk_size_t src_len;
-       duk_small_int_t x;
-
-       /* Caller has already eaten the first character ('|') which we don't need. */
-
-       p = js_ctx->p;
-
-       /* XXX: Would be nice to share the fast path loop from duk_hex_decode()
-        * and avoid creating a temporary buffer.  However, there are some
-        * differences which prevent trivial sharing:
-        *
-        *   - Pipe char detection
-        *   - EOF detection
-        *   - Unknown length of input and output
-        *
-        * The best approach here would be a bufwriter and a reasonaly sized
-        * safe inner loop (e.g. 64 output bytes at a time).
-        */
-
-       for (;;) {
-               x = *p;
-
-               /* This loop intentionally does not ensure characters are valid
-                * ([0-9a-fA-F]) because the hex decode call below will do that.
-                */
-               if (x == DUK_ASC_PIPE) {
-                       break;
-               } else if (x <= 0) {
-                       /* NUL term or -1 (EOF), NUL check would suffice */
-                       goto syntax_error;
-               }
-               p++;
-       }
-
-       src_len = (duk_size_t) (p - js_ctx->p);
-       buf = (duk_uint8_t *) duk_push_fixed_buffer(ctx, src_len);
-       DUK_ASSERT(buf != NULL);
-       DUK_MEMCPY((void *) buf, (const void *) js_ctx->p, src_len);
-       duk_hex_decode(ctx, -1);
-
-       js_ctx->p = p + 1;  /* skip '|' */
-
-       /* [ ... buf ] */
-
-       return;
-
- syntax_error:
-       duk__dec_syntax_error(js_ctx);
-       DUK_UNREACHABLE();
-}
-#endif  /* DUK_USE_JX */
-
-/* Parse a number, other than NaN or +/- Infinity */
-DUK_LOCAL void duk__dec_number(duk_json_dec_ctx *js_ctx) {
-       duk_context *ctx = (duk_context *) js_ctx->thr;
-       const duk_uint8_t *p_start;
-       const duk_uint8_t *p;
-       duk_uint8_t x;
-       duk_small_uint_t s2n_flags;
-
-       DUK_DDD(DUK_DDDPRINT("parse_number"));
-
-       p_start = js_ctx->p;
-
-       /* First pass parse is very lenient (e.g. allows '1.2.3') and extracts a
-        * string for strict number parsing.
-        */
-
-       p = js_ctx->p;
-       for (;;) {
-               x = *p;
-
-               DUK_DDD(DUK_DDDPRINT("parse_number: p_start=%p, p=%p, p_end=%p, x=%ld",
-                                    (const void *) p_start, (const void *) p,
-                                    (const void *) js_ctx->p_end, (long) x));
-
-#if defined(DUK_USE_JSON_DECNUMBER_FASTPATH)
-               /* This fast path is pretty marginal in practice.
-                * XXX: candidate for removal.
-                */
-               DUK_ASSERT(duk__json_decnumber_lookup[0x00] == 0x00);  /* end-of-input breaks */
-               if (duk__json_decnumber_lookup[x] == 0) {
-                       break;
-               }
-#else  /* DUK_USE_JSON_DECNUMBER_FASTPATH */
-               if (!((x >= DUK_ASC_0 && x <= DUK_ASC_9) ||
-                     (x == DUK_ASC_PERIOD || x == DUK_ASC_LC_E ||
-                      x == DUK_ASC_UC_E || x == DUK_ASC_MINUS || x == DUK_ASC_PLUS))) {
-                       /* Plus sign must be accepted for positive exponents
-                        * (e.g. '1.5e+2').  This clause catches NULs.
-                        */
-                       break;
-               }
-#endif  /* DUK_USE_JSON_DECNUMBER_FASTPATH */
-               p++;  /* safe, because matched (NUL causes a break) */
-       }
-       js_ctx->p = p;
-
-       DUK_ASSERT(js_ctx->p > p_start);
-       duk_push_lstring(ctx, (const char *) p_start, (duk_size_t) (p - p_start));
-
-       s2n_flags = DUK_S2N_FLAG_ALLOW_EXP |
-                   DUK_S2N_FLAG_ALLOW_MINUS |  /* but don't allow leading plus */
-                   DUK_S2N_FLAG_ALLOW_FRAC;
-
-       DUK_DDD(DUK_DDDPRINT("parse_number: string before parsing: %!T",
-                            (duk_tval *) duk_get_tval(ctx, -1)));
-       duk_numconv_parse(ctx, 10 /*radix*/, s2n_flags);
-       if (duk_is_nan(ctx, -1)) {
-               duk__dec_syntax_error(js_ctx);
-       }
-       DUK_ASSERT(duk_is_number(ctx, -1));
-       DUK_DDD(DUK_DDDPRINT("parse_number: final number: %!T",
-                            (duk_tval *) duk_get_tval(ctx, -1)));
-
-       /* [ ... num ] */
-}
-
-DUK_LOCAL void duk__dec_objarr_entry(duk_json_dec_ctx *js_ctx) {
-       duk_context *ctx = (duk_context *) js_ctx->thr;
-       duk_require_stack(ctx, DUK_JSON_DEC_REQSTACK);
-
-       /* c recursion check */
-
-       DUK_ASSERT(js_ctx->recursion_depth >= 0);
-       DUK_ASSERT(js_ctx->recursion_depth <= js_ctx->recursion_limit);
-       if (js_ctx->recursion_depth >= js_ctx->recursion_limit) {
-               DUK_ERROR_RANGE((duk_hthread *) ctx, DUK_STR_JSONDEC_RECLIMIT);
-       }
-       js_ctx->recursion_depth++;
-}
-
-DUK_LOCAL void duk__dec_objarr_exit(duk_json_dec_ctx *js_ctx) {
-       /* c recursion check */
-
-       DUK_ASSERT(js_ctx->recursion_depth > 0);
-       DUK_ASSERT(js_ctx->recursion_depth <= js_ctx->recursion_limit);
-       js_ctx->recursion_depth--;
-}
-
-DUK_LOCAL void duk__dec_object(duk_json_dec_ctx *js_ctx) {
-       duk_context *ctx = (duk_context *) js_ctx->thr;
-       duk_int_t key_count;  /* XXX: a "first" flag would suffice */
-       duk_uint8_t x;
-
-       DUK_DDD(DUK_DDDPRINT("parse_object"));
-
-       duk__dec_objarr_entry(js_ctx);
-
-       duk_push_object(ctx);
-
-       /* Initial '{' has been checked and eaten by caller. */
-
-       key_count = 0;
-       for (;;) {
-               x = duk__dec_get_nonwhite(js_ctx);
-
-               DUK_DDD(DUK_DDDPRINT("parse_object: obj=%!T, x=%ld, key_count=%ld",
-                                    (duk_tval *) duk_get_tval(ctx, -1),
-                                    (long) x, (long) key_count));
-
-               /* handle comma and closing brace */
-
-               if (x == DUK_ASC_COMMA && key_count > 0) {
-                       /* accept comma, expect new value */
-                       x = duk__dec_get_nonwhite(js_ctx);
-               } else if (x == DUK_ASC_RCURLY) {
-                       /* eat closing brace */
-                       break;
-               } else if (key_count == 0) {
-                       /* accept anything, expect first value (EOF will be
-                        * caught by key parsing below.
-                        */
-                       ;
-               } else {
-                       /* catches EOF (NUL) and initial comma */
-                       goto syntax_error;
-               }
-
-               /* parse key and value */
-
-               if (x == DUK_ASC_DOUBLEQUOTE) {
-                       duk__dec_string(js_ctx);
-#ifdef DUK_USE_JX
-               } else if (js_ctx->flag_ext_custom &&
-                          duk_unicode_is_identifier_start((duk_codepoint_t) x)) {
-                       duk__dec_plain_string(js_ctx);
-#endif
-               } else {
-                       goto syntax_error;
-               }
-
-               /* [ ... obj key ] */
-
-               x = duk__dec_get_nonwhite(js_ctx);
-               if (x != DUK_ASC_COLON) {
-                       goto syntax_error;
-               }
-
-               duk__dec_value(js_ctx);
-
-               /* [ ... obj key val ] */
-
-               duk_xdef_prop_wec(ctx, -3);
-
-               /* [ ... obj ] */
-
-               key_count++;
-       }
-
-       /* [ ... obj ] */
-
-       DUK_DDD(DUK_DDDPRINT("parse_object: final object is %!T",
-                            (duk_tval *) duk_get_tval(ctx, -1)));
-
-       duk__dec_objarr_exit(js_ctx);
-       return;
-
- syntax_error:
-       duk__dec_syntax_error(js_ctx);
-       DUK_UNREACHABLE();
-}
-
-DUK_LOCAL void duk__dec_array(duk_json_dec_ctx *js_ctx) {
-       duk_context *ctx = (duk_context *) js_ctx->thr;
-       duk_uarridx_t arr_idx;
-       duk_uint8_t x;
-
-       DUK_DDD(DUK_DDDPRINT("parse_array"));
-
-       duk__dec_objarr_entry(js_ctx);
-
-       duk_push_array(ctx);
-
-       /* Initial '[' has been checked and eaten by caller. */
-
-       arr_idx = 0;
-       for (;;) {
-               x = duk__dec_get_nonwhite(js_ctx);
-
-               DUK_DDD(DUK_DDDPRINT("parse_array: arr=%!T, x=%ld, arr_idx=%ld",
-                                    (duk_tval *) duk_get_tval(ctx, -1),
-                                    (long) x, (long) arr_idx));
-
-               /* handle comma and closing bracket */
-
-               if ((x == DUK_ASC_COMMA) && (arr_idx != 0)) {
-                       /* accept comma, expect new value */
-                       ;
-               } else if (x == DUK_ASC_RBRACKET) {
-                       /* eat closing bracket */
-                       break;
-               } else if (arr_idx == 0) {
-                       /* accept anything, expect first value (EOF will be
-                        * caught by duk__dec_value() below.
-                        */
-                       js_ctx->p--;  /* backtrack (safe) */
-               } else {
-                       /* catches EOF (NUL) and initial comma */
-                       goto syntax_error;
-               }
-
-               /* parse value */
-
-               duk__dec_value(js_ctx);
-
-               /* [ ... arr val ] */
-
-               duk_xdef_prop_index_wec(ctx, -2, arr_idx);
-               arr_idx++;
-       }
-
-       /* Must set 'length' explicitly when using duk_xdef_prop_xxx() to
-        * set the values.
-        */
-
-       duk_set_length(ctx, -1, arr_idx);
-
-       /* [ ... arr ] */
-
-       DUK_DDD(DUK_DDDPRINT("parse_array: final array is %!T",
-                            (duk_tval *) duk_get_tval(ctx, -1)));
-
-       duk__dec_objarr_exit(js_ctx);
-       return;
-
- syntax_error:
-       duk__dec_syntax_error(js_ctx);
-       DUK_UNREACHABLE();
-}
-
-DUK_LOCAL void duk__dec_value(duk_json_dec_ctx *js_ctx) {
-       duk_context *ctx = (duk_context *) js_ctx->thr;
-       duk_uint8_t x;
-
-       x = duk__dec_get_nonwhite(js_ctx);
-
-       DUK_DDD(DUK_DDDPRINT("parse_value: initial x=%ld", (long) x));
-
-       /* Note: duk__dec_req_stridx() backtracks one char */
-
-       if (x == DUK_ASC_DOUBLEQUOTE) {
-               duk__dec_string(js_ctx);
-       } else if ((x >= DUK_ASC_0 && x <= DUK_ASC_9) || (x == DUK_ASC_MINUS)) {
-#ifdef DUK_USE_JX
-               if (js_ctx->flag_ext_custom && x == DUK_ASC_MINUS && duk__dec_peek(js_ctx) == DUK_ASC_UC_I) {
-                       duk__dec_req_stridx(js_ctx, DUK_STRIDX_MINUS_INFINITY);  /* "-Infinity", '-' has been eaten */
-                       duk_push_number(ctx, -DUK_DOUBLE_INFINITY);
-               } else {
-#else
-               {  /* unconditional block */
-#endif
-                       /* We already ate 'x', so backup one byte. */
-                       js_ctx->p--;  /* safe */
-                       duk__dec_number(js_ctx);
-               }
-       } else if (x == DUK_ASC_LC_T) {
-               duk__dec_req_stridx(js_ctx, DUK_STRIDX_TRUE);
-               duk_push_true(ctx);
-       } else if (x == DUK_ASC_LC_F) {
-               duk__dec_req_stridx(js_ctx, DUK_STRIDX_FALSE);
-               duk_push_false(ctx);
-       } else if (x == DUK_ASC_LC_N) {
-               duk__dec_req_stridx(js_ctx, DUK_STRIDX_LC_NULL);
-               duk_push_null(ctx);
-#ifdef DUK_USE_JX
-       } else if (js_ctx->flag_ext_custom && x == DUK_ASC_LC_U) {
-               duk__dec_req_stridx(js_ctx, DUK_STRIDX_LC_UNDEFINED);
-               duk_push_undefined(ctx);
-       } else if (js_ctx->flag_ext_custom && x == DUK_ASC_UC_N) {
-               duk__dec_req_stridx(js_ctx, DUK_STRIDX_NAN);
-               duk_push_nan(ctx);
-       } else if (js_ctx->flag_ext_custom && x == DUK_ASC_UC_I) {
-               duk__dec_req_stridx(js_ctx, DUK_STRIDX_INFINITY);
-               duk_push_number(ctx, DUK_DOUBLE_INFINITY);
-       } else if (js_ctx->flag_ext_custom && x == DUK_ASC_LPAREN) {
-               duk__dec_pointer(js_ctx);
-       } else if (js_ctx->flag_ext_custom && x == DUK_ASC_PIPE) {
-               duk__dec_buffer(js_ctx);
-#endif
-       } else if (x == DUK_ASC_LCURLY) {
-               duk__dec_object(js_ctx);
-       } else if (x == DUK_ASC_LBRACKET) {
-               duk__dec_array(js_ctx);
-       } else {
-               /* catches EOF (NUL) */
-               goto syntax_error;
-       }
-
-       duk__dec_eat_white(js_ctx);
-
-       /* [ ... val ] */
-       return;
-
- syntax_error:
-       duk__dec_syntax_error(js_ctx);
-       DUK_UNREACHABLE();
-}
-
-/* Recursive value reviver, implements the Walk() algorithm.  No C recursion
- * check is done here because the initial parsing step will already ensure
- * there is a reasonable limit on C recursion depth and hence object depth.
- */
-DUK_LOCAL void duk__dec_reviver_walk(duk_json_dec_ctx *js_ctx) {
-       duk_context *ctx = (duk_context *) js_ctx->thr;
-       duk_hobject *h;
-       duk_uarridx_t i, arr_len;
-
-       DUK_DDD(DUK_DDDPRINT("walk: top=%ld, holder=%!T, name=%!T",
-                            (long) duk_get_top(ctx),
-                            (duk_tval *) duk_get_tval(ctx, -2),
-                            (duk_tval *) duk_get_tval(ctx, -1)));
-
-       duk_dup_top(ctx);
-       duk_get_prop(ctx, -3);  /* -> [ ... holder name val ] */
-
-       h = duk_get_hobject(ctx, -1);
-       if (h != NULL) {
-               if (DUK_HOBJECT_GET_CLASS_NUMBER(h) == DUK_HOBJECT_CLASS_ARRAY) {
-                       arr_len = (duk_uarridx_t) duk_get_length(ctx, -1);
-                       for (i = 0; i < arr_len; i++) {
-                               /* [ ... holder name val ] */
-
-                               DUK_DDD(DUK_DDDPRINT("walk: array, top=%ld, i=%ld, arr_len=%ld, holder=%!T, name=%!T, val=%!T",
-                                                    (long) duk_get_top(ctx), (long) i, (long) arr_len,
-                                                    (duk_tval *) duk_get_tval(ctx, -3), (duk_tval *) duk_get_tval(ctx, -2),
-                                                    (duk_tval *) duk_get_tval(ctx, -1)));
-
-                               /* XXX: push_uint_string / push_u32_string */
-                               duk_dup_top(ctx);
-                               duk_push_uint(ctx, (duk_uint_t) i);
-                               duk_to_string(ctx, -1);  /* -> [ ... holder name val val ToString(i) ] */
-                               duk__dec_reviver_walk(js_ctx);  /* -> [ ... holder name val new_elem ] */
-
-                               if (duk_is_undefined(ctx, -1)) {
-                                       duk_pop(ctx);
-                                       duk_del_prop_index(ctx, -1, i);
-                               } else {
-                                       /* XXX: duk_xdef_prop_index_wec() would be more appropriate
-                                        * here but it currently makes some assumptions that might
-                                        * not hold (e.g. that previous property is not an accessor).
-                                        */
-                                       duk_put_prop_index(ctx, -2, i);
-                               }
-                       }
-               } else {
-                       /* [ ... holder name val ] */
-                       duk_enum(ctx, -1, DUK_ENUM_OWN_PROPERTIES_ONLY /*flags*/);
-                       while (duk_next(ctx, -1 /*enum_index*/, 0 /*get_value*/)) {
-                               DUK_DDD(DUK_DDDPRINT("walk: object, top=%ld, holder=%!T, name=%!T, val=%!T, enum=%!iT, obj_key=%!T",
-                                                    (long) duk_get_top(ctx), (duk_tval *) duk_get_tval(ctx, -5),
-                                                    (duk_tval *) duk_get_tval(ctx, -4), (duk_tval *) duk_get_tval(ctx, -3),
-                                                    (duk_tval *) duk_get_tval(ctx, -2), (duk_tval *) duk_get_tval(ctx, -1)));
-
-                               /* [ ... holder name val enum obj_key ] */
-                               duk_dup(ctx, -3);
-                               duk_dup(ctx, -2);
-
-                               /* [ ... holder name val enum obj_key val obj_key ] */
-                               duk__dec_reviver_walk(js_ctx);
-
-                               /* [ ... holder name val enum obj_key new_elem ] */
-                               if (duk_is_undefined(ctx, -1)) {
-                                       duk_pop(ctx);
-                                       duk_del_prop(ctx, -3);
-                               } else {
-                                       /* XXX: duk_xdef_prop_index_wec() would be more appropriate
-                                        * here but it currently makes some assumptions that might
-                                        * not hold (e.g. that previous property is not an accessor).
-                                        *
-                                        * Using duk_put_prop() works incorrectly with '__proto__'
-                                        * if the own property with that name has been deleted.  This
-                                        * does not happen normally, but a clever reviver can trigger
-                                        * that, see complex reviver case in: test-bug-json-parse-__proto__.js.
-                                        */
-                                       duk_put_prop(ctx, -4);
-                               }
-                       }
-                       duk_pop(ctx);  /* pop enum */
-               }
-       }
-
-       /* [ ... holder name val ] */
-
-       duk_dup(ctx, js_ctx->idx_reviver);
-       duk_insert(ctx, -4);  /* -> [ ... reviver holder name val ] */
-       duk_call_method(ctx, 2);  /* -> [ ... res ] */
-
-       DUK_DDD(DUK_DDDPRINT("walk: top=%ld, result=%!T",
-                            (long) duk_get_top(ctx), (duk_tval *) duk_get_tval(ctx, -1)));
-}
-
-/*
- *  Stringify implementation.
- */
-
-#define DUK__EMIT_1(js_ctx,ch)          duk__emit_1((js_ctx), (duk_uint_fast8_t) (ch))
-#define DUK__EMIT_2(js_ctx,ch1,ch2)     duk__emit_2((js_ctx), (duk_uint_fast8_t) (ch1), (duk_uint_fast8_t) (ch2))
-#define DUK__EMIT_HSTR(js_ctx,h)        duk__emit_hstring((js_ctx), (h))
-#if defined(DUK_USE_FASTINT) || defined(DUK_USE_JX) || defined(DUK_USE_JC)
-#define DUK__EMIT_CSTR(js_ctx,p)        duk__emit_cstring((js_ctx), (p))
-#endif
-#define DUK__EMIT_STRIDX(js_ctx,i)      duk__emit_stridx((js_ctx), (i))
-#define DUK__UNEMIT_1(js_ctx)           duk__unemit_1((js_ctx))
-
-DUK_LOCAL void duk__emit_1(duk_json_enc_ctx *js_ctx, duk_uint_fast8_t ch) {
-       DUK_BW_WRITE_ENSURE_U8(js_ctx->thr, &js_ctx->bw, ch);
-}
-
-DUK_LOCAL void duk__emit_2(duk_json_enc_ctx *js_ctx, duk_uint_fast8_t ch1, duk_uint_fast8_t ch2) {
-       DUK_BW_WRITE_ENSURE_U8_2(js_ctx->thr, &js_ctx->bw, ch1, ch2);
-}
-
-DUK_LOCAL void duk__emit_hstring(duk_json_enc_ctx *js_ctx, duk_hstring *h) {
-       DUK_BW_WRITE_ENSURE_HSTRING(js_ctx->thr, &js_ctx->bw, h);
-}
-
-#if defined(DUK_USE_FASTINT) || defined(DUK_USE_JX) || defined(DUK_USE_JC)
-DUK_LOCAL void duk__emit_cstring(duk_json_enc_ctx *js_ctx, const char *str) {
-       DUK_BW_WRITE_ENSURE_CSTRING(js_ctx->thr, &js_ctx->bw, str);
-}
-#endif
-
-DUK_LOCAL void duk__emit_stridx(duk_json_enc_ctx *js_ctx, duk_small_uint_t stridx) {
-       duk_hstring *h;
-
-       DUK_ASSERT_DISABLE(stridx >= 0);  /* unsigned */
-       DUK_ASSERT(stridx < DUK_HEAP_NUM_STRINGS);
-       h = DUK_HTHREAD_GET_STRING(js_ctx->thr, stridx);
-       DUK_ASSERT(h != NULL);
-
-       DUK_BW_WRITE_ENSURE_HSTRING(js_ctx->thr, &js_ctx->bw, h);
-}
-
-DUK_LOCAL void duk__unemit_1(duk_json_enc_ctx *js_ctx) {
-       DUK_ASSERT(DUK_BW_GET_SIZE(js_ctx->thr, &js_ctx->bw) >= 1);
-       DUK_BW_ADD_PTR(js_ctx->thr, &js_ctx->bw, -1);
-}
-
-#define DUK__MKESC(nybbles,esc1,esc2)  \
-       (((duk_uint_fast32_t) (nybbles)) << 16) | \
-       (((duk_uint_fast32_t) (esc1)) << 8) | \
-       ((duk_uint_fast32_t) (esc2))
-
-DUK_LOCAL duk_uint8_t *duk__emit_esc_auto_fast(duk_json_enc_ctx *js_ctx, duk_uint_fast32_t cp, duk_uint8_t *q) {
-       duk_uint_fast32_t tmp;
-       duk_small_uint_t dig;
-
-       DUK_UNREF(js_ctx);
-
-       /* Caller ensures space for at least DUK__JSON_MAX_ESC_LEN. */
-
-       /* Select appropriate escape format automatically, and set 'tmp' to a
-        * value encoding both the escape format character and the nybble count:
-        *
-        *   (nybble_count << 16) | (escape_char1) | (escape_char2)
-        */
-
-#ifdef DUK_USE_JX
-       if (DUK_LIKELY(cp < 0x100UL)) {
-               if (DUK_UNLIKELY(js_ctx->flag_ext_custom)) {
-                       tmp = DUK__MKESC(2, DUK_ASC_BACKSLASH, DUK_ASC_LC_X);
-               } else {
-                       tmp = DUK__MKESC(4, DUK_ASC_BACKSLASH, DUK_ASC_LC_U);
-               }
-       } else
-#endif
-       if (DUK_LIKELY(cp < 0x10000UL)) {
-               tmp = DUK__MKESC(4, DUK_ASC_BACKSLASH, DUK_ASC_LC_U);
-       } else {
-#ifdef DUK_USE_JX
-               if (DUK_LIKELY(js_ctx->flag_ext_custom)) {
-                       tmp = DUK__MKESC(8, DUK_ASC_BACKSLASH, DUK_ASC_UC_U);
-               } else
-#endif
-               {
-                       /* In compatible mode and standard JSON mode, output
-                        * something useful for non-BMP characters.  This won't
-                        * roundtrip but will still be more or less readable and
-                        * more useful than an error.
-                        */
-                       tmp = DUK__MKESC(8, DUK_ASC_UC_U, DUK_ASC_PLUS);
-               }
-       }
-
-       *q++ = (duk_uint8_t) ((tmp >> 8) & 0xff);
-       *q++ = (duk_uint8_t) (tmp & 0xff);
-
-       tmp = tmp >> 16;
-       while (tmp > 0) {
-               tmp--;
-               dig = (duk_small_uint_t) ((cp >> (4 * tmp)) & 0x0f);
-               *q++ = duk_lc_digits[dig];
-       }
-
-       return q;
-}
-
-DUK_LOCAL void duk__enc_key_autoquote(duk_json_enc_ctx *js_ctx, duk_hstring *k) {
-       const duk_int8_t *p, *p_start, *p_end;  /* Note: intentionally signed. */
-       duk_size_t k_len;
-       duk_codepoint_t cp;
-
-       DUK_ASSERT(k != NULL);
-
-       /* Accept ASCII strings which conform to identifier requirements
-        * as being emitted without key quotes.  Since we only accept ASCII
-        * there's no need for actual decoding: 'p' is intentionally signed
-        * so that bytes >= 0x80 extend to negative values and are rejected
-        * as invalid identifier codepoints.
-        */
-
-       if (js_ctx->flag_avoid_key_quotes) {
-               k_len = DUK_HSTRING_GET_BYTELEN(k);
-               p_start = (const duk_int8_t *) DUK_HSTRING_GET_DATA(k);
-               p_end = p_start + k_len;
-               p = p_start;
-
-               if (p == p_end) {
-                       /* Zero length string is not accepted without quotes */
-                       goto quote_normally;
-               }
-               cp = (duk_codepoint_t) (*p++);
-               if (DUK_UNLIKELY(!duk_unicode_is_identifier_start(cp))) {
-                       goto quote_normally;
-               }
-               while (p < p_end) {
-                       cp = (duk_codepoint_t) (*p++);
-                       if (DUK_UNLIKELY(!duk_unicode_is_identifier_part(cp))) {
-                               goto quote_normally;
-                       }
-               }
-
-               /* This seems faster than emitting bytes one at a time and
-                * then potentially rewinding.
-                */
-               DUK__EMIT_HSTR(js_ctx, k);
-               return;
-       }
-
- quote_normally:
-       duk__enc_quote_string(js_ctx, k);
-}
-
-/* The Quote(value) operation: quote a string.
- *
- * Stack policy: [ ] -> [ ].
- */
-
-DUK_LOCAL void duk__enc_quote_string(duk_json_enc_ctx *js_ctx, duk_hstring *h_str) {
-       duk_hthread *thr = js_ctx->thr;
-       const duk_uint8_t *p, *p_start, *p_end, *p_now, *p_tmp;
-       duk_uint8_t *q;
-       duk_ucodepoint_t cp;  /* typed for duk_unicode_decode_xutf8() */
-
-       DUK_DDD(DUK_DDDPRINT("duk__enc_quote_string: h_str=%!O", (duk_heaphdr *) h_str));
-
-       DUK_ASSERT(h_str != NULL);
-       p_start = DUK_HSTRING_GET_DATA(h_str);
-       p_end = p_start + DUK_HSTRING_GET_BYTELEN(h_str);
-       p = p_start;
-
-       DUK__EMIT_1(js_ctx, DUK_ASC_DOUBLEQUOTE);
-
-       /* Encode string in small chunks, estimating the maximum expansion so that
-        * there's no need to ensure space while processing the chunk.
-        */
-
-       while (p < p_end) {
-               duk_size_t left, now, space;
-
-               left = (duk_size_t) (p_end - p);
-               now = (left > DUK__JSON_ENCSTR_CHUNKSIZE ?
-                      DUK__JSON_ENCSTR_CHUNKSIZE : left);
-
-               /* Maximum expansion per input byte is 6:
-                *   - invalid UTF-8 byte causes "\uXXXX" to be emitted (6/1 = 6).
-                *   - 2-byte UTF-8 encodes as "\uXXXX" (6/2 = 3).
-                *   - 4-byte UTF-8 encodes as "\Uxxxxxxxx" (10/4 = 2.5).
-                */
-               space = now * 6;
-               q = DUK_BW_ENSURE_GETPTR(thr, &js_ctx->bw, space);
-
-               p_now = p + now;
-
-               while (p < p_now) {
-#if defined(DUK_USE_JSON_QUOTESTRING_FASTPATH)
-                       duk_uint8_t b;
-
-                       b = duk__json_quotestr_lookup[*p++];
-                       if (DUK_LIKELY(b < 0x80)) {
-                               /* Most input bytes go through here. */
-                               *q++ = b;
-                       } else if (b >= 0xa0) {
-                               *q++ = DUK_ASC_BACKSLASH;
-                               *q++ = (duk_uint8_t) (b - 0x80);
-                       } else if (b == 0x80) {
-                               cp = (duk_ucodepoint_t) (*(p - 1));
-                               q = duk__emit_esc_auto_fast(js_ctx, cp, q);
-                       } else if (b == 0x7f && js_ctx->flag_ascii_only) {
-                               /* 0x7F is special */
-                               DUK_ASSERT(b == 0x81);
-                               cp = (duk_ucodepoint_t) 0x7f;
-                               q = duk__emit_esc_auto_fast(js_ctx, cp, q);
-                       } else {
-                               DUK_ASSERT(b == 0x81);
-                               p--;
-
-                               /* slow path is shared */
-#else  /* DUK_USE_JSON_QUOTESTRING_FASTPATH */
-                       cp = *p;
-
-                       if (DUK_LIKELY(cp <= 0x7f)) {
-                               /* ascii fast path: avoid decoding utf-8 */
-                               p++;
-                               if (cp == 0x22 || cp == 0x5c) {
-                                       /* double quote or backslash */
-                                       *q++ = DUK_ASC_BACKSLASH;
-                                       *q++ = (duk_uint8_t) cp;
-                               } else if (cp < 0x20) {
-                                       duk_uint_fast8_t esc_char;
-
-                                       /* This approach is a bit shorter than a straight
-                                        * if-else-ladder and also a bit faster.
-                                        */
-                                       if (cp < (sizeof(duk__json_quotestr_esc) / sizeof(duk_uint8_t)) &&
-                                           (esc_char = duk__json_quotestr_esc[cp]) != 0) {
-                                               *q++ = DUK_ASC_BACKSLASH;
-                                               *q++ = (duk_uint8_t) esc_char;
-                                       } else {
-                                               q = duk__emit_esc_auto_fast(js_ctx, cp, q);
-                                       }
-                               } else if (cp == 0x7f && js_ctx->flag_ascii_only) {
-                                       q = duk__emit_esc_auto_fast(js_ctx, cp, q);
-                               } else {
-                                       /* any other printable -> as is */
-                                       *q++ = (duk_uint8_t) cp;
-                               }
-                       } else {
-                               /* slow path is shared */
-#endif  /* DUK_USE_JSON_QUOTESTRING_FASTPATH */
-
-                               /* slow path decode */
-
-                               /* If XUTF-8 decoding fails, treat the offending byte as a codepoint directly
-                                * and go forward one byte.  This is of course very lossy, but allows some kind
-                                * of output to be produced even for internal strings which don't conform to
-                                * XUTF-8.  All standard Ecmascript strings are always CESU-8, so this behavior
-                                * does not violate the Ecmascript specification.  The behavior is applied to
-                                * all modes, including Ecmascript standard JSON.  Because the current XUTF-8
-                                * decoding is not very strict, this behavior only really affects initial bytes
-                                * and truncated codepoints.
-                                *
-                                * Another alternative would be to scan forwards to start of next codepoint
-                                * (or end of input) and emit just one replacement codepoint.
-                                */
-
-                               p_tmp = p;
-                               if (!duk_unicode_decode_xutf8(thr, &p, p_start, p_end, &cp)) {
-                                       /* Decode failed. */
-                                       cp = *p_tmp;
-                                       p = p_tmp + 1;
-                               }
-
-#ifdef DUK_USE_NONSTD_JSON_ESC_U2028_U2029
-                               if (js_ctx->flag_ascii_only || cp == 0x2028 || cp == 0x2029) {
-#else
-                               if (js_ctx->flag_ascii_only) {
-#endif
-                                       q = duk__emit_esc_auto_fast(js_ctx, cp, q);
-                               } else {
-                                       /* as is */
-                                       DUK_RAW_WRITE_XUTF8(q, cp);
-                               }
-                       }
-               }
-
-               DUK_BW_SET_PTR(thr, &js_ctx->bw, q);
-       }
-
-       DUK__EMIT_1(js_ctx, DUK_ASC_DOUBLEQUOTE);
-}
-
-/* Encode a double (checked by caller) from stack top.  Stack top may be
- * replaced by serialized string but is not popped (caller does that).
- */
-DUK_LOCAL void duk__enc_double(duk_json_enc_ctx *js_ctx) {
-       duk_hthread *thr;
-       duk_context *ctx;
-       duk_tval *tv;
-       duk_double_t d;
-       duk_small_int_t c;
-       duk_small_int_t s;
-       duk_small_uint_t stridx;
-       duk_small_uint_t n2s_flags;
-       duk_hstring *h_str;
-
-       DUK_ASSERT(js_ctx != NULL);
-       thr = js_ctx->thr;
-       DUK_ASSERT(thr != NULL);
-       ctx = (duk_context *) thr;
-
-       /* Caller must ensure 'tv' is indeed a double and not a fastint! */
-       tv = DUK_GET_TVAL_NEGIDX(ctx, -1);
-       DUK_ASSERT(DUK_TVAL_IS_DOUBLE(tv));
-       d = DUK_TVAL_GET_DOUBLE(tv);
-
-       c = (duk_small_int_t) DUK_FPCLASSIFY(d);
-       s = (duk_small_int_t) DUK_SIGNBIT(d);
-       DUK_UNREF(s);
-
-       if (DUK_LIKELY(!(c == DUK_FP_INFINITE || c == DUK_FP_NAN))) {
-               DUK_ASSERT(DUK_ISFINITE(d));
-
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-               /* Negative zero needs special handling in JX/JC because
-                * it would otherwise serialize to '0', not '-0'.
-                */
-               if (DUK_UNLIKELY(c == DUK_FP_ZERO && s != 0 &&
-                                (js_ctx->flag_ext_custom_or_compatible))) {
-                       duk_push_hstring_stridx(ctx, DUK_STRIDX_MINUS_ZERO);  /* '-0' */
-               } else
-#endif  /* DUK_USE_JX || DUK_USE_JC */
-               {
-                       n2s_flags = 0;
-                       /* [ ... number ] -> [ ... string ] */
-                       duk_numconv_stringify(ctx, 10 /*radix*/, 0 /*digits*/, n2s_flags);
-               }
-               h_str = duk_to_hstring(ctx, -1);
-               DUK_ASSERT(h_str != NULL);
-               DUK__EMIT_HSTR(js_ctx, h_str);
-               return;
-       }
-
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-       if (!(js_ctx->flags & (DUK_JSON_FLAG_EXT_CUSTOM |
-                              DUK_JSON_FLAG_EXT_COMPATIBLE))) {
-               stridx = DUK_STRIDX_LC_NULL;
-       } else if (c == DUK_FP_NAN) {
-               stridx = js_ctx->stridx_custom_nan;
-       } else if (s == 0) {
-               stridx = js_ctx->stridx_custom_posinf;
-       } else {
-               stridx = js_ctx->stridx_custom_neginf;
-       }
-#else
-       stridx = DUK_STRIDX_LC_NULL;
-#endif
-       DUK__EMIT_STRIDX(js_ctx, stridx);
-}
-
-#if defined(DUK_USE_FASTINT)
-/* Encode a fastint from duk_tval ptr, no value stack effects. */
-DUK_LOCAL void duk__enc_fastint_tval(duk_json_enc_ctx *js_ctx, duk_tval *tv) {
-       duk_int64_t v;
-
-       /* Fastint range is signed 48-bit so longest value is -2^47 = -140737488355328
-        * (16 chars long), longest signed 64-bit value is -2^63 = -9223372036854775808
-        * (20 chars long).  Alloc space for 64-bit range to be safe.
-        */
-       duk_uint8_t buf[20 + 1];
-
-       /* Caller must ensure 'tv' is indeed a fastint! */
-       DUK_ASSERT(DUK_TVAL_IS_FASTINT(tv));
-       v = DUK_TVAL_GET_FASTINT(tv);
-
-       /* XXX: There are no format strings in duk_config.h yet, could add
-        * one for formatting duk_int64_t.  For now, assumes "%lld" and that
-        * "long long" type exists.  Could also rely on C99 directly but that
-        * won't work for older MSVC.
-        */
-       DUK_SPRINTF((char *) buf, "%lld", (long long) v);
-       DUK__EMIT_CSTR(js_ctx, (const char *) buf);
-}
-#endif
-
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-#if defined(DUK_USE_HEX_FASTPATH)
-DUK_LOCAL duk_uint8_t *duk__enc_buffer_data_hex(const duk_uint8_t *src, duk_size_t src_len, duk_uint8_t *dst) {
-       duk_uint8_t *q;
-       duk_uint16_t *q16;
-       duk_small_uint_t x;
-       duk_size_t i, len_safe;
-#if !defined(DUK_USE_UNALIGNED_ACCESSES_POSSIBLE)
-       duk_bool_t shift_dst;
-#endif
-
-       /* Unlike in duk_hex_encode() 'dst' is not necessarily aligned by 2.
-        * For platforms where unaligned accesses are not allowed, shift 'dst'
-        * ahead by 1 byte to get alignment and then DUK_MEMMOVE() the result
-        * in place.  The faster encoding loop makes up the difference.
-        * There's always space for one extra byte because a terminator always
-        * follows the hex data and that's been accounted for by the caller.
-        */
-
-#if defined(DUK_USE_UNALIGNED_ACCESSES_POSSIBLE)
-       q16 = (duk_uint16_t *) (void *) dst;
-#else
-       shift_dst = (duk_bool_t) (((duk_size_t) dst) & 0x01U);
-       if (shift_dst) {
-               DUK_DD(DUK_DDPRINT("unaligned accesses not possible, dst not aligned -> step to dst + 1"));
-               q16 = (duk_uint16_t *) (void *) (dst + 1);
-       } else {
-               DUK_DD(DUK_DDPRINT("unaligned accesses not possible, dst is aligned"));
-               q16 = (duk_uint16_t *) (void *) dst;
-       }
-       DUK_ASSERT((((duk_size_t) q16) & 0x01U) == 0);
-#endif
-
-       len_safe = src_len & ~0x03U;
-       for (i = 0; i < len_safe; i += 4) {
-               q16[0] = duk_hex_enctab[src[i]];
-               q16[1] = duk_hex_enctab[src[i + 1]];
-               q16[2] = duk_hex_enctab[src[i + 2]];
-               q16[3] = duk_hex_enctab[src[i + 3]];
-               q16 += 4;
-       }
-       q = (duk_uint8_t *) q16;
-
-#if !defined(DUK_USE_UNALIGNED_ACCESSES_POSSIBLE)
-       if (shift_dst) {
-               q--;
-               DUK_MEMMOVE((void *) dst, (const void *) (dst + 1), 2 * len_safe);
-               DUK_ASSERT(dst + 2 * len_safe == q);
-       }
-#endif
-
-       for (; i < src_len; i++) {
-               x = src[i];
-               *q++ = duk_lc_digits[x >> 4];
-               *q++ = duk_lc_digits[x & 0x0f];
-       }
-
-       return q;
-}
-#else  /* DUK_USE_HEX_FASTPATH */
-DUK_LOCAL duk_uint8_t *duk__enc_buffer_data_hex(const duk_uint8_t *src, duk_size_t src_len, duk_uint8_t *dst) {
-       const duk_uint8_t *p;
-       const duk_uint8_t *p_end;
-       duk_uint8_t *q;
-       duk_small_uint_t x;
-
-       p = src;
-       p_end = src + src_len;
-       q = dst;
-       while (p != p_end) {
-               x = *p++;
-               *q++ = duk_lc_digits[x >> 4];
-               *q++ = duk_lc_digits[x & 0x0f];
-       }
-
-       return q;
-}
-#endif  /* DUK_USE_HEX_FASTPATH */
-
-DUK_LOCAL void duk__enc_buffer_data(duk_json_enc_ctx *js_ctx, duk_uint8_t *buf_data, duk_size_t buf_len) {
-       duk_hthread *thr;
-       duk_uint8_t *q;
-       duk_size_t space;
-
-       thr = js_ctx->thr;
-
-       DUK_ASSERT(js_ctx->flag_ext_custom || js_ctx->flag_ext_compatible);  /* caller checks */
-       DUK_ASSERT(js_ctx->flag_ext_custom_or_compatible);
-
-       /* Buffer values are encoded in (lowercase) hex to make the
-        * binary data readable.  Base64 or similar would be more
-        * compact but less readable, and the point of JX/JC
-        * variants is to be as useful to a programmer as possible.
-        */
-
-       /* The #ifdef clutter here needs to handle the three cases:
-        * (1) JX+JC, (2) JX only, (3) JC only.
-        */
-
-       /* Note: space must cater for both JX and JC. */
-       space = 9 + buf_len * 2 + 2;
-       DUK_ASSERT(DUK_HBUFFER_MAX_BYTELEN <= 0x7ffffffeUL);
-       DUK_ASSERT((space - 2) / 2 >= buf_len);  /* overflow not possible, buffer limits */
-       q = DUK_BW_ENSURE_GETPTR(thr, &js_ctx->bw, space);
-
-#if defined(DUK_USE_JX) && defined(DUK_USE_JC)
-       if (js_ctx->flag_ext_custom)
-#endif
-#if defined(DUK_USE_JX)
-       {
-               *q++ = DUK_ASC_PIPE;
-               q = duk__enc_buffer_data_hex(buf_data, buf_len, q);
-               *q++ = DUK_ASC_PIPE;
-
-       }
-#endif
-#if defined(DUK_USE_JX) && defined(DUK_USE_JC)
-       else
-#endif
-#if defined(DUK_USE_JC)
-       {
-               DUK_ASSERT(js_ctx->flag_ext_compatible);
-               DUK_MEMCPY((void *) q, (const void *) "{\"_buf\":\"", 9);  /* len: 9 */
-               q += 9;
-               q = duk__enc_buffer_data_hex(buf_data, buf_len, q);
-               *q++ = DUK_ASC_DOUBLEQUOTE;
-               *q++ = DUK_ASC_RCURLY;
-       }
-#endif
-
-       DUK_BW_SET_PTR(thr, &js_ctx->bw, q);
-}
-
-DUK_LOCAL void duk__enc_buffer(duk_json_enc_ctx *js_ctx, duk_hbuffer *h) {
-       duk__enc_buffer_data(js_ctx,
-                            (duk_uint8_t *) DUK_HBUFFER_GET_DATA_PTR(js_ctx->thr->heap, h),
-                            (duk_size_t) DUK_HBUFFER_GET_SIZE(h));
-}
-#endif  /* DUK_USE_JX || DUK_USE_JC */
-
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-DUK_LOCAL void duk__enc_pointer(duk_json_enc_ctx *js_ctx, void *ptr) {
-       char buf[64];  /* XXX: how to figure correct size? */
-       const char *fmt;
-
-       DUK_ASSERT(js_ctx->flag_ext_custom || js_ctx->flag_ext_compatible);  /* caller checks */
-       DUK_ASSERT(js_ctx->flag_ext_custom_or_compatible);
-
-       DUK_MEMZERO(buf, sizeof(buf));
-
-       /* The #ifdef clutter here needs to handle the three cases:
-        * (1) JX+JC, (2) JX only, (3) JC only.
-        */
-#if defined(DUK_USE_JX) && defined(DUK_USE_JC)
-       if (js_ctx->flag_ext_custom)
-#endif
-#if defined(DUK_USE_JX)
-       {
-               fmt = ptr ? "(%p)" : "(null)";
-       }
-#endif
-#if defined(DUK_USE_JX) && defined(DUK_USE_JC)
-       else
-#endif
-#if defined(DUK_USE_JC)
-       {
-               DUK_ASSERT(js_ctx->flag_ext_compatible);
-               fmt = ptr ? "{\"_ptr\":\"%p\"}" : "{\"_ptr\":\"null\"}";
-       }
-#endif
-
-       /* When ptr == NULL, the format argument is unused. */
-       DUK_SNPRINTF(buf, sizeof(buf) - 1, fmt, ptr);  /* must not truncate */
-       DUK__EMIT_CSTR(js_ctx, buf);
-}
-#endif  /* DUK_USE_JX || DUK_USE_JC */
-
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-DUK_LOCAL void duk__enc_bufferobject(duk_json_enc_ctx *js_ctx, duk_hbufferobject *h_bufobj) {
-       DUK_ASSERT_HBUFFEROBJECT_VALID(h_bufobj);
-
-       if (h_bufobj->buf == NULL || !DUK_HBUFFEROBJECT_VALID_SLICE(h_bufobj)) {
-               DUK__EMIT_STRIDX(js_ctx, DUK_STRIDX_LC_NULL);
-       } else {
-               /* Handle both full and partial slice (as long as covered). */
-               duk__enc_buffer_data(js_ctx,
-                                    (duk_uint8_t *) DUK_HBUFFEROBJECT_GET_SLICE_BASE(js_ctx->thr->heap, h_bufobj),
-                                    (duk_size_t) h_bufobj->length);
-       }
-}
-#endif  /* DUK_USE_JX || DUK_USE_JC */
-
-/* Indent helper.  Calling code relies on js_ctx->recursion_depth also being
- * directly related to indent depth.
- */
-#if defined(DUK_USE_PREFER_SIZE)
-DUK_LOCAL void duk__enc_newline_indent(duk_json_enc_ctx *js_ctx, duk_int_t depth) {
-       DUK_ASSERT(js_ctx->h_gap != NULL);
-       DUK_ASSERT(DUK_HSTRING_GET_BYTELEN(js_ctx->h_gap) > 0);  /* caller guarantees */
-
-       DUK__EMIT_1(js_ctx, 0x0a);
-       while (depth-- > 0) {
-               DUK__EMIT_HSTR(js_ctx, js_ctx->h_gap);
-       }
-}
-#else  /* DUK_USE_PREFER_SIZE */
-DUK_LOCAL void duk__enc_newline_indent(duk_json_enc_ctx *js_ctx, duk_int_t depth) {
-       const duk_uint8_t *gap_data;
-       duk_size_t gap_len;
-       duk_size_t avail_bytes;   /* bytes of indent available for copying */
-       duk_size_t need_bytes;    /* bytes of indent still needed */
-       duk_uint8_t *p_start;
-       duk_uint8_t *p;
-
-       DUK_ASSERT(js_ctx->h_gap != NULL);
-       DUK_ASSERT(DUK_HSTRING_GET_BYTELEN(js_ctx->h_gap) > 0);  /* caller guarantees */
-
-       DUK__EMIT_1(js_ctx, 0x0a);
-       if (DUK_UNLIKELY(depth == 0)) {
-               return;
-       }
-
-       /* To handle deeper indents efficiently, make use of copies we've
-        * already emitted.  In effect we can emit a sequence of 1, 2, 4,
-        * 8, etc copies, and then finish the last run.  Byte counters
-        * avoid multiply with gap_len on every loop.
-        */
-
-       gap_data = (const duk_uint8_t *) DUK_HSTRING_GET_DATA(js_ctx->h_gap);
-       gap_len = (duk_size_t) DUK_HSTRING_GET_BYTELEN(js_ctx->h_gap);
-       DUK_ASSERT(gap_len > 0);
-
-       need_bytes = gap_len * depth;
-       p = DUK_BW_ENSURE_GETPTR(js_ctx->thr, &js_ctx->bw, need_bytes);
-       p_start = p;
-
-       DUK_MEMCPY((void *) p, (const void *) gap_data, (size_t) gap_len);
-       p += gap_len;
-       avail_bytes = gap_len;
-       DUK_ASSERT(need_bytes >= gap_len);
-       need_bytes -= gap_len;
-
-       while (need_bytes >= avail_bytes) {
-               DUK_MEMCPY((void *) p, (const void *) p_start, (size_t) avail_bytes);
-               p += avail_bytes;
-               need_bytes -= avail_bytes;
-               avail_bytes <<= 1;
-       }
-
-       DUK_ASSERT(need_bytes < avail_bytes);  /* need_bytes may be zero */
-       DUK_MEMCPY((void *) p, (const void *) p_start, (size_t) need_bytes);
-       p += need_bytes;
-       /*avail_bytes += need_bytes*/
-
-       DUK_BW_SET_PTR(js_ctx->thr, &js_ctx->bw, p);
-}
-#endif  /* DUK_USE_PREFER_SIZE */
-
-/* Shared entry handling for object/array serialization. */
-DUK_LOCAL void duk__enc_objarr_entry(duk_json_enc_ctx *js_ctx, duk_idx_t *entry_top) {
-       duk_context *ctx = (duk_context *) js_ctx->thr;
-       duk_hobject *h_target;
-       duk_uint_fast32_t i, n;
-
-       *entry_top = duk_get_top(ctx);
-
-       duk_require_stack(ctx, DUK_JSON_ENC_REQSTACK);
-
-       /* Loop check using a hybrid approach: a fixed-size visited[] array
-        * with overflow in a loop check object.
-        */
-
-       h_target = duk_get_hobject(ctx, -1);  /* object or array */
-       DUK_ASSERT(h_target != NULL);
-
-       n = js_ctx->recursion_depth;
-       if (DUK_UNLIKELY(n > DUK_JSON_ENC_LOOPARRAY)) {
-               n = DUK_JSON_ENC_LOOPARRAY;
-       }
-       for (i = 0; i < n; i++) {
-               if (DUK_UNLIKELY(js_ctx->visiting[i] == h_target)) {
-                       DUK_DD(DUK_DDPRINT("slow path loop detect"));
-                       DUK_ERROR_TYPE((duk_hthread *) ctx, DUK_STR_CYCLIC_INPUT);
-               }
-       }
-       if (js_ctx->recursion_depth < DUK_JSON_ENC_LOOPARRAY) {
-               js_ctx->visiting[js_ctx->recursion_depth] = h_target;
-       } else {
-               duk_push_sprintf(ctx, DUK_STR_FMT_PTR, (void *) h_target);
-               duk_dup_top(ctx);  /* -> [ ... voidp voidp ] */
-               if (duk_has_prop(ctx, js_ctx->idx_loop)) {
-                       DUK_ERROR_TYPE((duk_hthread *) ctx, DUK_STR_CYCLIC_INPUT);
-               }
-               duk_push_true(ctx);  /* -> [ ... voidp true ] */
-               duk_put_prop(ctx, js_ctx->idx_loop);  /* -> [ ... ] */
-       }
-
-       /* C recursion check. */
-
-       DUK_ASSERT(js_ctx->recursion_depth >= 0);
-       DUK_ASSERT(js_ctx->recursion_depth <= js_ctx->recursion_limit);
-       if (js_ctx->recursion_depth >= js_ctx->recursion_limit) {
-               DUK_ERROR_RANGE((duk_hthread *) ctx, DUK_STR_JSONENC_RECLIMIT);
-       }
-       js_ctx->recursion_depth++;
-
-       DUK_DDD(DUK_DDDPRINT("shared entry finished: top=%ld, loop=%!T",
-                            (long) duk_get_top(ctx), (duk_tval *) duk_get_tval(ctx, js_ctx->idx_loop)));
-}
-
-/* Shared exit handling for object/array serialization. */
-DUK_LOCAL void duk__enc_objarr_exit(duk_json_enc_ctx *js_ctx, duk_idx_t *entry_top) {
-       duk_context *ctx = (duk_context *) js_ctx->thr;
-       duk_hobject *h_target;
-
-       /* C recursion check. */
-
-       DUK_ASSERT(js_ctx->recursion_depth > 0);
-       DUK_ASSERT(js_ctx->recursion_depth <= js_ctx->recursion_limit);
-       js_ctx->recursion_depth--;
-
-       /* Loop check. */
-
-       h_target = duk_get_hobject(ctx, *entry_top - 1);  /* original target at entry_top - 1 */
-       DUK_ASSERT(h_target != NULL);
-
-       if (js_ctx->recursion_depth < DUK_JSON_ENC_LOOPARRAY) {
-               /* Previous entry was inside visited[], nothing to do. */
-       } else {
-               duk_push_sprintf(ctx, DUK_STR_FMT_PTR, (void *) h_target);
-               duk_del_prop(ctx, js_ctx->idx_loop);  /* -> [ ... ] */
-       }
-
-       /* Restore stack top after unbalanced code paths. */
-       duk_set_top(ctx, *entry_top);
-
-       DUK_DDD(DUK_DDDPRINT("shared entry finished: top=%ld, loop=%!T",
-                            (long) duk_get_top(ctx), (duk_tval *) duk_get_tval(ctx, js_ctx->idx_loop)));
-}
-
-/* The JO(value) operation: encode object.
- *
- * Stack policy: [ object ] -> [ object ].
- */
-DUK_LOCAL void duk__enc_object(duk_json_enc_ctx *js_ctx) {
-       duk_context *ctx = (duk_context *) js_ctx->thr;
-       duk_hstring *h_key;
-       duk_idx_t entry_top;
-       duk_idx_t idx_obj;
-       duk_idx_t idx_keys;
-       duk_bool_t emitted;
-       duk_uarridx_t arr_len, i;
-       duk_size_t prev_size;
-
-       DUK_DDD(DUK_DDDPRINT("duk__enc_object: obj=%!T", (duk_tval *) duk_get_tval(ctx, -1)));
-
-       duk__enc_objarr_entry(js_ctx, &entry_top);
-
-       idx_obj = entry_top - 1;
-
-       if (js_ctx->idx_proplist >= 0) {
-               idx_keys = js_ctx->idx_proplist;
-       } else {
-               /* XXX: would be nice to enumerate an object at specified index */
-               duk_dup(ctx, idx_obj);
-               (void) duk_hobject_get_enumerated_keys(ctx, DUK_ENUM_OWN_PROPERTIES_ONLY /*flags*/);  /* [ ... target ] -> [ ... target keys ] */
-               idx_keys = duk_require_normalize_index(ctx, -1);
-               /* leave stack unbalanced on purpose */
-       }
-
-       DUK_DDD(DUK_DDDPRINT("idx_keys=%ld, h_keys=%!T",
-                            (long) idx_keys, (duk_tval *) duk_get_tval(ctx, idx_keys)));
-
-       /* Steps 8-10 have been merged to avoid a "partial" variable. */
-
-       DUK__EMIT_1(js_ctx, DUK_ASC_LCURLY);
-
-       /* XXX: keys is an internal object with all keys to be processed
-        * in its (gapless) array part.  Because nobody can touch the keys
-        * object, we could iterate its array part directly (keeping in mind
-        * that it can be reallocated).
-        */
-
-       arr_len = (duk_uarridx_t) duk_get_length(ctx, idx_keys);
-       emitted = 0;
-       for (i = 0; i < arr_len; i++) {
-               duk_get_prop_index(ctx, idx_keys, i);  /* -> [ ... key ] */
-
-               DUK_DDD(DUK_DDDPRINT("object property loop: holder=%!T, key=%!T",
-                                    (duk_tval *) duk_get_tval(ctx, idx_obj),
-                                    (duk_tval *) duk_get_tval(ctx, -1)));
-
-               h_key = duk_get_hstring(ctx, -1);
-               DUK_ASSERT(h_key != NULL);
-
-               prev_size = DUK_BW_GET_SIZE(js_ctx->thr, &js_ctx->bw);
-               if (DUK_UNLIKELY(js_ctx->h_gap != NULL)) {
-                       duk__enc_newline_indent(js_ctx, js_ctx->recursion_depth);
-                       duk__enc_key_autoquote(js_ctx, h_key);
-                       DUK__EMIT_2(js_ctx, DUK_ASC_COLON, DUK_ASC_SPACE);
-               } else {
-                       duk__enc_key_autoquote(js_ctx, h_key);
-                       DUK__EMIT_1(js_ctx, DUK_ASC_COLON);
-               }
-
-               /* [ ... key ] */
-
-               if (DUK_UNLIKELY(duk__enc_value(js_ctx, idx_obj) == 0)) {
-                       /* Value would yield 'undefined', so skip key altogether.
-                        * Side effects have already happened.
-                        */
-                       DUK_BW_SET_SIZE(js_ctx->thr, &js_ctx->bw, prev_size);
-               } else {
-                       DUK__EMIT_1(js_ctx, DUK_ASC_COMMA);
-                       emitted = 1;
-               }
-
-               /* [ ... ] */
-       }
-
-       if (emitted) {
-               DUK_ASSERT(*((duk_uint8_t *) DUK_BW_GET_PTR(js_ctx->thr, &js_ctx->bw) - 1) == DUK_ASC_COMMA);
-               DUK__UNEMIT_1(js_ctx);  /* eat trailing comma */
-               if (DUK_UNLIKELY(js_ctx->h_gap != NULL)) {
-                       DUK_ASSERT(js_ctx->recursion_depth >= 1);
-                       duk__enc_newline_indent(js_ctx, js_ctx->recursion_depth - 1);
-               }
-       }
-       DUK__EMIT_1(js_ctx, DUK_ASC_RCURLY);
-
-       duk__enc_objarr_exit(js_ctx, &entry_top);
-
-       DUK_ASSERT_TOP(ctx, entry_top);
-}
-
-/* The JA(value) operation: encode array.
- *
- * Stack policy: [ array ] -> [ array ].
- */
-DUK_LOCAL void duk__enc_array(duk_json_enc_ctx *js_ctx) {
-       duk_context *ctx = (duk_context *) js_ctx->thr;
-       duk_idx_t entry_top;
-       duk_idx_t idx_arr;
-       duk_bool_t emitted;
-       duk_uarridx_t i, arr_len;
-
-       DUK_DDD(DUK_DDDPRINT("duk__enc_array: array=%!T",
-                            (duk_tval *) duk_get_tval(ctx, -1)));
-
-       duk__enc_objarr_entry(js_ctx, &entry_top);
-
-       idx_arr = entry_top - 1;
-
-       /* Steps 8-10 have been merged to avoid a "partial" variable. */
-
-       DUK__EMIT_1(js_ctx, DUK_ASC_LBRACKET);
-
-       arr_len = (duk_uarridx_t) duk_get_length(ctx, idx_arr);
-       emitted = 0;
-       for (i = 0; i < arr_len; i++) {
-               DUK_DDD(DUK_DDDPRINT("array entry loop: array=%!T, index=%ld, arr_len=%ld",
-                                    (duk_tval *) duk_get_tval(ctx, idx_arr),
-                                    (long) i, (long) arr_len));
-
-               if (DUK_UNLIKELY(js_ctx->h_gap != NULL)) {
-                       DUK_ASSERT(js_ctx->recursion_depth >= 1);
-                       duk__enc_newline_indent(js_ctx, js_ctx->recursion_depth);
-               }
-
-               /* XXX: duk_push_uint_string() */
-               duk_push_uint(ctx, (duk_uint_t) i);
-               duk_to_string(ctx, -1);  /* -> [ ... key ] */
-
-               /* [ ... key ] */
-
-               if (DUK_UNLIKELY(duk__enc_value(js_ctx, idx_arr) == 0)) {
-                       /* Value would normally be omitted, replace with 'null'. */
-                       DUK__EMIT_STRIDX(js_ctx, DUK_STRIDX_LC_NULL);
-               } else {
-                       ;
-               }
-
-               /* [ ... ] */
-
-               DUK__EMIT_1(js_ctx, DUK_ASC_COMMA);
-               emitted = 1;
-       }
-
-       if (emitted) {
-               DUK_ASSERT(*((duk_uint8_t *) DUK_BW_GET_PTR(js_ctx->thr, &js_ctx->bw) - 1) == DUK_ASC_COMMA);
-               DUK__UNEMIT_1(js_ctx);  /* eat trailing comma */
-               if (DUK_UNLIKELY(js_ctx->h_gap != NULL)) {
-                       DUK_ASSERT(js_ctx->recursion_depth >= 1);
-                       duk__enc_newline_indent(js_ctx, js_ctx->recursion_depth - 1);
-               }
-       }
-       DUK__EMIT_1(js_ctx, DUK_ASC_RBRACKET);
-
-       duk__enc_objarr_exit(js_ctx, &entry_top);
-
-       DUK_ASSERT_TOP(ctx, entry_top);
-}
-
-/* The Str(key, holder) operation.
- *
- * Stack policy: [ ... key ] -> [ ... ]
- */
-DUK_LOCAL duk_bool_t duk__enc_value(duk_json_enc_ctx *js_ctx, duk_idx_t idx_holder) {
-       duk_context *ctx = (duk_context *) js_ctx->thr;
-       duk_hthread *thr = (duk_hthread *) ctx;
-       duk_hobject *h_tmp;
-       duk_tval *tv;
-       duk_tval *tv_holder;
-       duk_tval *tv_key;
-       duk_small_int_t c;
-
-       DUK_DDD(DUK_DDDPRINT("duk__enc_value: idx_holder=%ld, holder=%!T, key=%!T",
-                            (long) idx_holder, (duk_tval *) duk_get_tval(ctx, idx_holder),
-                            (duk_tval *) duk_get_tval(ctx, -1)));
-
-       DUK_UNREF(thr);
-
-       tv_holder = DUK_GET_TVAL_POSIDX(ctx, idx_holder);
-       DUK_ASSERT(DUK_TVAL_IS_OBJECT(tv_holder));
-       tv_key = DUK_GET_TVAL_NEGIDX(ctx, -1);
-       DUK_ASSERT(DUK_TVAL_IS_STRING(tv_key));
-       (void) duk_hobject_getprop(thr, tv_holder, tv_key);
-
-       /* -> [ ... key val ] */
-
-       DUK_DDD(DUK_DDDPRINT("value=%!T", (duk_tval *) duk_get_tval(ctx, -1)));
-
-       h_tmp = duk_get_hobject_or_lfunc_coerce(ctx, -1);
-       if (h_tmp != NULL) {
-               duk_get_prop_stridx(ctx, -1, DUK_STRIDX_TO_JSON);
-               h_tmp = duk_get_hobject_or_lfunc_coerce(ctx, -1);  /* toJSON() can also be a lightfunc */
-
-               if (h_tmp != NULL && DUK_HOBJECT_IS_CALLABLE(h_tmp)) {
-                       DUK_DDD(DUK_DDDPRINT("value is object, has callable toJSON() -> call it"));
-                       /* XXX: duk_dup_unvalidated(ctx, -2) etc. */
-                       duk_dup(ctx, -2);         /* -> [ ... key val toJSON val ] */
-                       duk_dup(ctx, -4);         /* -> [ ... key val toJSON val key ] */
-                       duk_call_method(ctx, 1);  /* -> [ ... key val val' ] */
-                       duk_remove(ctx, -2);      /* -> [ ... key val' ] */
-               } else {
-                       duk_pop(ctx);             /* -> [ ... key val ] */
-               }
-       }
-
-       /* [ ... key val ] */
-
-       DUK_DDD(DUK_DDDPRINT("value=%!T", (duk_tval *) duk_get_tval(ctx, -1)));
-
-       if (js_ctx->h_replacer) {
-               /* XXX: Here a "slice copy" would be useful. */
-               DUK_DDD(DUK_DDDPRINT("replacer is set, call replacer"));
-               duk_push_hobject(ctx, js_ctx->h_replacer);  /* -> [ ... key val replacer ] */
-               duk_dup(ctx, idx_holder);                   /* -> [ ... key val replacer holder ] */
-               duk_dup(ctx, -4);                           /* -> [ ... key val replacer holder key ] */
-               duk_dup(ctx, -4);                           /* -> [ ... key val replacer holder key val ] */
-               duk_call_method(ctx, 2);                    /* -> [ ... key val val' ] */
-               duk_remove(ctx, -2);                        /* -> [ ... key val' ] */
-       }
-
-       /* [ ... key val ] */
-
-       DUK_DDD(DUK_DDDPRINT("value=%!T", (duk_tval *) duk_get_tval(ctx, -1)));
-
-       tv = DUK_GET_TVAL_NEGIDX(ctx, -1);
-       if (DUK_TVAL_IS_OBJECT(tv)) {
-               duk_hobject *h;
-
-               h = DUK_TVAL_GET_OBJECT(tv);
-               DUK_ASSERT(h != NULL);
-
-               if (DUK_HOBJECT_IS_BUFFEROBJECT(h)) {
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-                       duk_hbufferobject *h_bufobj;
-                       h_bufobj = (duk_hbufferobject *) h;
-                       DUK_ASSERT_HBUFFEROBJECT_VALID(h_bufobj);
-
-                       /* Conceptually we'd extract the plain underlying buffer
-                        * or its slice and then do a type mask check below to
-                        * see if we should reject it.  Do the mask check here
-                        * instead to avoid making a copy of the buffer slice.
-                        */
-
-                       if (js_ctx->mask_for_undefined & DUK_TYPE_MASK_BUFFER) {
-                               DUK_DDD(DUK_DDDPRINT("-> bufferobject (-> plain buffer) will result in undefined (type mask check)"));
-                               goto pop2_undef;
-                       }
-                       DUK_DDD(DUK_DDDPRINT("-> bufferobject won't result in undefined, encode directly"));
-                       duk__enc_bufferobject(js_ctx, h_bufobj);
-                       goto pop2_emitted;
-#else
-                       DUK_DDD(DUK_DDDPRINT("no JX/JC support, bufferobject/buffer will always result in undefined"));
-                       goto pop2_undef;
-#endif
-               } else {
-                       c = (duk_small_int_t) DUK_HOBJECT_GET_CLASS_NUMBER(h);
-                       switch ((int) c) {
-                       case DUK_HOBJECT_CLASS_NUMBER: {
-                               DUK_DDD(DUK_DDDPRINT("value is a Number object -> coerce with ToNumber()"));
-                               duk_to_number(ctx, -1);
-                               /* The coercion potentially invokes user .valueOf() and .toString()
-                                * but can't result in a function value because [[DefaultValue]] would
-                                * reject such a result: test-dev-json-stringify-coercion-1.js.
-                                */
-                               DUK_ASSERT(!duk_is_callable(ctx, -1));
-                               break;
-                       }
-                       case DUK_HOBJECT_CLASS_STRING: {
-                               DUK_DDD(DUK_DDDPRINT("value is a String object -> coerce with ToString()"));
-                               duk_to_string(ctx, -1);
-                               /* Same coercion behavior as for Number. */
-                               DUK_ASSERT(!duk_is_callable(ctx, -1));
-                               break;
-                       }
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-                       case DUK_HOBJECT_CLASS_POINTER:
-#endif
-                       case DUK_HOBJECT_CLASS_BOOLEAN: {
-                               DUK_DDD(DUK_DDDPRINT("value is a Boolean/Buffer/Pointer object -> get internal value"));
-                               duk_get_prop_stridx(ctx, -1, DUK_STRIDX_INT_VALUE);
-                               duk_remove(ctx, -2);
-                               break;
-                       }
-                       default: {
-                               /* Normal object which doesn't get automatically coerced to a
-                                * primitive value.  Functions are checked for specially.  The
-                                * primitive value coercions for Number, String, Pointer, and
-                                * Boolean can't result in functions so suffices to check here.
-                                */
-                               DUK_ASSERT(h != NULL);
-                               if (DUK_HOBJECT_IS_CALLABLE(h)) {
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-                                       if (js_ctx->flags & (DUK_JSON_FLAG_EXT_CUSTOM |
-                                                            DUK_JSON_FLAG_EXT_COMPATIBLE)) {
-                                               /* We only get here when doing non-standard JSON encoding */
-                                               DUK_DDD(DUK_DDDPRINT("-> function allowed, serialize to custom format"));
-                                               DUK_ASSERT(js_ctx->flag_ext_custom || js_ctx->flag_ext_compatible);
-                                               DUK__EMIT_STRIDX(js_ctx, js_ctx->stridx_custom_function);
-                                               goto pop2_emitted;
-                                       } else {
-                                               DUK_DDD(DUK_DDDPRINT("-> will result in undefined (function)"));
-                                               goto pop2_undef;
-                                       }
-#else  /* DUK_USE_JX || DUK_USE_JC */
-                                       DUK_DDD(DUK_DDDPRINT("-> will result in undefined (function)"));
-                                       goto pop2_undef;
-#endif  /* DUK_USE_JX || DUK_USE_JC */
-                               }
-                       }
-                       }  /* end switch */
-               }
-       }
-
-       /* [ ... key val ] */
-
-       DUK_DDD(DUK_DDDPRINT("value=%!T", (duk_tval *) duk_get_tval(ctx, -1)));
-
-       if (duk_check_type_mask(ctx, -1, js_ctx->mask_for_undefined)) {
-               /* will result in undefined */
-               DUK_DDD(DUK_DDDPRINT("-> will result in undefined (type mask check)"));
-               goto pop2_undef;
-       }
-       tv = DUK_GET_TVAL_NEGIDX(ctx, -1);
-
-       switch (DUK_TVAL_GET_TAG(tv)) {
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-       /* When JX/JC not in use, the type mask above will avoid this case if needed. */
-       case DUK_TAG_UNDEFINED: {
-               DUK__EMIT_STRIDX(js_ctx, js_ctx->stridx_custom_undefined);
-               break;
-       }
-#endif
-       case DUK_TAG_NULL: {
-               DUK__EMIT_STRIDX(js_ctx, DUK_STRIDX_LC_NULL);
-               break;
-       }
-       case DUK_TAG_BOOLEAN: {
-               DUK__EMIT_STRIDX(js_ctx, DUK_TVAL_GET_BOOLEAN(tv) ?
-                                DUK_STRIDX_TRUE : DUK_STRIDX_FALSE);
-               break;
-       }
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-       /* When JX/JC not in use, the type mask above will avoid this case if needed. */
-       case DUK_TAG_POINTER: {
-               duk__enc_pointer(js_ctx, DUK_TVAL_GET_POINTER(tv));
-               break;
-       }
-#endif  /* DUK_USE_JX || DUK_USE_JC */
-       case DUK_TAG_STRING: {
-               duk_hstring *h = DUK_TVAL_GET_STRING(tv);
-               DUK_ASSERT(h != NULL);
-
-               duk__enc_quote_string(js_ctx, h);
-               break;
-       }
-       case DUK_TAG_OBJECT: {
-               duk_hobject *h = DUK_TVAL_GET_OBJECT(tv);
-               DUK_ASSERT(h != NULL);
-
-               /* Function values are handled completely above (including
-                * coercion results):
-                */
-               DUK_ASSERT(!DUK_HOBJECT_IS_CALLABLE(h));
-
-               if (DUK_HOBJECT_GET_CLASS_NUMBER(h) == DUK_HOBJECT_CLASS_ARRAY) {
-                       duk__enc_array(js_ctx);
-               } else {
-                       duk__enc_object(js_ctx);
-               }
-               break;
-       }
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-       /* When JX/JC not in use, the type mask above will avoid this case if needed. */
-       case DUK_TAG_BUFFER: {
-               duk__enc_buffer(js_ctx, DUK_TVAL_GET_BUFFER(tv));
-               break;
-       }
-#endif  /* DUK_USE_JX || DUK_USE_JC */
-       case DUK_TAG_LIGHTFUNC: {
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-               /* We only get here when doing non-standard JSON encoding */
-               DUK_ASSERT(js_ctx->flag_ext_custom || js_ctx->flag_ext_compatible);
-               DUK__EMIT_STRIDX(js_ctx, js_ctx->stridx_custom_function);
-#else
-               /* Standard JSON omits functions */
-               DUK_UNREACHABLE();
-#endif
-               break;
-       }
-#if defined(DUK_USE_FASTINT)
-       case DUK_TAG_FASTINT:
-               /* Number serialization has a significant impact relative to
-                * other fast path code, so careful fast path for fastints.
-                */
-               duk__enc_fastint_tval(js_ctx, tv);
-               break;
-#endif
-       default: {
-               /* number */
-               DUK_ASSERT(!DUK_TVAL_IS_UNUSED(tv));
-               DUK_ASSERT(DUK_TVAL_IS_NUMBER(tv));
-               /* XXX: A fast path for usual integers would be useful when
-                * fastint support is not enabled.
-                */
-               duk__enc_double(js_ctx);
-               break;
-       }
-       }
-
- pop2_emitted:
-       duk_pop_2(ctx); /* [ ... key val ] -> [ ... ] */
-       return 1;  /* emitted */
-
- pop2_undef:
-       duk_pop_2(ctx);  /* [ ... key val ] -> [ ... ] */
-       return 0;  /* not emitted */
-}
-
-/* E5 Section 15.12.3, main algorithm, step 4.b.ii steps 1-4. */
-DUK_LOCAL duk_bool_t duk__enc_allow_into_proplist(duk_tval *tv) {
-       duk_hobject *h;
-       duk_small_int_t c;
-
-       DUK_ASSERT(tv != NULL);
-       if (DUK_TVAL_IS_STRING(tv) || DUK_TVAL_IS_NUMBER(tv)) {
-               return 1;
-       } else if (DUK_TVAL_IS_OBJECT(tv)) {
-               h = DUK_TVAL_GET_OBJECT(tv);
-               DUK_ASSERT(h != NULL);
-               c = (duk_small_int_t) DUK_HOBJECT_GET_CLASS_NUMBER(h);
-               if (c == DUK_HOBJECT_CLASS_STRING || c == DUK_HOBJECT_CLASS_NUMBER) {
-                       return 1;
-               }
-       }
-
-       return 0;
-}
-
-/*
- *  JSON.stringify() fast path
- *
- *  Otherwise supports full JSON, JX, and JC features, but bails out on any
- *  possible side effect which might change the value being serialized.  The
- *  fast path can take advantage of the fact that the value being serialized
- *  is unchanged so that we can walk directly through property tables etc.
- */
-
-#if defined(DUK_USE_JSON_STRINGIFY_FASTPATH)
-DUK_LOCAL duk_bool_t duk__json_stringify_fast_value(duk_json_enc_ctx *js_ctx, duk_tval *tv) {
-       duk_uint_fast32_t i, n;
-
-       DUK_DDD(DUK_DDDPRINT("stringify fast: %!T", tv));
-
-       DUK_ASSERT(js_ctx != NULL);
-       DUK_ASSERT(js_ctx->thr != NULL);
-
-#if 0 /* disabled for now */
- restart_match:
-#endif
-
-       DUK_ASSERT(tv != NULL);
-
-       switch (DUK_TVAL_GET_TAG(tv)) {
-       case DUK_TAG_UNDEFINED: {
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-               if (js_ctx->flag_ext_custom || js_ctx->flag_ext_compatible) {
-                       DUK__EMIT_STRIDX(js_ctx, js_ctx->stridx_custom_undefined);
-                       break;
-               } else {
-                       goto emit_undefined;
-               }
-#else
-               goto emit_undefined;
-#endif
-       }
-       case DUK_TAG_NULL: {
-               DUK__EMIT_STRIDX(js_ctx, DUK_STRIDX_LC_NULL);
-               break;
-       }
-       case DUK_TAG_BOOLEAN: {
-               DUK__EMIT_STRIDX(js_ctx, DUK_TVAL_GET_BOOLEAN(tv) ?
-                                DUK_STRIDX_TRUE : DUK_STRIDX_FALSE);
-               break;
-       }
-       case DUK_TAG_STRING: {
-               duk_hstring *h;
-
-               h = DUK_TVAL_GET_STRING(tv);
-               DUK_ASSERT(h != NULL);
-               duk__enc_quote_string(js_ctx, h);
-               break;
-       }
-       case DUK_TAG_OBJECT: {
-               duk_hobject *obj;
-               duk_tval *tv_val;
-               duk_bool_t emitted = 0;
-               duk_uint32_t c_bit, c_all, c_array, c_unbox, c_undef,
-                            c_func, c_bufobj, c_object;
-
-               /* For objects JSON.stringify() only looks for own, enumerable
-                * properties which is nice for the fast path here.
-                *
-                * For arrays JSON.stringify() uses [[Get]] so it will actually
-                * inherit properties during serialization!  This fast path
-                * supports gappy arrays as long as there's no actual inherited
-                * property (which might be a getter etc).
-                *
-                * Since recursion only happens for objects, we can have both
-                * recursion and loop checks here.  We use a simple, depth-limited
-                * loop check in the fast path because the object-based tracking
-                * is very slow (when tested, it accounted for 50% of fast path
-                * execution time for input data with a lot of small objects!).
-                */
-
-               /* XXX: for real world code, could just ignore array inheritance
-                * and only look at array own properties.
-                */
-
-               /* We rely on a few object flag / class number relationships here,
-                * assert for them.
-                */
-
-               obj = DUK_TVAL_GET_OBJECT(tv);
-               DUK_ASSERT(obj != NULL);
-               DUK_ASSERT_HOBJECT_VALID(obj);
-
-               /* Once recursion depth is increased, exit path must decrease
-                * it (though it's OK to abort the fast path).
-                */
-
-               DUK_ASSERT(js_ctx->recursion_depth >= 0);
-               DUK_ASSERT(js_ctx->recursion_depth <= js_ctx->recursion_limit);
-               if (js_ctx->recursion_depth >= js_ctx->recursion_limit) {
-                       DUK_DD(DUK_DDPRINT("fast path recursion limit"));
-                       DUK_ERROR_RANGE(js_ctx->thr, DUK_STR_JSONDEC_RECLIMIT);
-               }
-
-               for (i = 0, n = (duk_uint_fast32_t) js_ctx->recursion_depth; i < n; i++) {
-                       if (DUK_UNLIKELY(js_ctx->visiting[i] == obj)) {
-                               DUK_DD(DUK_DDPRINT("fast path loop detect"));
-                               DUK_ERROR_TYPE(js_ctx->thr, DUK_STR_CYCLIC_INPUT);
-                       }
-               }
-
-               /* Guaranteed by recursion_limit setup so we don't have to
-                * check twice.
-                */
-               DUK_ASSERT(js_ctx->recursion_depth < DUK_JSON_ENC_LOOPARRAY);
-               js_ctx->visiting[js_ctx->recursion_depth] = obj;
-               js_ctx->recursion_depth++;
-
-               /* If object has a .toJSON() property, we can't be certain
-                * that it wouldn't mutate any value arbitrarily, so bail
-                * out of the fast path.
-                *
-                * If an object is a Proxy we also can't avoid side effects
-                * so abandon.
-                */
-               /* XXX: non-callable .toJSON() doesn't need to cause an abort
-                * but does at the moment, probably not worth fixing.
-                */
-               if (duk_hobject_hasprop_raw(js_ctx->thr, obj, DUK_HTHREAD_STRING_TO_JSON(js_ctx->thr)) ||
-                   DUK_HOBJECT_HAS_EXOTIC_PROXYOBJ(obj)) {
-                       DUK_DD(DUK_DDPRINT("object has a .toJSON property or object is a Proxy, abort fast path"));
-                       goto abort_fastpath;
-               }
-
-               /* We could use a switch-case for the class number but it turns out
-                * a small if-else ladder on class masks is better.  The if-ladder
-                * should be in order of relevancy.
-                */
-
-               /* XXX: move masks to js_ctx? they don't change during one
-                * fast path invocation.
-                */
-               DUK_ASSERT(DUK_HOBJECT_CLASS_MAX <= 31);
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-               if (js_ctx->flag_ext_custom_or_compatible) {
-                       c_all = DUK_HOBJECT_CMASK_ALL;
-                       c_array = DUK_HOBJECT_CMASK_ARRAY;
-                       c_unbox = DUK_HOBJECT_CMASK_NUMBER |
-                                 DUK_HOBJECT_CMASK_STRING |
-                                 DUK_HOBJECT_CMASK_BOOLEAN |
-                                 DUK_HOBJECT_CMASK_POINTER;
-                       c_func = DUK_HOBJECT_CMASK_FUNCTION;
-                       c_bufobj = DUK_HOBJECT_CMASK_ALL_BUFFEROBJECTS;
-                       c_undef = 0;
-                       c_object = c_all & ~(c_array | c_unbox | c_func | c_bufobj | c_undef);
-               }
-               else
-#endif
-               {
-                       c_all = DUK_HOBJECT_CMASK_ALL;
-                       c_array = DUK_HOBJECT_CMASK_ARRAY;
-                       c_unbox = DUK_HOBJECT_CMASK_NUMBER |
-                                 DUK_HOBJECT_CMASK_STRING |
-                                 DUK_HOBJECT_CMASK_BOOLEAN;
-                       c_func = 0;
-                       c_bufobj = 0;
-                       c_undef = DUK_HOBJECT_CMASK_FUNCTION |
-                                 DUK_HOBJECT_CMASK_POINTER |
-                                 DUK_HOBJECT_CMASK_ALL_BUFFEROBJECTS;
-                       c_object = c_all & ~(c_array | c_unbox | c_func | c_bufobj | c_undef);
-               }
-
-               c_bit = DUK_HOBJECT_GET_CLASS_MASK(obj);
-               if (c_bit & c_object) {
-                       /* All other object types. */
-                       DUK__EMIT_1(js_ctx, DUK_ASC_LCURLY);
-
-                       /* A non-Array object should not have an array part in practice.
-                        * But since it is supported internally (and perhaps used at some
-                        * point), check and abandon if that's the case.
-                        */
-                       if (DUK_HOBJECT_HAS_ARRAY_PART(obj)) {
-                               DUK_DD(DUK_DDPRINT("non-Array object has array part, abort fast path"));
-                               goto abort_fastpath;
-                       }
-
-                       for (i = 0; i < (duk_uint_fast32_t) DUK_HOBJECT_GET_ENEXT(obj); i++) {
-                               duk_hstring *k;
-                               duk_size_t prev_size;
-
-                               k = DUK_HOBJECT_E_GET_KEY(js_ctx->thr->heap, obj, i);
-                               if (!k) {
-                                       continue;
-                               }
-                               if (!DUK_HOBJECT_E_SLOT_IS_ENUMERABLE(js_ctx->thr->heap, obj, i)) {
-                                       continue;
-                               }
-                               if (DUK_HOBJECT_E_SLOT_IS_ACCESSOR(js_ctx->thr->heap, obj, i)) {
-                                       /* Getter might have arbitrary side effects,
-                                        * so bail out.
-                                        */
-                                       DUK_DD(DUK_DDPRINT("property is an accessor, abort fast path"));
-                                       goto abort_fastpath;
-                               }
-                               if (DUK_HSTRING_HAS_INTERNAL(k)) {
-                                       continue;
-                               }
-
-                               tv_val = DUK_HOBJECT_E_GET_VALUE_TVAL_PTR(js_ctx->thr->heap, obj, i);
-
-                               prev_size = DUK_BW_GET_SIZE(js_ctx->thr, &js_ctx->bw);
-                               if (DUK_UNLIKELY(js_ctx->h_gap != NULL)) {
-                                       duk__enc_newline_indent(js_ctx, js_ctx->recursion_depth);
-                                       duk__enc_key_autoquote(js_ctx, k);
-                                       DUK__EMIT_2(js_ctx, DUK_ASC_COLON, DUK_ASC_SPACE);
-                               } else {
-                                       duk__enc_key_autoquote(js_ctx, k);
-                                       DUK__EMIT_1(js_ctx, DUK_ASC_COLON);
-                               }
-
-                               if (duk__json_stringify_fast_value(js_ctx, tv_val) == 0) {
-                                       DUK_DD(DUK_DDPRINT("prop value not supported, rewind key and colon"));
-                                       DUK_BW_SET_SIZE(js_ctx->thr, &js_ctx->bw, prev_size);
-                               } else {
-                                       DUK__EMIT_1(js_ctx, DUK_ASC_COMMA);
-                                       emitted = 1;
-                               }
-                       }
-
-                       /* If any non-Array value had enumerable virtual own
-                        * properties, they should be serialized here.  Standard
-                        * types don't.
-                        */
-
-                       if (emitted) {
-                               DUK_ASSERT(*((duk_uint8_t *) DUK_BW_GET_PTR(js_ctx->thr, &js_ctx->bw) - 1) == DUK_ASC_COMMA);
-                               DUK__UNEMIT_1(js_ctx);  /* eat trailing comma */
-                               if (DUK_UNLIKELY(js_ctx->h_gap != NULL)) {
-                                       DUK_ASSERT(js_ctx->recursion_depth >= 1);
-                                       duk__enc_newline_indent(js_ctx, js_ctx->recursion_depth - 1);
-                               }
-                       }
-                       DUK__EMIT_1(js_ctx, DUK_ASC_RCURLY);
-               } else if (c_bit & c_array) {
-                       duk_uint_fast32_t arr_len;
-                       duk_uint_fast32_t asize;
-
-                       DUK__EMIT_1(js_ctx, DUK_ASC_LBRACKET);
-
-                       /* Assume arrays are dense in the fast path. */
-                       if (!DUK_HOBJECT_HAS_ARRAY_PART(obj)) {
-                               DUK_DD(DUK_DDPRINT("Array object is sparse, abort fast path"));
-                               goto abort_fastpath;
-                       }
-
-                       arr_len = (duk_uint_fast32_t) duk_hobject_get_length(js_ctx->thr, obj);
-                       asize = (duk_uint_fast32_t) DUK_HOBJECT_GET_ASIZE(obj);
-                       if (arr_len > asize) {
-                               /* Array length is larger than 'asize'.  This shouldn't
-                                * happen in practice.  Bail out just in case.
-                                */
-                               DUK_DD(DUK_DDPRINT("arr_len > asize, abort fast path"));
-                               goto abort_fastpath;
-                       }
-                       /* Array part may be larger than 'length'; if so, iterate
-                        * only up to array 'length'.
-                        */
-                       for (i = 0; i < arr_len; i++) {
-                               DUK_ASSERT(i < (duk_uint_fast32_t) DUK_HOBJECT_GET_ASIZE(obj));
-
-                               tv_val = DUK_HOBJECT_A_GET_VALUE_PTR(js_ctx->thr->heap, obj, i);
-
-                               if (DUK_UNLIKELY(js_ctx->h_gap != NULL)) {
-                                       duk__enc_newline_indent(js_ctx, js_ctx->recursion_depth);
-                               }
-
-                               if (DUK_UNLIKELY(DUK_TVAL_IS_UNUSED(tv_val))) {
-                                       /* Gap in array; check for inherited property,
-                                        * bail out if one exists.  This should be enough
-                                        * to support gappy arrays for all practical code.
-                                        */
-                                       duk_hstring *h_tmp;
-                                       duk_bool_t has_inherited;
-
-                                       /* XXX: refactor into an internal helper, pretty awkward */
-                                       duk_push_uint((duk_context *) js_ctx->thr, (duk_uint_t) i);
-                                       h_tmp = duk_to_hstring((duk_context *) js_ctx->thr, -1);
-                                       DUK_ASSERT(h_tmp != NULL);
-                                       has_inherited = duk_hobject_hasprop_raw(js_ctx->thr, obj, h_tmp);
-                                       duk_pop((duk_context *) js_ctx->thr);
-
-                                       if (has_inherited) {
-                                               DUK_D(DUK_DPRINT("gap in array, conflicting inherited property, abort fast path"));
-                                               goto abort_fastpath;
-                                       }
-
-                                       /* Ordinary gap, undefined encodes to 'null' in
-                                        * standard JSON (and no JX/JC support here now).
-                                        */
-                                       DUK_D(DUK_DPRINT("gap in array, no conflicting inherited property, remain on fast path"));
-#if defined(DUK_USE_JX)
-                                       DUK__EMIT_STRIDX(js_ctx, js_ctx->stridx_custom_undefined);
-#else
-                                       DUK__EMIT_STRIDX(js_ctx, DUK_STRIDX_LC_NULL);
-#endif
-                               } else {
-                                       if (duk__json_stringify_fast_value(js_ctx, tv_val) == 0) {
-                                               DUK__EMIT_STRIDX(js_ctx, DUK_STRIDX_LC_NULL);
-                                       }
-                               }
-
-                               DUK__EMIT_1(js_ctx, DUK_ASC_COMMA);
-                               emitted = 1;
-                       }
-
-                       if (emitted) {
-                               DUK_ASSERT(*((duk_uint8_t *) DUK_BW_GET_PTR(js_ctx->thr, &js_ctx->bw) - 1) == DUK_ASC_COMMA);
-                               DUK__UNEMIT_1(js_ctx);  /* eat trailing comma */
-                               if (DUK_UNLIKELY(js_ctx->h_gap != NULL)) {
-                                       DUK_ASSERT(js_ctx->recursion_depth >= 1);
-                                       duk__enc_newline_indent(js_ctx, js_ctx->recursion_depth - 1);
-                               }
-                       }
-                       DUK__EMIT_1(js_ctx, DUK_ASC_RBRACKET);
-               } else if (c_bit & c_unbox) {
-                       /* Certain boxed types are required to go through
-                        * automatic unboxing.  Rely on internal value being
-                        * sane (to avoid infinite recursion).
-                        */
-#if 1
-                       /* The code below is incorrect if .toString() or .valueOf() have
-                        * have been overridden.  The correct approach would be to look up
-                        * the method(s) and if they resolve to the built-in function we
-                        * can safely bypass it and look up the internal value directly.
-                        * Unimplemented for now, abort fast path for boxed values.
-                        */
-                       goto abort_fastpath;
-#else  /* disabled */
-                       /* Disabled until fixed, see above. */
-                       duk_tval *tv_internal;
-
-                       DUK_DD(DUK_DDPRINT("auto unboxing in fast path"));
-
-                       tv_internal = duk_hobject_get_internal_value_tval_ptr(js_ctx->thr->heap, obj);
-                       DUK_ASSERT(tv_internal != NULL);
-                       DUK_ASSERT(DUK_TVAL_IS_STRING(tv_internal) ||
-                                  DUK_TVAL_IS_NUMBER(tv_internal) ||
-                                  DUK_TVAL_IS_BOOLEAN(tv_internal) ||
-                                  DUK_TVAL_IS_POINTER(tv_internal));
-
-                       tv = tv_internal;
-                       DUK_ASSERT(js_ctx->recursion_depth > 0);
-                       js_ctx->recursion_depth--;  /* required to keep recursion depth correct */
-                       goto restart_match;
-#endif  /* disabled */
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-               } else if (c_bit & c_func) {
-                       DUK__EMIT_STRIDX(js_ctx, js_ctx->stridx_custom_function);
-               } else if (c_bit & c_bufobj) {
-                       duk__enc_bufferobject(js_ctx, (duk_hbufferobject *) obj);
-#endif
-               } else {
-                       DUK_ASSERT((c_bit & c_undef) != 0);
-
-                       /* Must decrease recursion depth before returning. */
-                       DUK_ASSERT(js_ctx->recursion_depth > 0);
-                       DUK_ASSERT(js_ctx->recursion_depth <= js_ctx->recursion_limit);
-                       js_ctx->recursion_depth--;
-                       goto emit_undefined;
-               }
-
-               DUK_ASSERT(js_ctx->recursion_depth > 0);
-               DUK_ASSERT(js_ctx->recursion_depth <= js_ctx->recursion_limit);
-               js_ctx->recursion_depth--;
-               break;
-       }
-       case DUK_TAG_BUFFER: {
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-               if (js_ctx->flag_ext_custom_or_compatible) {
-                       duk__enc_buffer(js_ctx, DUK_TVAL_GET_BUFFER(tv));
-                       break;
-               } else {
-                       goto emit_undefined;
-               }
-#else
-               goto emit_undefined;
-#endif
-       }
-       case DUK_TAG_POINTER: {
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-               if (js_ctx->flag_ext_custom_or_compatible) {
-                       duk__enc_pointer(js_ctx, DUK_TVAL_GET_POINTER(tv));
-                       break;
-               } else {
-                       goto emit_undefined;
-               }
-#else
-               goto emit_undefined;
-#endif
-       }
-       case DUK_TAG_LIGHTFUNC: {
-               /* A lightfunc might also inherit a .toJSON() so just bail out. */
-               /* XXX: Could just lookup .toJSON() and continue in fast path,
-                * as it would almost never be defined.
-                */
-               DUK_DD(DUK_DDPRINT("value is a lightfunc, abort fast path"));
-               goto abort_fastpath;
-       }
-#if defined(DUK_USE_FASTINT)
-       case DUK_TAG_FASTINT: {
-               /* Number serialization has a significant impact relative to
-                * other fast path code, so careful fast path for fastints.
-                */
-               duk__enc_fastint_tval(js_ctx, tv);
-               break;
-       }
-#endif
-       default: {
-               /* XXX: A fast path for usual integers would be useful when
-                * fastint support is not enabled.
-                */
-               DUK_ASSERT(!DUK_TVAL_IS_UNUSED(tv));
-               DUK_ASSERT(DUK_TVAL_IS_NUMBER(tv));
-
-               /* XXX: Stack discipline is annoying, could be changed in numconv. */
-               duk_push_tval((duk_context *) js_ctx->thr, tv);
-               duk__enc_double(js_ctx);
-               duk_pop((duk_context *) js_ctx->thr);
-
-#if 0
-               /* Could also rely on native sprintf(), but it will handle
-                * values like NaN, Infinity, -0, exponent notation etc in
-                * a JSON-incompatible way.
-                */
-               duk_double_t d;
-               char buf[64];
-
-               DUK_ASSERT(DUK_TVAL_IS_DOUBLE(tv));
-               d = DUK_TVAL_GET_DOUBLE(tv);
-               DUK_SPRINTF(buf, "%lg", d);
-               DUK__EMIT_CSTR(js_ctx, buf);
-#endif
-       }
-       }
-       return 1;  /* not undefined */
-
- emit_undefined:
-       return 0;  /* value was undefined/unsupported */
-
- abort_fastpath:
-       /* Error message doesn't matter: the error is ignored anyway. */
-       DUK_DD(DUK_DDPRINT("aborting fast path"));
-       DUK_ERROR_INTERNAL_DEFMSG(js_ctx->thr);
-       return 0;  /* unreachable */
-}
-
-DUK_LOCAL duk_ret_t duk__json_stringify_fast(duk_context *ctx) {
-       duk_json_enc_ctx *js_ctx;
-       duk_tval *tv;
-
-       DUK_ASSERT(ctx != NULL);
-       tv = DUK_GET_TVAL_NEGIDX(ctx, -2);
-       DUK_ASSERT(DUK_TVAL_IS_POINTER(tv));
-       js_ctx = (duk_json_enc_ctx *) DUK_TVAL_GET_POINTER(tv);
-       DUK_ASSERT(js_ctx != NULL);
-
-       tv = DUK_GET_TVAL_NEGIDX(ctx, -1);
-       if (duk__json_stringify_fast_value(js_ctx, tv) == 0) {
-               DUK_DD(DUK_DDPRINT("top level value not supported, fail fast path"));
-               return DUK_RET_ERROR;  /* error message doesn't matter, ignored anyway */
-       }
-
-       return 0;
-}
-#endif  /* DUK_USE_JSON_STRINGIFY_FASTPATH */
-
-/*
- *  Top level wrappers
- */
-
-DUK_INTERNAL
-void duk_bi_json_parse_helper(duk_context *ctx,
-                              duk_idx_t idx_value,
-                              duk_idx_t idx_reviver,
-                              duk_small_uint_t flags) {
-       duk_hthread *thr = (duk_hthread *) ctx;
-       duk_json_dec_ctx js_ctx_alloc;
-       duk_json_dec_ctx *js_ctx = &js_ctx_alloc;
-       duk_hstring *h_text;
-#ifdef DUK_USE_ASSERTIONS
-       duk_idx_t entry_top = duk_get_top(ctx);
-#endif
-
-       /* negative top-relative indices not allowed now */
-       DUK_ASSERT(idx_value == DUK_INVALID_INDEX || idx_value >= 0);
-       DUK_ASSERT(idx_reviver == DUK_INVALID_INDEX || idx_reviver >= 0);
-
-       DUK_DDD(DUK_DDDPRINT("JSON parse start: text=%!T, reviver=%!T, flags=0x%08lx, stack_top=%ld",
-                            (duk_tval *) duk_get_tval(ctx, idx_value),
-                            (duk_tval *) duk_get_tval(ctx, idx_reviver),
-                            (unsigned long) flags,
-                            (long) duk_get_top(ctx)));
-
-       DUK_MEMZERO(&js_ctx_alloc, sizeof(js_ctx_alloc));
-       js_ctx->thr = thr;
-#ifdef DUK_USE_EXPLICIT_NULL_INIT
-       /* nothing now */
-#endif
-       js_ctx->recursion_limit = DUK_USE_JSON_DEC_RECLIMIT;
-       DUK_ASSERT(js_ctx->recursion_depth == 0);
-
-       /* Flag handling currently assumes that flags are consistent.  This is OK
-        * because the call sites are now strictly controlled.
-        */
-
-       js_ctx->flags = flags;
-#if defined(DUK_USE_JX)
-       js_ctx->flag_ext_custom = flags & DUK_JSON_FLAG_EXT_CUSTOM;
-#endif
-#if defined(DUK_USE_JC)
-       js_ctx->flag_ext_compatible = flags & DUK_JSON_FLAG_EXT_COMPATIBLE;
-#endif
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-       js_ctx->flag_ext_custom_or_compatible = flags & (DUK_JSON_FLAG_EXT_CUSTOM | DUK_JSON_FLAG_EXT_COMPATIBLE);
-#endif
-
-       h_text = duk_to_hstring(ctx, idx_value);  /* coerce in-place */
-       DUK_ASSERT(h_text != NULL);
-
-       /* JSON parsing code is allowed to read [p_start,p_end]: p_end is
-        * valid and points to the string NUL terminator (which is always
-        * guaranteed for duk_hstrings.
-        */
-       js_ctx->p_start = (const duk_uint8_t *) DUK_HSTRING_GET_DATA(h_text);
-       js_ctx->p = js_ctx->p_start;
-       js_ctx->p_end = ((const duk_uint8_t *) DUK_HSTRING_GET_DATA(h_text)) +
-                       DUK_HSTRING_GET_BYTELEN(h_text);
-       DUK_ASSERT(*(js_ctx->p_end) == 0x00);
-
-       duk__dec_value(js_ctx);  /* -> [ ... value ] */
-
-       /* Trailing whitespace has been eaten by duk__dec_value(), so if
-        * we're not at end of input here, it's a SyntaxError.
-        */
-
-       if (js_ctx->p != js_ctx->p_end) {
-               duk__dec_syntax_error(js_ctx);
-       }
-
-       if (duk_is_callable(ctx, idx_reviver)) {
-               DUK_DDD(DUK_DDDPRINT("applying reviver: %!T",
-                                    (duk_tval *) duk_get_tval(ctx, idx_reviver)));
-
-               js_ctx->idx_reviver = idx_reviver;
-
-               duk_push_object(ctx);
-               duk_dup(ctx, -2);  /* -> [ ... val root val ] */
-               duk_put_prop_stridx(ctx, -2, DUK_STRIDX_EMPTY_STRING);  /* default attrs ok */
-               duk_push_hstring_stridx(ctx, DUK_STRIDX_EMPTY_STRING);  /* -> [ ... val root "" ] */
-
-               DUK_DDD(DUK_DDDPRINT("start reviver walk, root=%!T, name=%!T",
-                                    (duk_tval *) duk_get_tval(ctx, -2),
-                                    (duk_tval *) duk_get_tval(ctx, -1)));
-
-               duk__dec_reviver_walk(js_ctx);  /* [ ... val root "" ] -> [ ... val val' ] */
-               duk_remove(ctx, -2);            /* -> [ ... val' ] */
-       } else {
-               DUK_DDD(DUK_DDDPRINT("reviver does not exist or is not callable: %!T",
-                                    (duk_tval *) duk_get_tval(ctx, idx_reviver)));
-       }
-
-       /* Final result is at stack top. */
-
-       DUK_DDD(DUK_DDDPRINT("JSON parse end: text=%!T, reviver=%!T, flags=0x%08lx, result=%!T, stack_top=%ld",
-                            (duk_tval *) duk_get_tval(ctx, idx_value),
-                            (duk_tval *) duk_get_tval(ctx, idx_reviver),
-                            (unsigned long) flags,
-                            (duk_tval *) duk_get_tval(ctx, -1),
-                            (long) duk_get_top(ctx)));
-
-       DUK_ASSERT(duk_get_top(ctx) == entry_top + 1);
-}
-
-DUK_INTERNAL
-void duk_bi_json_stringify_helper(duk_context *ctx,
-                                  duk_idx_t idx_value,
-                                  duk_idx_t idx_replacer,
-                                  duk_idx_t idx_space,
-                                  duk_small_uint_t flags) {
-       duk_hthread *thr = (duk_hthread *) ctx;
-       duk_json_enc_ctx js_ctx_alloc;
-       duk_json_enc_ctx *js_ctx = &js_ctx_alloc;
-       duk_hobject *h;
-       duk_idx_t idx_holder;
-       duk_idx_t entry_top;
-
-       /* negative top-relative indices not allowed now */
-       DUK_ASSERT(idx_value == DUK_INVALID_INDEX || idx_value >= 0);
-       DUK_ASSERT(idx_replacer == DUK_INVALID_INDEX || idx_replacer >= 0);
-       DUK_ASSERT(idx_space == DUK_INVALID_INDEX || idx_space >= 0);
-
-       DUK_DDD(DUK_DDDPRINT("JSON stringify start: value=%!T, replacer=%!T, space=%!T, flags=0x%08lx, stack_top=%ld",
-                            (duk_tval *) duk_get_tval(ctx, idx_value),
-                            (duk_tval *) duk_get_tval(ctx, idx_replacer),
-                            (duk_tval *) duk_get_tval(ctx, idx_space),
-                            (unsigned long) flags,
-                            (long) duk_get_top(ctx)));
-
-       entry_top = duk_get_top(ctx);
-
-       /*
-        *  Context init
-        */
-
-       DUK_MEMZERO(&js_ctx_alloc, sizeof(js_ctx_alloc));
-       js_ctx->thr = thr;
-#ifdef DUK_USE_EXPLICIT_NULL_INIT
-       js_ctx->h_replacer = NULL;
-       js_ctx->h_gap = NULL;
-#endif
-       js_ctx->idx_proplist = -1;
-
-       /* Flag handling currently assumes that flags are consistent.  This is OK
-        * because the call sites are now strictly controlled.
-        */
-
-       js_ctx->flags = flags;
-       js_ctx->flag_ascii_only = flags & DUK_JSON_FLAG_ASCII_ONLY;
-       js_ctx->flag_avoid_key_quotes = flags & DUK_JSON_FLAG_AVOID_KEY_QUOTES;
-#ifdef DUK_USE_JX
-       js_ctx->flag_ext_custom = flags & DUK_JSON_FLAG_EXT_CUSTOM;
-#endif
-#ifdef DUK_USE_JC
-       js_ctx->flag_ext_compatible = flags & DUK_JSON_FLAG_EXT_COMPATIBLE;
-#endif
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-       js_ctx->flag_ext_custom_or_compatible = flags & (DUK_JSON_FLAG_EXT_CUSTOM | DUK_JSON_FLAG_EXT_COMPATIBLE);
-#endif
-
-       /* The #ifdef clutter here handles the JX/JC enable/disable
-        * combinations properly.
-        */
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-       js_ctx->stridx_custom_undefined = DUK_STRIDX_LC_NULL;  /* standard JSON; array gaps */
-#if defined(DUK_USE_JX)
-       if (flags & DUK_JSON_FLAG_EXT_CUSTOM) {
-               js_ctx->stridx_custom_undefined = DUK_STRIDX_LC_UNDEFINED;
-               js_ctx->stridx_custom_nan = DUK_STRIDX_NAN;
-               js_ctx->stridx_custom_neginf = DUK_STRIDX_MINUS_INFINITY;
-               js_ctx->stridx_custom_posinf = DUK_STRIDX_INFINITY;
-               js_ctx->stridx_custom_function =
-                       (flags & DUK_JSON_FLAG_AVOID_KEY_QUOTES) ?
-                               DUK_STRIDX_JSON_EXT_FUNCTION2 :
-                               DUK_STRIDX_JSON_EXT_FUNCTION1;
-       }
-#endif  /* DUK_USE_JX */
-#if defined(DUK_USE_JX) && defined(DUK_USE_JC)
-       else
-#endif  /* DUK_USE_JX && DUK_USE_JC */
-#if defined(DUK_USE_JC)
-       if (js_ctx->flags & DUK_JSON_FLAG_EXT_COMPATIBLE) {
-               js_ctx->stridx_custom_undefined = DUK_STRIDX_JSON_EXT_UNDEFINED;
-               js_ctx->stridx_custom_nan = DUK_STRIDX_JSON_EXT_NAN;
-               js_ctx->stridx_custom_neginf = DUK_STRIDX_JSON_EXT_NEGINF;
-               js_ctx->stridx_custom_posinf = DUK_STRIDX_JSON_EXT_POSINF;
-               js_ctx->stridx_custom_function = DUK_STRIDX_JSON_EXT_FUNCTION1;
-       }
-#endif  /* DUK_USE_JC */
-#endif  /* DUK_USE_JX || DUK_USE_JC */
-
-#if defined(DUK_USE_JX) || defined(DUK_USE_JC)
-       if (js_ctx->flags & (DUK_JSON_FLAG_EXT_CUSTOM |
-                            DUK_JSON_FLAG_EXT_COMPATIBLE)) {
-               DUK_ASSERT(js_ctx->mask_for_undefined == 0);  /* already zero */
-       }
-       else
-#endif  /* DUK_USE_JX || DUK_USE_JC */
-       {
-               js_ctx->mask_for_undefined = DUK_TYPE_MASK_UNDEFINED |
-                                            DUK_TYPE_MASK_POINTER |
-                                            DUK_TYPE_MASK_BUFFER |
-                                            DUK_TYPE_MASK_LIGHTFUNC;
-       }
-
-       DUK_BW_INIT_PUSHBUF(thr, &js_ctx->bw, DUK__JSON_STRINGIFY_BUFSIZE);
-
-       js_ctx->idx_loop = duk_push_object_internal(ctx);
-       DUK_ASSERT(js_ctx->idx_loop >= 0);
-
-       /* [ ... buf loop ] */
-
-       /*
-        *  Process replacer/proplist (2nd argument to JSON.stringify)
-        */
-
-       h = duk_get_hobject(ctx, idx_replacer);
-       if (h != NULL) {
-               if (DUK_HOBJECT_IS_CALLABLE(h)) {
-                       js_ctx->h_replacer = h;
-               } else if (DUK_HOBJECT_GET_CLASS_NUMBER(h) == DUK_HOBJECT_CLASS_ARRAY) {
-                       /* Here the specification requires correct array index enumeration
-                        * which is a bit tricky for sparse arrays (it is handled by the
-                        * enum setup code).  We now enumerate ancestors too, although the
-                        * specification is not very clear on whether that is required.
-                        */
-
-                       duk_uarridx_t plist_idx = 0;
-                       duk_small_uint_t enum_flags;
-
-                       js_ctx->idx_proplist = duk_push_array(ctx);  /* XXX: array internal? */
-
-                       enum_flags = DUK_ENUM_ARRAY_INDICES_ONLY |
-                                    DUK_ENUM_SORT_ARRAY_INDICES;  /* expensive flag */
-                       duk_enum(ctx, idx_replacer, enum_flags);
-                       while (duk_next(ctx, -1 /*enum_index*/, 1 /*get_value*/)) {
-                               /* [ ... proplist enum_obj key val ] */
-                               if (duk__enc_allow_into_proplist(duk_get_tval(ctx, -1))) {
-                                       /* XXX: duplicates should be eliminated here */
-                                       DUK_DDD(DUK_DDDPRINT("proplist enum: key=%!T, val=%!T --> accept",
-                                                            (duk_tval *) duk_get_tval(ctx, -2),
-                                                            (duk_tval *) duk_get_tval(ctx, -1)));
-                                       duk_to_string(ctx, -1);  /* extra coercion of strings is OK */
-                                       duk_put_prop_index(ctx, -4, plist_idx);  /* -> [ ... proplist enum_obj key ] */
-                                       plist_idx++;
-                                       duk_pop(ctx);
-                               } else {
-                                       DUK_DDD(DUK_DDDPRINT("proplist enum: key=%!T, val=%!T --> reject",
-                                                            (duk_tval *) duk_get_tval(ctx, -2),
-                                                            (duk_tval *) duk_get_tval(ctx, -1)));
-                                       duk_pop_2(ctx);
-                               }
-                        }
-                        duk_pop(ctx);  /* pop enum */
-
-                       /* [ ... proplist ] */
-               }
-       }
-
-       /* [ ... buf loop (proplist) ] */
-
-       /*
-        *  Process space (3rd argument to JSON.stringify)
-        */
-
-       h = duk_get_hobject(ctx, idx_space);
-       if (h != NULL) {
-               int c = DUK_HOBJECT_GET_CLASS_NUMBER(h);
-               if (c == DUK_HOBJECT_CLASS_NUMBER) {
-                       duk_to_number(ctx, idx_space);
-               } else if (c == DUK_HOBJECT_CLASS_STRING) {
-                       duk_to_string(ctx, idx_space);
-               }
-       }
-
-       if (duk_is_number(ctx, idx_space)) {
-               duk_small_int_t nspace;
-               /* spaces[] must be static to allow initializer with old compilers like BCC */
-               static const char spaces[10] = {
-                       DUK_ASC_SPACE, DUK_ASC_SPACE, DUK_ASC_SPACE, DUK_ASC_SPACE,
-                       DUK_ASC_SPACE, DUK_ASC_SPACE, DUK_ASC_SPACE, DUK_ASC_SPACE,
-                       DUK_ASC_SPACE, DUK_ASC_SPACE
-               };  /* XXX: helper */
-
-               /* ToInteger() coercion; NaN -> 0, infinities are clamped to 0 and 10 */
-               nspace = (duk_small_int_t) duk_to_int_clamped(ctx, idx_space, 0 /*minval*/, 10 /*maxval*/);
-               DUK_ASSERT(nspace >= 0 && nspace <= 10);
-
-               duk_push_lstring(ctx, spaces, (duk_size_t) nspace);
-               js_ctx->h_gap = duk_get_hstring(ctx, -1);
-               DUK_ASSERT(js_ctx->h_gap != NULL);
-       } else if (duk_is_string(ctx, idx_space)) {
-               /* XXX: substring in-place at idx_place? */
-               duk_dup(ctx, idx_space);
-               duk_substring(ctx, -1, 0, 10);  /* clamp to 10 chars */
-               js_ctx->h_gap = duk_get_hstring(ctx, -1);
-               DUK_ASSERT(js_ctx->h_gap != NULL);
-       } else {
-               /* nop */
-       }
-
-       if (js_ctx->h_gap != NULL) {
-               /* if gap is empty, behave as if not given at all */
-               if (DUK_HSTRING_GET_CHARLEN(js_ctx->h_gap) == 0) {
-                       js_ctx->h_gap = NULL;
-               }
-       }
-
-       /* [ ... buf loop (proplist) (gap) ] */
-
-       /*
-        *  Fast path: assume no mutation, iterate object property tables
-        *  directly; bail out if that assumption doesn't hold.
-        */
-
-#if defined(DUK_USE_JSON_STRINGIFY_FASTPATH)
-       if (js_ctx->h_replacer == NULL &&  /* replacer is a mutation risk */
-           js_ctx->idx_proplist == -1) {  /* proplist is very rare */
-               duk_int_t pcall_rc;
-#ifdef DUK_USE_MARK_AND_SWEEP
-               duk_small_uint_t prev_mark_and_sweep_base_flags;
-#endif
-
-               DUK_DD(DUK_DDPRINT("try JSON.stringify() fast path"));
-
-               /* Use recursion_limit to ensure we don't overwrite js_ctx->visiting[]
-                * array so we don't need two counter checks in the fast path.  The
-                * slow path has a much larger recursion limit which we'll use if
-                * necessary.
-                */
-               DUK_ASSERT(DUK_USE_JSON_ENC_RECLIMIT >= DUK_JSON_ENC_LOOPARRAY);
-               js_ctx->recursion_limit = DUK_JSON_ENC_LOOPARRAY;
-               DUK_ASSERT(js_ctx->recursion_depth == 0);
-
-               /* Execute the fast path in a protected call.  If any error is thrown,
-                * fall back to the slow path.  This includes e.g. recursion limit
-                * because the fast path has a smaller recursion limit (and simpler,
-                * limited loop detection).
-                */
-
-               duk_push_pointer(ctx, (void *) js_ctx);
-               duk_dup(ctx, idx_value);
-
-#if defined(DUK_USE_MARK_AND_SWEEP)
-               /* Must prevent finalizers which may have arbitrary side effects. */
-               prev_mark_and_sweep_base_flags = thr->heap->mark_and_sweep_base_flags;
-               thr->heap->mark_and_sweep_base_flags |=
-                       DUK_MS_FLAG_NO_FINALIZERS |         /* avoid attempts to add/remove object keys */
-                       DUK_MS_FLAG_NO_OBJECT_COMPACTION;   /* avoid attempt to compact any objects */
-#endif
-
-               pcall_rc = duk_safe_call(ctx, duk__json_stringify_fast, 2 /*nargs*/, 0 /*nret*/);
-
-#if defined(DUK_USE_MARK_AND_SWEEP)
-               thr->heap->mark_and_sweep_base_flags = prev_mark_and_sweep_base_flags;
-#endif
-               if (pcall_rc == DUK_EXEC_SUCCESS) {
-                       DUK_DD(DUK_DDPRINT("fast path successful"));
-                       DUK_BW_PUSH_AS_STRING(thr, &js_ctx->bw);
-                       goto replace_finished;
-               }
-
-               /* We come here for actual aborts (like encountering .toJSON())
-                * but also for recursion/loop errors.  Bufwriter size can be
-                * kept because we'll probably need at least as much as we've
-                * allocated so far.
-                */
-               DUK_D(DUK_DPRINT("fast path failed, serialize using slow path instead"));
-               DUK_BW_RESET_SIZE(thr, &js_ctx->bw);
-               js_ctx->recursion_depth = 0;
-       }
-#endif
-
-       /*
-        *  Create wrapper object and serialize
-        */
-
-       idx_holder = duk_push_object(ctx);
-       duk_dup(ctx, idx_value);
-       duk_put_prop_stridx(ctx, -2, DUK_STRIDX_EMPTY_STRING);
-
-       DUK_DDD(DUK_DDDPRINT("before: flags=0x%08lx, loop=%!T, replacer=%!O, "
-                            "proplist=%!T, gap=%!O, holder=%!T",
-                            (unsigned long) js_ctx->flags,
-                            (duk_tval *) duk_get_tval(ctx, js_ctx->idx_loop),
-                            (duk_heaphdr *) js_ctx->h_replacer,
-                            (duk_tval *) (js_ctx->idx_proplist >= 0 ? duk_get_tval(ctx, js_ctx->idx_proplist) : NULL),
-                            (duk_heaphdr *) js_ctx->h_gap,
-                            (duk_tval *) duk_get_tval(ctx, -1)));
-
-       /* serialize the wrapper with empty string key */
-
-       duk_push_hstring_stridx(ctx, DUK_STRIDX_EMPTY_STRING);
-
-       /* [ ... buf loop (proplist) (gap) holder "" ] */
-
-       js_ctx->recursion_limit = DUK_USE_JSON_ENC_RECLIMIT;
-       DUK_ASSERT(js_ctx->recursion_depth == 0);
-
-       if (DUK_UNLIKELY(duk__enc_value(js_ctx, idx_holder) == 0)) {  /* [ ... holder key ] -> [ ... holder ] */
-               /* Result is undefined. */
-               duk_push_undefined(ctx);
-       } else {
-               /* Convert buffer to result string. */
-               DUK_BW_PUSH_AS_STRING(thr, &js_ctx->bw);
-       }
-
-       DUK_DDD(DUK_DDDPRINT("after: flags=0x%08lx, loop=%!T, replacer=%!O, "
-                            "proplist=%!T, gap=%!O, holder=%!T",
-                            (unsigned long) js_ctx->flags,
-                            (duk_tval *) duk_get_tval(ctx, js_ctx->idx_loop),
-                            (duk_heaphdr *) js_ctx->h_replacer,
-                            (duk_tval *) (js_ctx->idx_proplist >= 0 ? duk_get_tval(ctx, js_ctx->idx_proplist) : NULL),
-                            (duk_heaphdr *) js_ctx->h_gap,
-                            (duk_tval *) duk_get_tval(ctx, idx_holder)));
-
-       /* The stack has a variable shape here, so force it to the
-        * desired one explicitly.
-        */
-
-#if defined(DUK_USE_JSON_STRINGIFY_FASTPATH)
- replace_finished:
-#endif
-       duk_replace(ctx, entry_top);
-       duk_set_top(ctx, entry_top + 1);
-
-       DUK_DDD(DUK_DDDPRINT("JSON stringify end: value=%!T, replacer=%!T, space=%!T, "
-                            "flags=0x%08lx, result=%!T, stack_top=%ld",
-                            (duk_tval *) duk_get_tval(ctx, idx_value),
-                            (duk_tval *) duk_get_tval(ctx, idx_replacer),
-                            (duk_tval *) duk_get_tval(ctx, idx_space),
-                            (unsigned long) flags,
-                            (duk_tval *) duk_get_tval(ctx, -1),
-                            (long) duk_get_top(ctx)));
-
-       DUK_ASSERT(duk_get_top(ctx) == entry_top + 1);
-}
-
-/*
- *  Entry points
- */
-
-DUK_INTERNAL duk_ret_t duk_bi_json_object_parse(duk_context *ctx) {
-       duk_bi_json_parse_helper(ctx,
-                                0 /*idx_value*/,
-                                1 /*idx_replacer*/,
-                                0 /*flags*/);
-       return 1;
-}
-
-DUK_INTERNAL duk_ret_t duk_bi_json_object_stringify(duk_context *ctx) {
-       duk_bi_json_stringify_helper(ctx,
-                                    0 /*idx_value*/,
-                                    1 /*idx_replacer*/,
-                                    2 /*idx_space*/,
-                                    0 /*flags*/);
-       return 1;
-}
-
-#undef DUK__JSON_DECSTR_BUFSIZE
-#undef DUK__JSON_DECSTR_CHUNKSIZE
-#undef DUK__JSON_ENCSTR_CHUNKSIZE
-#undef DUK__JSON_STRINGIFY_BUFSIZE
-#undef DUK__JSON_MAX_ESC_LEN