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9346a6ac | 1 | // Copyright 2013-2015 The Rust Project Developers. See the COPYRIGHT |
1a4d82fc JJ |
2 | // file at the top-level directory of this distribution and at |
3 | // http://rust-lang.org/COPYRIGHT. | |
4 | // | |
5 | // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or | |
6 | // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license | |
7 | // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your | |
8 | // option. This file may not be copied, modified, or distributed | |
9 | // except according to those terms. | |
10 | ||
54a0048b | 11 | //! Utilities for formatting and printing strings. |
1a4d82fc | 12 | |
85aaf69f | 13 | #![stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 14 | |
e9174d1e | 15 | use prelude::v1::*; |
9346a6ac | 16 | |
54a0048b | 17 | use cell::{UnsafeCell, Cell, RefCell, Ref, RefMut, BorrowState}; |
9346a6ac | 18 | use marker::PhantomData; |
1a4d82fc | 19 | use mem; |
d9579d0f | 20 | use num::flt2dec; |
9346a6ac | 21 | use ops::Deref; |
1a4d82fc | 22 | use result; |
1a4d82fc | 23 | use slice; |
9346a6ac | 24 | use str; |
54a0048b SL |
25 | |
26 | #[unstable(feature = "fmt_flags_align", issue = "27726")] | |
27 | /// Possible alignments returned by `Formatter::align` | |
28 | #[derive(Debug)] | |
29 | pub enum Alignment { | |
30 | /// Indication that contents should be left-aligned. | |
31 | Left, | |
32 | /// Indication that contents should be right-aligned. | |
33 | Right, | |
34 | /// Indication that contents should be center-aligned. | |
35 | Center, | |
36 | /// No alignment was requested. | |
37 | Unknown, | |
38 | } | |
39 | ||
92a42be0 | 40 | #[stable(feature = "debug_builders", since = "1.2.0")] |
c34b1796 AL |
41 | pub use self::builders::{DebugStruct, DebugTuple, DebugSet, DebugList, DebugMap}; |
42 | ||
1a4d82fc | 43 | mod num; |
c34b1796 | 44 | mod builders; |
1a4d82fc | 45 | |
e9174d1e SL |
46 | #[unstable(feature = "fmt_internals", reason = "internal to format_args!", |
47 | issue = "0")] | |
85aaf69f SL |
48 | #[doc(hidden)] |
49 | pub mod rt { | |
50 | pub mod v1; | |
51 | } | |
52 | ||
53 | #[stable(feature = "rust1", since = "1.0.0")] | |
1a4d82fc JJ |
54 | /// The type returned by formatter methods. |
55 | pub type Result = result::Result<(), Error>; | |
56 | ||
57 | /// The error type which is returned from formatting a message into a stream. | |
58 | /// | |
59 | /// This type does not support transmission of an error other than that an error | |
60 | /// occurred. Any extra information must be arranged to be transmitted through | |
61 | /// some other means. | |
85aaf69f | 62 | #[stable(feature = "rust1", since = "1.0.0")] |
a7813a04 | 63 | #[derive(Copy, Clone, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)] |
1a4d82fc JJ |
64 | pub struct Error; |
65 | ||
66 | /// A collection of methods that are required to format a message into a stream. | |
67 | /// | |
68 | /// This trait is the type which this modules requires when formatting | |
85aaf69f | 69 | /// information. This is similar to the standard library's `io::Write` trait, |
1a4d82fc JJ |
70 | /// but it is only intended for use in libcore. |
71 | /// | |
72 | /// This trait should generally not be implemented by consumers of the standard | |
85aaf69f SL |
73 | /// library. The `write!` macro accepts an instance of `io::Write`, and the |
74 | /// `io::Write` trait is favored over implementing this trait. | |
75 | #[stable(feature = "rust1", since = "1.0.0")] | |
76 | pub trait Write { | |
1a4d82fc JJ |
77 | /// Writes a slice of bytes into this writer, returning whether the write |
78 | /// succeeded. | |
79 | /// | |
80 | /// This method can only succeed if the entire byte slice was successfully | |
81 | /// written, and this method will not return until all data has been | |
82 | /// written or an error occurs. | |
83 | /// | |
84 | /// # Errors | |
85 | /// | |
62682a34 | 86 | /// This function will return an instance of `Error` on error. |
85aaf69f | 87 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
88 | fn write_str(&mut self, s: &str) -> Result; |
89 | ||
d9579d0f AL |
90 | /// Writes a `char` into this writer, returning whether the write succeeded. |
91 | /// | |
92 | /// A single `char` may be encoded as more than one byte. | |
93 | /// This method can only succeed if the entire byte sequence was successfully | |
94 | /// written, and this method will not return until all data has been | |
95 | /// written or an error occurs. | |
96 | /// | |
97 | /// # Errors | |
98 | /// | |
62682a34 | 99 | /// This function will return an instance of `Error` on error. |
d9579d0f AL |
100 | #[stable(feature = "fmt_write_char", since = "1.1.0")] |
101 | fn write_char(&mut self, c: char) -> Result { | |
54a0048b SL |
102 | self.write_str(unsafe { |
103 | str::from_utf8_unchecked(c.encode_utf8().as_slice()) | |
104 | }) | |
d9579d0f AL |
105 | } |
106 | ||
b039eaaf | 107 | /// Glue for usage of the `write!` macro with implementors of this trait. |
1a4d82fc JJ |
108 | /// |
109 | /// This method should generally not be invoked manually, but rather through | |
110 | /// the `write!` macro itself. | |
85aaf69f | 111 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
112 | fn write_fmt(&mut self, args: Arguments) -> Result { |
113 | // This Adapter is needed to allow `self` (of type `&mut | |
85aaf69f | 114 | // Self`) to be cast to a Write (below) without |
1a4d82fc JJ |
115 | // requiring a `Sized` bound. |
116 | struct Adapter<'a,T: ?Sized +'a>(&'a mut T); | |
117 | ||
85aaf69f SL |
118 | impl<'a, T: ?Sized> Write for Adapter<'a, T> |
119 | where T: Write | |
1a4d82fc JJ |
120 | { |
121 | fn write_str(&mut self, s: &str) -> Result { | |
122 | self.0.write_str(s) | |
123 | } | |
124 | ||
7453a54e SL |
125 | fn write_char(&mut self, c: char) -> Result { |
126 | self.0.write_char(c) | |
127 | } | |
128 | ||
1a4d82fc JJ |
129 | fn write_fmt(&mut self, args: Arguments) -> Result { |
130 | self.0.write_fmt(args) | |
131 | } | |
132 | } | |
133 | ||
134 | write(&mut Adapter(self), args) | |
135 | } | |
136 | } | |
137 | ||
e9174d1e SL |
138 | #[stable(feature = "fmt_write_blanket_impl", since = "1.4.0")] |
139 | impl<'a, W: Write + ?Sized> Write for &'a mut W { | |
140 | fn write_str(&mut self, s: &str) -> Result { | |
141 | (**self).write_str(s) | |
142 | } | |
143 | ||
144 | fn write_char(&mut self, c: char) -> Result { | |
145 | (**self).write_char(c) | |
146 | } | |
147 | ||
148 | fn write_fmt(&mut self, args: Arguments) -> Result { | |
149 | (**self).write_fmt(args) | |
150 | } | |
151 | } | |
152 | ||
1a4d82fc JJ |
153 | /// A struct to represent both where to emit formatting strings to and how they |
154 | /// should be formatted. A mutable version of this is passed to all formatting | |
155 | /// traits. | |
54a0048b | 156 | #[allow(missing_debug_implementations)] |
85aaf69f | 157 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 158 | pub struct Formatter<'a> { |
c34b1796 | 159 | flags: u32, |
1a4d82fc | 160 | fill: char, |
85aaf69f | 161 | align: rt::v1::Alignment, |
c34b1796 AL |
162 | width: Option<usize>, |
163 | precision: Option<usize>, | |
1a4d82fc | 164 | |
85aaf69f SL |
165 | buf: &'a mut (Write+'a), |
166 | curarg: slice::Iter<'a, ArgumentV1<'a>>, | |
167 | args: &'a [ArgumentV1<'a>], | |
1a4d82fc JJ |
168 | } |
169 | ||
170 | // NB. Argument is essentially an optimized partially applied formatting function, | |
171 | // equivalent to `exists T.(&T, fn(&T, &mut Formatter) -> Result`. | |
172 | ||
173 | enum Void {} | |
174 | ||
175 | /// This struct represents the generic "argument" which is taken by the Xprintf | |
176 | /// family of functions. It contains a function to format the given value. At | |
177 | /// compile time it is ensured that the function and the value have the correct | |
178 | /// types, and then this struct is used to canonicalize arguments to one type. | |
1a4d82fc | 179 | #[derive(Copy)] |
54a0048b | 180 | #[allow(missing_debug_implementations)] |
e9174d1e SL |
181 | #[unstable(feature = "fmt_internals", reason = "internal to format_args!", |
182 | issue = "0")] | |
85aaf69f SL |
183 | #[doc(hidden)] |
184 | pub struct ArgumentV1<'a> { | |
1a4d82fc JJ |
185 | value: &'a Void, |
186 | formatter: fn(&Void, &mut Formatter) -> Result, | |
187 | } | |
188 | ||
92a42be0 SL |
189 | #[unstable(feature = "fmt_internals", reason = "internal to format_args!", |
190 | issue = "0")] | |
c34b1796 AL |
191 | impl<'a> Clone for ArgumentV1<'a> { |
192 | fn clone(&self) -> ArgumentV1<'a> { | |
193 | *self | |
194 | } | |
195 | } | |
196 | ||
85aaf69f | 197 | impl<'a> ArgumentV1<'a> { |
1a4d82fc | 198 | #[inline(never)] |
c34b1796 | 199 | fn show_usize(x: &usize, f: &mut Formatter) -> Result { |
85aaf69f | 200 | Display::fmt(x, f) |
1a4d82fc JJ |
201 | } |
202 | ||
85aaf69f | 203 | #[doc(hidden)] |
e9174d1e SL |
204 | #[unstable(feature = "fmt_internals", reason = "internal to format_args!", |
205 | issue = "0")] | |
85aaf69f SL |
206 | pub fn new<'b, T>(x: &'b T, |
207 | f: fn(&T, &mut Formatter) -> Result) -> ArgumentV1<'b> { | |
1a4d82fc | 208 | unsafe { |
85aaf69f | 209 | ArgumentV1 { |
1a4d82fc JJ |
210 | formatter: mem::transmute(f), |
211 | value: mem::transmute(x) | |
212 | } | |
213 | } | |
214 | } | |
215 | ||
85aaf69f | 216 | #[doc(hidden)] |
e9174d1e SL |
217 | #[unstable(feature = "fmt_internals", reason = "internal to format_args!", |
218 | issue = "0")] | |
c34b1796 AL |
219 | pub fn from_usize(x: &usize) -> ArgumentV1 { |
220 | ArgumentV1::new(x, ArgumentV1::show_usize) | |
1a4d82fc JJ |
221 | } |
222 | ||
c34b1796 AL |
223 | fn as_usize(&self) -> Option<usize> { |
224 | if self.formatter as usize == ArgumentV1::show_usize as usize { | |
225 | Some(unsafe { *(self.value as *const _ as *const usize) }) | |
1a4d82fc JJ |
226 | } else { |
227 | None | |
228 | } | |
229 | } | |
230 | } | |
231 | ||
85aaf69f | 232 | // flags available in the v1 format of format_args |
c34b1796 | 233 | #[derive(Copy, Clone)] |
85aaf69f SL |
234 | #[allow(dead_code)] // SignMinus isn't currently used |
235 | enum FlagV1 { SignPlus, SignMinus, Alternate, SignAwareZeroPad, } | |
236 | ||
1a4d82fc JJ |
237 | impl<'a> Arguments<'a> { |
238 | /// When using the format_args!() macro, this function is used to generate the | |
239 | /// Arguments structure. | |
240 | #[doc(hidden)] #[inline] | |
e9174d1e SL |
241 | #[unstable(feature = "fmt_internals", reason = "internal to format_args!", |
242 | issue = "0")] | |
85aaf69f SL |
243 | pub fn new_v1(pieces: &'a [&'a str], |
244 | args: &'a [ArgumentV1<'a>]) -> Arguments<'a> { | |
1a4d82fc JJ |
245 | Arguments { |
246 | pieces: pieces, | |
247 | fmt: None, | |
248 | args: args | |
249 | } | |
250 | } | |
251 | ||
252 | /// This function is used to specify nonstandard formatting parameters. | |
253 | /// The `pieces` array must be at least as long as `fmt` to construct | |
254 | /// a valid Arguments structure. Also, any `Count` within `fmt` that is | |
255 | /// `CountIsParam` or `CountIsNextParam` has to point to an argument | |
c34b1796 | 256 | /// created with `argumentusize`. However, failing to do so doesn't cause |
1a4d82fc JJ |
257 | /// unsafety, but will ignore invalid . |
258 | #[doc(hidden)] #[inline] | |
e9174d1e SL |
259 | #[unstable(feature = "fmt_internals", reason = "internal to format_args!", |
260 | issue = "0")] | |
85aaf69f SL |
261 | pub fn new_v1_formatted(pieces: &'a [&'a str], |
262 | args: &'a [ArgumentV1<'a>], | |
263 | fmt: &'a [rt::v1::Argument]) -> Arguments<'a> { | |
1a4d82fc JJ |
264 | Arguments { |
265 | pieces: pieces, | |
266 | fmt: Some(fmt), | |
267 | args: args | |
268 | } | |
269 | } | |
270 | } | |
271 | ||
272 | /// This structure represents a safely precompiled version of a format string | |
273 | /// and its arguments. This cannot be generated at runtime because it cannot | |
274 | /// safely be done so, so no constructors are given and the fields are private | |
275 | /// to prevent modification. | |
276 | /// | |
277 | /// The `format_args!` macro will safely create an instance of this structure | |
278 | /// and pass it to a function or closure, passed as the first argument. The | |
279 | /// macro validates the format string at compile-time so usage of the `write` | |
280 | /// and `format` functions can be safely performed. | |
85aaf69f | 281 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 282 | #[derive(Copy, Clone)] |
1a4d82fc JJ |
283 | pub struct Arguments<'a> { |
284 | // Format string pieces to print. | |
285 | pieces: &'a [&'a str], | |
286 | ||
287 | // Placeholder specs, or `None` if all specs are default (as in "{}{}"). | |
85aaf69f | 288 | fmt: Option<&'a [rt::v1::Argument]>, |
1a4d82fc JJ |
289 | |
290 | // Dynamic arguments for interpolation, to be interleaved with string | |
291 | // pieces. (Every argument is preceded by a string piece.) | |
85aaf69f | 292 | args: &'a [ArgumentV1<'a>], |
1a4d82fc JJ |
293 | } |
294 | ||
85aaf69f SL |
295 | #[stable(feature = "rust1", since = "1.0.0")] |
296 | impl<'a> Debug for Arguments<'a> { | |
1a4d82fc | 297 | fn fmt(&self, fmt: &mut Formatter) -> Result { |
85aaf69f | 298 | Display::fmt(self, fmt) |
1a4d82fc JJ |
299 | } |
300 | } | |
301 | ||
85aaf69f SL |
302 | #[stable(feature = "rust1", since = "1.0.0")] |
303 | impl<'a> Display for Arguments<'a> { | |
1a4d82fc JJ |
304 | fn fmt(&self, fmt: &mut Formatter) -> Result { |
305 | write(fmt.buf, *self) | |
306 | } | |
307 | } | |
308 | ||
c1a9b12d SL |
309 | /// Format trait for the `?` character. |
310 | /// | |
311 | /// `Debug` should format the output in a programmer-facing, debugging context. | |
62682a34 SL |
312 | /// |
313 | /// Generally speaking, you should just `derive` a `Debug` implementation. | |
314 | /// | |
c1a9b12d SL |
315 | /// When used with the alternate format specifier `#?`, the output is pretty-printed. |
316 | /// | |
317 | /// For more information on formatters, see [the module-level documentation][module]. | |
318 | /// | |
b039eaaf | 319 | /// [module]: ../../std/fmt/index.html |
c1a9b12d | 320 | /// |
3157f602 XL |
321 | /// This trait can be used with `#[derive]` if all fields implement `Debug`. When |
322 | /// `derive`d for structs, it will use the name of the `struct`, then `{`, then a | |
323 | /// comma-separated list of each field's name and `Debug` value, then `}`. For | |
324 | /// `enum`s, it will use the name of the variant and, if applicable, `(`, then the | |
325 | /// `Debug` values of the fields, then `)`. | |
92a42be0 | 326 | /// |
62682a34 SL |
327 | /// # Examples |
328 | /// | |
329 | /// Deriving an implementation: | |
330 | /// | |
331 | /// ``` | |
332 | /// #[derive(Debug)] | |
333 | /// struct Point { | |
334 | /// x: i32, | |
335 | /// y: i32, | |
336 | /// } | |
337 | /// | |
338 | /// let origin = Point { x: 0, y: 0 }; | |
339 | /// | |
340 | /// println!("The origin is: {:?}", origin); | |
341 | /// ``` | |
342 | /// | |
343 | /// Manually implementing: | |
344 | /// | |
345 | /// ``` | |
346 | /// use std::fmt; | |
347 | /// | |
348 | /// struct Point { | |
349 | /// x: i32, | |
350 | /// y: i32, | |
351 | /// } | |
352 | /// | |
353 | /// impl fmt::Debug for Point { | |
354 | /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
92a42be0 | 355 | /// write!(f, "Point {{ x: {}, y: {} }}", self.x, self.y) |
62682a34 SL |
356 | /// } |
357 | /// } | |
358 | /// | |
359 | /// let origin = Point { x: 0, y: 0 }; | |
360 | /// | |
361 | /// println!("The origin is: {:?}", origin); | |
362 | /// ``` | |
363 | /// | |
c1a9b12d SL |
364 | /// This outputs: |
365 | /// | |
366 | /// ```text | |
367 | /// The origin is: Point { x: 0, y: 0 } | |
368 | /// ``` | |
369 | /// | |
62682a34 SL |
370 | /// There are a number of `debug_*` methods on `Formatter` to help you with manual |
371 | /// implementations, such as [`debug_struct`][debug_struct]. | |
372 | /// | |
c1a9b12d SL |
373 | /// `Debug` implementations using either `derive` or the debug builder API |
374 | /// on `Formatter` support pretty printing using the alternate flag: `{:#?}`. | |
375 | /// | |
9cc50fc6 | 376 | /// [debug_struct]: ../../std/fmt/struct.Formatter.html#method.debug_struct |
c1a9b12d SL |
377 | /// |
378 | /// Pretty printing with `#?`: | |
379 | /// | |
380 | /// ``` | |
381 | /// #[derive(Debug)] | |
382 | /// struct Point { | |
383 | /// x: i32, | |
384 | /// y: i32, | |
385 | /// } | |
386 | /// | |
387 | /// let origin = Point { x: 0, y: 0 }; | |
388 | /// | |
389 | /// println!("The origin is: {:#?}", origin); | |
390 | /// ``` | |
391 | /// | |
392 | /// This outputs: | |
393 | /// | |
394 | /// ```text | |
395 | /// The origin is: Point { | |
396 | /// x: 0, | |
397 | /// y: 0 | |
398 | /// } | |
399 | /// ``` | |
85aaf69f SL |
400 | #[stable(feature = "rust1", since = "1.0.0")] |
401 | #[rustc_on_unimplemented = "`{Self}` cannot be formatted using `:?`; if it is \ | |
402 | defined in your crate, add `#[derive(Debug)]` or \ | |
403 | manually implement it"] | |
404 | #[lang = "debug_trait"] | |
405 | pub trait Debug { | |
406 | /// Formats the value using the given formatter. | |
407 | #[stable(feature = "rust1", since = "1.0.0")] | |
1a4d82fc JJ |
408 | fn fmt(&self, &mut Formatter) -> Result; |
409 | } | |
410 | ||
c1a9b12d SL |
411 | /// Format trait for an empty format, `{}`. |
412 | /// | |
413 | /// `Display` is similar to [`Debug`][debug], but `Display` is for user-facing | |
414 | /// output, and so cannot be derived. | |
415 | /// | |
416 | /// [debug]: trait.Debug.html | |
417 | /// | |
418 | /// For more information on formatters, see [the module-level documentation][module]. | |
419 | /// | |
b039eaaf | 420 | /// [module]: ../../std/fmt/index.html |
c1a9b12d SL |
421 | /// |
422 | /// # Examples | |
423 | /// | |
424 | /// Implementing `Display` on a type: | |
425 | /// | |
426 | /// ``` | |
427 | /// use std::fmt; | |
428 | /// | |
429 | /// struct Point { | |
430 | /// x: i32, | |
431 | /// y: i32, | |
432 | /// } | |
433 | /// | |
434 | /// impl fmt::Display for Point { | |
435 | /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
436 | /// write!(f, "({}, {})", self.x, self.y) | |
437 | /// } | |
438 | /// } | |
439 | /// | |
440 | /// let origin = Point { x: 0, y: 0 }; | |
441 | /// | |
442 | /// println!("The origin is: {}", origin); | |
443 | /// ``` | |
85aaf69f SL |
444 | #[rustc_on_unimplemented = "`{Self}` cannot be formatted with the default \ |
445 | formatter; try using `:?` instead if you are using \ | |
446 | a format string"] | |
447 | #[stable(feature = "rust1", since = "1.0.0")] | |
448 | pub trait Display { | |
449 | /// Formats the value using the given formatter. | |
450 | #[stable(feature = "rust1", since = "1.0.0")] | |
1a4d82fc JJ |
451 | fn fmt(&self, &mut Formatter) -> Result; |
452 | } | |
453 | ||
c1a9b12d SL |
454 | /// Format trait for the `o` character. |
455 | /// | |
456 | /// The `Octal` trait should format its output as a number in base-8. | |
457 | /// | |
458 | /// The alternate flag, `#`, adds a `0o` in front of the output. | |
459 | /// | |
460 | /// For more information on formatters, see [the module-level documentation][module]. | |
461 | /// | |
b039eaaf | 462 | /// [module]: ../../std/fmt/index.html |
c1a9b12d SL |
463 | /// |
464 | /// # Examples | |
465 | /// | |
466 | /// Basic usage with `i32`: | |
467 | /// | |
468 | /// ``` | |
469 | /// let x = 42; // 42 is '52' in octal | |
470 | /// | |
471 | /// assert_eq!(format!("{:o}", x), "52"); | |
472 | /// assert_eq!(format!("{:#o}", x), "0o52"); | |
473 | /// ``` | |
474 | /// | |
475 | /// Implementing `Octal` on a type: | |
476 | /// | |
477 | /// ``` | |
478 | /// use std::fmt; | |
479 | /// | |
480 | /// struct Length(i32); | |
481 | /// | |
482 | /// impl fmt::Octal for Length { | |
483 | /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
484 | /// let val = self.0; | |
485 | /// | |
486 | /// write!(f, "{:o}", val) // delegate to i32's implementation | |
487 | /// } | |
488 | /// } | |
489 | /// | |
490 | /// let l = Length(9); | |
491 | /// | |
492 | /// println!("l as octal is: {:o}", l); | |
493 | /// ``` | |
85aaf69f | 494 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
495 | pub trait Octal { |
496 | /// Formats the value using the given formatter. | |
85aaf69f | 497 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
498 | fn fmt(&self, &mut Formatter) -> Result; |
499 | } | |
500 | ||
c1a9b12d SL |
501 | /// Format trait for the `b` character. |
502 | /// | |
503 | /// The `Binary` trait should format its output as a number in binary. | |
504 | /// | |
505 | /// The alternate flag, `#`, adds a `0b` in front of the output. | |
506 | /// | |
507 | /// For more information on formatters, see [the module-level documentation][module]. | |
508 | /// | |
b039eaaf | 509 | /// [module]: ../../std/fmt/index.html |
c1a9b12d SL |
510 | /// |
511 | /// # Examples | |
512 | /// | |
513 | /// Basic usage with `i32`: | |
514 | /// | |
515 | /// ``` | |
516 | /// let x = 42; // 42 is '101010' in binary | |
517 | /// | |
518 | /// assert_eq!(format!("{:b}", x), "101010"); | |
519 | /// assert_eq!(format!("{:#b}", x), "0b101010"); | |
520 | /// ``` | |
521 | /// | |
522 | /// Implementing `Binary` on a type: | |
523 | /// | |
524 | /// ``` | |
525 | /// use std::fmt; | |
526 | /// | |
527 | /// struct Length(i32); | |
528 | /// | |
529 | /// impl fmt::Binary for Length { | |
530 | /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
531 | /// let val = self.0; | |
532 | /// | |
533 | /// write!(f, "{:b}", val) // delegate to i32's implementation | |
534 | /// } | |
535 | /// } | |
536 | /// | |
537 | /// let l = Length(107); | |
538 | /// | |
539 | /// println!("l as binary is: {:b}", l); | |
540 | /// ``` | |
85aaf69f | 541 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
542 | pub trait Binary { |
543 | /// Formats the value using the given formatter. | |
85aaf69f | 544 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
545 | fn fmt(&self, &mut Formatter) -> Result; |
546 | } | |
547 | ||
c1a9b12d SL |
548 | /// Format trait for the `x` character. |
549 | /// | |
b039eaaf | 550 | /// The `LowerHex` trait should format its output as a number in hexadecimal, with `a` through `f` |
c1a9b12d SL |
551 | /// in lower case. |
552 | /// | |
553 | /// The alternate flag, `#`, adds a `0x` in front of the output. | |
554 | /// | |
555 | /// For more information on formatters, see [the module-level documentation][module]. | |
556 | /// | |
b039eaaf | 557 | /// [module]: ../../std/fmt/index.html |
c1a9b12d SL |
558 | /// |
559 | /// # Examples | |
560 | /// | |
561 | /// Basic usage with `i32`: | |
562 | /// | |
563 | /// ``` | |
564 | /// let x = 42; // 42 is '2a' in hex | |
565 | /// | |
566 | /// assert_eq!(format!("{:x}", x), "2a"); | |
567 | /// assert_eq!(format!("{:#x}", x), "0x2a"); | |
568 | /// ``` | |
569 | /// | |
570 | /// Implementing `LowerHex` on a type: | |
571 | /// | |
572 | /// ``` | |
573 | /// use std::fmt; | |
574 | /// | |
575 | /// struct Length(i32); | |
576 | /// | |
577 | /// impl fmt::LowerHex for Length { | |
578 | /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
579 | /// let val = self.0; | |
580 | /// | |
581 | /// write!(f, "{:x}", val) // delegate to i32's implementation | |
582 | /// } | |
583 | /// } | |
584 | /// | |
585 | /// let l = Length(9); | |
586 | /// | |
587 | /// println!("l as hex is: {:x}", l); | |
588 | /// ``` | |
85aaf69f | 589 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
590 | pub trait LowerHex { |
591 | /// Formats the value using the given formatter. | |
85aaf69f | 592 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
593 | fn fmt(&self, &mut Formatter) -> Result; |
594 | } | |
595 | ||
c1a9b12d SL |
596 | /// Format trait for the `X` character. |
597 | /// | |
b039eaaf | 598 | /// The `UpperHex` trait should format its output as a number in hexadecimal, with `A` through `F` |
c1a9b12d SL |
599 | /// in upper case. |
600 | /// | |
601 | /// The alternate flag, `#`, adds a `0x` in front of the output. | |
602 | /// | |
603 | /// For more information on formatters, see [the module-level documentation][module]. | |
604 | /// | |
b039eaaf | 605 | /// [module]: ../../std/fmt/index.html |
c1a9b12d SL |
606 | /// |
607 | /// # Examples | |
608 | /// | |
609 | /// Basic usage with `i32`: | |
610 | /// | |
611 | /// ``` | |
612 | /// let x = 42; // 42 is '2A' in hex | |
613 | /// | |
614 | /// assert_eq!(format!("{:X}", x), "2A"); | |
615 | /// assert_eq!(format!("{:#X}", x), "0x2A"); | |
616 | /// ``` | |
617 | /// | |
618 | /// Implementing `UpperHex` on a type: | |
619 | /// | |
620 | /// ``` | |
621 | /// use std::fmt; | |
622 | /// | |
623 | /// struct Length(i32); | |
624 | /// | |
625 | /// impl fmt::UpperHex for Length { | |
626 | /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
627 | /// let val = self.0; | |
628 | /// | |
629 | /// write!(f, "{:X}", val) // delegate to i32's implementation | |
630 | /// } | |
631 | /// } | |
632 | /// | |
633 | /// let l = Length(9); | |
634 | /// | |
635 | /// println!("l as hex is: {:X}", l); | |
636 | /// ``` | |
85aaf69f | 637 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
638 | pub trait UpperHex { |
639 | /// Formats the value using the given formatter. | |
85aaf69f | 640 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
641 | fn fmt(&self, &mut Formatter) -> Result; |
642 | } | |
643 | ||
c1a9b12d SL |
644 | /// Format trait for the `p` character. |
645 | /// | |
646 | /// The `Pointer` trait should format its output as a memory location. This is commonly presented | |
b039eaaf | 647 | /// as hexadecimal. |
c1a9b12d SL |
648 | /// |
649 | /// For more information on formatters, see [the module-level documentation][module]. | |
650 | /// | |
b039eaaf | 651 | /// [module]: ../../std/fmt/index.html |
c1a9b12d SL |
652 | /// |
653 | /// # Examples | |
654 | /// | |
655 | /// Basic usage with `&i32`: | |
656 | /// | |
657 | /// ``` | |
658 | /// let x = &42; | |
659 | /// | |
660 | /// let address = format!("{:p}", x); // this produces something like '0x7f06092ac6d0' | |
661 | /// ``` | |
662 | /// | |
663 | /// Implementing `Pointer` on a type: | |
664 | /// | |
665 | /// ``` | |
666 | /// use std::fmt; | |
667 | /// | |
668 | /// struct Length(i32); | |
669 | /// | |
670 | /// impl fmt::Pointer for Length { | |
671 | /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
672 | /// // use `as` to convert to a `*const T`, which implements Pointer, which we can use | |
673 | /// | |
674 | /// write!(f, "{:p}", self as *const Length) | |
675 | /// } | |
676 | /// } | |
677 | /// | |
678 | /// let l = Length(42); | |
679 | /// | |
680 | /// println!("l is in memory here: {:p}", l); | |
681 | /// ``` | |
85aaf69f | 682 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
683 | pub trait Pointer { |
684 | /// Formats the value using the given formatter. | |
85aaf69f | 685 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
686 | fn fmt(&self, &mut Formatter) -> Result; |
687 | } | |
688 | ||
c1a9b12d SL |
689 | /// Format trait for the `e` character. |
690 | /// | |
691 | /// The `LowerExp` trait should format its output in scientific notation with a lower-case `e`. | |
692 | /// | |
693 | /// For more information on formatters, see [the module-level documentation][module]. | |
694 | /// | |
b039eaaf | 695 | /// [module]: ../../std/fmt/index.html |
c1a9b12d SL |
696 | /// |
697 | /// # Examples | |
698 | /// | |
699 | /// Basic usage with `i32`: | |
700 | /// | |
701 | /// ``` | |
702 | /// let x = 42.0; // 42.0 is '4.2e1' in scientific notation | |
703 | /// | |
704 | /// assert_eq!(format!("{:e}", x), "4.2e1"); | |
705 | /// ``` | |
706 | /// | |
707 | /// Implementing `LowerExp` on a type: | |
708 | /// | |
709 | /// ``` | |
710 | /// use std::fmt; | |
711 | /// | |
712 | /// struct Length(i32); | |
713 | /// | |
714 | /// impl fmt::LowerExp for Length { | |
715 | /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
716 | /// let val = self.0; | |
717 | /// write!(f, "{}e1", val / 10) | |
718 | /// } | |
719 | /// } | |
720 | /// | |
721 | /// let l = Length(100); | |
722 | /// | |
723 | /// println!("l in scientific notation is: {:e}", l); | |
724 | /// ``` | |
85aaf69f | 725 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
726 | pub trait LowerExp { |
727 | /// Formats the value using the given formatter. | |
85aaf69f | 728 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
729 | fn fmt(&self, &mut Formatter) -> Result; |
730 | } | |
731 | ||
c1a9b12d SL |
732 | /// Format trait for the `E` character. |
733 | /// | |
734 | /// The `UpperExp` trait should format its output in scientific notation with an upper-case `E`. | |
735 | /// | |
736 | /// For more information on formatters, see [the module-level documentation][module]. | |
737 | /// | |
b039eaaf | 738 | /// [module]: ../../std/fmt/index.html |
c1a9b12d SL |
739 | /// |
740 | /// # Examples | |
741 | /// | |
742 | /// Basic usage with `f32`: | |
743 | /// | |
744 | /// ``` | |
745 | /// let x = 42.0; // 42.0 is '4.2E1' in scientific notation | |
746 | /// | |
747 | /// assert_eq!(format!("{:E}", x), "4.2E1"); | |
748 | /// ``` | |
749 | /// | |
750 | /// Implementing `UpperExp` on a type: | |
751 | /// | |
752 | /// ``` | |
753 | /// use std::fmt; | |
754 | /// | |
755 | /// struct Length(i32); | |
756 | /// | |
757 | /// impl fmt::UpperExp for Length { | |
758 | /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
759 | /// let val = self.0; | |
760 | /// write!(f, "{}E1", val / 10) | |
761 | /// } | |
762 | /// } | |
763 | /// | |
764 | /// let l = Length(100); | |
765 | /// | |
766 | /// println!("l in scientific notation is: {:E}", l); | |
767 | /// ``` | |
85aaf69f | 768 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
769 | pub trait UpperExp { |
770 | /// Formats the value using the given formatter. | |
85aaf69f | 771 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
772 | fn fmt(&self, &mut Formatter) -> Result; |
773 | } | |
774 | ||
775 | /// The `write` function takes an output stream, a precompiled format string, | |
776 | /// and a list of arguments. The arguments will be formatted according to the | |
777 | /// specified format string into the output stream provided. | |
778 | /// | |
779 | /// # Arguments | |
780 | /// | |
781 | /// * output - the buffer to write output to | |
782 | /// * args - the precompiled arguments generated by `format_args!` | |
a7813a04 XL |
783 | /// |
784 | /// # Examples | |
785 | /// | |
786 | /// Basic usage: | |
787 | /// | |
788 | /// ``` | |
789 | /// use std::fmt; | |
790 | /// | |
791 | /// let mut output = String::new(); | |
792 | /// fmt::write(&mut output, format_args!("Hello {}!", "world")) | |
793 | /// .expect("Error occurred while trying to write in String"); | |
794 | /// assert_eq!(output, "Hello world!"); | |
795 | /// ``` | |
796 | /// | |
797 | /// Please note that using [`write!`][write_macro] might be preferrable. Example: | |
798 | /// | |
799 | /// ``` | |
800 | /// use std::fmt::Write; | |
801 | /// | |
802 | /// let mut output = String::new(); | |
803 | /// write!(&mut output, "Hello {}!", "world") | |
804 | /// .expect("Error occurred while trying to write in String"); | |
805 | /// assert_eq!(output, "Hello world!"); | |
806 | /// ``` | |
807 | /// | |
808 | /// [write_macro]: ../../std/macro.write!.html | |
85aaf69f SL |
809 | #[stable(feature = "rust1", since = "1.0.0")] |
810 | pub fn write(output: &mut Write, args: Arguments) -> Result { | |
1a4d82fc JJ |
811 | let mut formatter = Formatter { |
812 | flags: 0, | |
813 | width: None, | |
814 | precision: None, | |
815 | buf: output, | |
54a0048b | 816 | align: rt::v1::Alignment::Unknown, |
1a4d82fc JJ |
817 | fill: ' ', |
818 | args: args.args, | |
819 | curarg: args.args.iter(), | |
820 | }; | |
821 | ||
822 | let mut pieces = args.pieces.iter(); | |
823 | ||
824 | match args.fmt { | |
825 | None => { | |
826 | // We can use default formatting parameters for all arguments. | |
827 | for (arg, piece) in args.args.iter().zip(pieces.by_ref()) { | |
54a0048b SL |
828 | formatter.buf.write_str(*piece)?; |
829 | (arg.formatter)(arg.value, &mut formatter)?; | |
1a4d82fc JJ |
830 | } |
831 | } | |
832 | Some(fmt) => { | |
833 | // Every spec has a corresponding argument that is preceded by | |
834 | // a string piece. | |
835 | for (arg, piece) in fmt.iter().zip(pieces.by_ref()) { | |
54a0048b SL |
836 | formatter.buf.write_str(*piece)?; |
837 | formatter.run(arg)?; | |
1a4d82fc JJ |
838 | } |
839 | } | |
840 | } | |
841 | ||
842 | // There can be only one trailing string piece left. | |
3157f602 XL |
843 | if let Some(piece) = pieces.next() { |
844 | formatter.buf.write_str(*piece)?; | |
1a4d82fc JJ |
845 | } |
846 | ||
847 | Ok(()) | |
848 | } | |
849 | ||
850 | impl<'a> Formatter<'a> { | |
851 | ||
852 | // First up is the collection of functions used to execute a format string | |
853 | // at runtime. This consumes all of the compile-time statics generated by | |
854 | // the format! syntax extension. | |
85aaf69f | 855 | fn run(&mut self, arg: &rt::v1::Argument) -> Result { |
1a4d82fc JJ |
856 | // Fill in the format parameters into the formatter |
857 | self.fill = arg.format.fill; | |
858 | self.align = arg.format.align; | |
859 | self.flags = arg.format.flags; | |
860 | self.width = self.getcount(&arg.format.width); | |
861 | self.precision = self.getcount(&arg.format.precision); | |
862 | ||
863 | // Extract the correct argument | |
864 | let value = match arg.position { | |
85aaf69f SL |
865 | rt::v1::Position::Next => { *self.curarg.next().unwrap() } |
866 | rt::v1::Position::At(i) => self.args[i], | |
1a4d82fc JJ |
867 | }; |
868 | ||
869 | // Then actually do some printing | |
870 | (value.formatter)(value.value, self) | |
871 | } | |
872 | ||
c34b1796 | 873 | fn getcount(&mut self, cnt: &rt::v1::Count) -> Option<usize> { |
1a4d82fc | 874 | match *cnt { |
85aaf69f SL |
875 | rt::v1::Count::Is(n) => Some(n), |
876 | rt::v1::Count::Implied => None, | |
877 | rt::v1::Count::Param(i) => { | |
c34b1796 | 878 | self.args[i].as_usize() |
1a4d82fc | 879 | } |
85aaf69f | 880 | rt::v1::Count::NextParam => { |
c34b1796 | 881 | self.curarg.next().and_then(|arg| arg.as_usize()) |
1a4d82fc JJ |
882 | } |
883 | } | |
884 | } | |
885 | ||
886 | // Helper methods used for padding and processing formatting arguments that | |
887 | // all formatting traits can use. | |
888 | ||
889 | /// Performs the correct padding for an integer which has already been | |
85aaf69f SL |
890 | /// emitted into a str. The str should *not* contain the sign for the |
891 | /// integer, that will be added by this method. | |
1a4d82fc JJ |
892 | /// |
893 | /// # Arguments | |
894 | /// | |
9cc50fc6 | 895 | /// * is_nonnegative - whether the original integer was either positive or zero. |
c34b1796 | 896 | /// * prefix - if the '#' character (Alternate) is provided, this |
1a4d82fc JJ |
897 | /// is the prefix to put in front of the number. |
898 | /// * buf - the byte array that the number has been formatted into | |
899 | /// | |
900 | /// This function will correctly account for the flags provided as well as | |
901 | /// the minimum width. It will not take precision into account. | |
85aaf69f | 902 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 903 | pub fn pad_integral(&mut self, |
9cc50fc6 | 904 | is_nonnegative: bool, |
1a4d82fc JJ |
905 | prefix: &str, |
906 | buf: &str) | |
907 | -> Result { | |
908 | use char::CharExt; | |
1a4d82fc JJ |
909 | |
910 | let mut width = buf.len(); | |
911 | ||
912 | let mut sign = None; | |
9cc50fc6 | 913 | if !is_nonnegative { |
1a4d82fc | 914 | sign = Some('-'); width += 1; |
b039eaaf | 915 | } else if self.sign_plus() { |
1a4d82fc JJ |
916 | sign = Some('+'); width += 1; |
917 | } | |
918 | ||
919 | let mut prefixed = false; | |
b039eaaf | 920 | if self.alternate() { |
92a42be0 | 921 | prefixed = true; width += prefix.chars().count(); |
1a4d82fc JJ |
922 | } |
923 | ||
924 | // Writes the sign if it exists, and then the prefix if it was requested | |
85aaf69f SL |
925 | let write_prefix = |f: &mut Formatter| { |
926 | if let Some(c) = sign { | |
54a0048b SL |
927 | f.buf.write_str(unsafe { |
928 | str::from_utf8_unchecked(c.encode_utf8().as_slice()) | |
929 | })?; | |
1a4d82fc JJ |
930 | } |
931 | if prefixed { f.buf.write_str(prefix) } | |
932 | else { Ok(()) } | |
933 | }; | |
934 | ||
935 | // The `width` field is more of a `min-width` parameter at this point. | |
936 | match self.width { | |
937 | // If there's no minimum length requirements then we can just | |
938 | // write the bytes. | |
939 | None => { | |
54a0048b | 940 | write_prefix(self)?; self.buf.write_str(buf) |
1a4d82fc JJ |
941 | } |
942 | // Check if we're over the minimum width, if so then we can also | |
943 | // just write the bytes. | |
944 | Some(min) if width >= min => { | |
54a0048b | 945 | write_prefix(self)?; self.buf.write_str(buf) |
1a4d82fc JJ |
946 | } |
947 | // The sign and prefix goes before the padding if the fill character | |
948 | // is zero | |
b039eaaf | 949 | Some(min) if self.sign_aware_zero_pad() => { |
1a4d82fc | 950 | self.fill = '0'; |
54a0048b SL |
951 | write_prefix(self)?; |
952 | self.with_padding(min - width, rt::v1::Alignment::Right, |f| { | |
1a4d82fc JJ |
953 | f.buf.write_str(buf) |
954 | }) | |
955 | } | |
956 | // Otherwise, the sign and prefix goes after the padding | |
957 | Some(min) => { | |
54a0048b SL |
958 | self.with_padding(min - width, rt::v1::Alignment::Right, |f| { |
959 | write_prefix(f)?; f.buf.write_str(buf) | |
1a4d82fc JJ |
960 | }) |
961 | } | |
962 | } | |
963 | } | |
964 | ||
965 | /// This function takes a string slice and emits it to the internal buffer | |
966 | /// after applying the relevant formatting flags specified. The flags | |
967 | /// recognized for generic strings are: | |
968 | /// | |
969 | /// * width - the minimum width of what to emit | |
970 | /// * fill/align - what to emit and where to emit it if the string | |
971 | /// provided needs to be padded | |
972 | /// * precision - the maximum length to emit, the string is truncated if it | |
973 | /// is longer than this length | |
974 | /// | |
975 | /// Notably this function ignored the `flag` parameters | |
85aaf69f | 976 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
977 | pub fn pad(&mut self, s: &str) -> Result { |
978 | // Make sure there's a fast path up front | |
979 | if self.width.is_none() && self.precision.is_none() { | |
980 | return self.buf.write_str(s); | |
981 | } | |
982 | // The `precision` field can be interpreted as a `max-width` for the | |
5bcae85e SL |
983 | // string being formatted. |
984 | let s = if let Some(max) = self.precision { | |
985 | // If our string is longer that the precision, then we must have | |
986 | // truncation. However other flags like `fill`, `width` and `align` | |
987 | // must act as always. | |
92a42be0 | 988 | if let Some((i, _)) = s.char_indices().skip(max).next() { |
5bcae85e SL |
989 | &s[..i] |
990 | } else { | |
991 | &s | |
1a4d82fc | 992 | } |
5bcae85e SL |
993 | } else { |
994 | &s | |
995 | }; | |
1a4d82fc JJ |
996 | // The `width` field is more of a `min-width` parameter at this point. |
997 | match self.width { | |
998 | // If we're under the maximum length, and there's no minimum length | |
999 | // requirements, then we can just emit the string | |
1000 | None => self.buf.write_str(s), | |
1001 | // If we're under the maximum width, check if we're over the minimum | |
1002 | // width, if so it's as easy as just emitting the string. | |
92a42be0 | 1003 | Some(width) if s.chars().count() >= width => { |
1a4d82fc JJ |
1004 | self.buf.write_str(s) |
1005 | } | |
1006 | // If we're under both the maximum and the minimum width, then fill | |
1007 | // up the minimum width with the specified string + some alignment. | |
1008 | Some(width) => { | |
54a0048b SL |
1009 | let align = rt::v1::Alignment::Left; |
1010 | self.with_padding(width - s.chars().count(), align, |me| { | |
1a4d82fc JJ |
1011 | me.buf.write_str(s) |
1012 | }) | |
1013 | } | |
1014 | } | |
1015 | } | |
1016 | ||
1017 | /// Runs a callback, emitting the correct padding either before or | |
1018 | /// afterwards depending on whether right or left alignment is requested. | |
54a0048b | 1019 | fn with_padding<F>(&mut self, padding: usize, default: rt::v1::Alignment, |
85aaf69f SL |
1020 | f: F) -> Result |
1021 | where F: FnOnce(&mut Formatter) -> Result, | |
1a4d82fc JJ |
1022 | { |
1023 | use char::CharExt; | |
1024 | let align = match self.align { | |
54a0048b | 1025 | rt::v1::Alignment::Unknown => default, |
1a4d82fc JJ |
1026 | _ => self.align |
1027 | }; | |
1028 | ||
1029 | let (pre_pad, post_pad) = match align { | |
54a0048b SL |
1030 | rt::v1::Alignment::Left => (0, padding), |
1031 | rt::v1::Alignment::Right | | |
1032 | rt::v1::Alignment::Unknown => (padding, 0), | |
1033 | rt::v1::Alignment::Center => (padding / 2, (padding + 1) / 2), | |
1a4d82fc JJ |
1034 | }; |
1035 | ||
54a0048b SL |
1036 | let fill = self.fill.encode_utf8(); |
1037 | let fill = unsafe { | |
1038 | str::from_utf8_unchecked(fill.as_slice()) | |
1039 | }; | |
1a4d82fc | 1040 | |
85aaf69f | 1041 | for _ in 0..pre_pad { |
54a0048b | 1042 | self.buf.write_str(fill)?; |
1a4d82fc JJ |
1043 | } |
1044 | ||
54a0048b | 1045 | f(self)?; |
1a4d82fc | 1046 | |
85aaf69f | 1047 | for _ in 0..post_pad { |
54a0048b | 1048 | self.buf.write_str(fill)?; |
1a4d82fc JJ |
1049 | } |
1050 | ||
1051 | Ok(()) | |
1052 | } | |
1053 | ||
d9579d0f AL |
1054 | /// Takes the formatted parts and applies the padding. |
1055 | /// Assumes that the caller already has rendered the parts with required precision, | |
1056 | /// so that `self.precision` can be ignored. | |
1057 | fn pad_formatted_parts(&mut self, formatted: &flt2dec::Formatted) -> Result { | |
1058 | if let Some(mut width) = self.width { | |
1059 | // for the sign-aware zero padding, we render the sign first and | |
1060 | // behave as if we had no sign from the beginning. | |
1061 | let mut formatted = formatted.clone(); | |
1062 | let mut align = self.align; | |
1063 | let old_fill = self.fill; | |
b039eaaf | 1064 | if self.sign_aware_zero_pad() { |
d9579d0f AL |
1065 | // a sign always goes first |
1066 | let sign = unsafe { str::from_utf8_unchecked(formatted.sign) }; | |
54a0048b | 1067 | self.buf.write_str(sign)?; |
d9579d0f AL |
1068 | |
1069 | // remove the sign from the formatted parts | |
1070 | formatted.sign = b""; | |
1071 | width = if width < sign.len() { 0 } else { width - sign.len() }; | |
54a0048b | 1072 | align = rt::v1::Alignment::Right; |
d9579d0f AL |
1073 | self.fill = '0'; |
1074 | } | |
1075 | ||
1076 | // remaining parts go through the ordinary padding process. | |
1077 | let len = formatted.len(); | |
1078 | let ret = if width <= len { // no padding | |
1079 | self.write_formatted_parts(&formatted) | |
1080 | } else { | |
1081 | self.with_padding(width - len, align, |f| { | |
1082 | f.write_formatted_parts(&formatted) | |
1083 | }) | |
1084 | }; | |
1085 | self.fill = old_fill; | |
1086 | ret | |
1087 | } else { | |
1088 | // this is the common case and we take a shortcut | |
1089 | self.write_formatted_parts(formatted) | |
1090 | } | |
1091 | } | |
1092 | ||
1093 | fn write_formatted_parts(&mut self, formatted: &flt2dec::Formatted) -> Result { | |
1094 | fn write_bytes(buf: &mut Write, s: &[u8]) -> Result { | |
1095 | buf.write_str(unsafe { str::from_utf8_unchecked(s) }) | |
1096 | } | |
1097 | ||
1098 | if !formatted.sign.is_empty() { | |
54a0048b | 1099 | write_bytes(self.buf, formatted.sign)?; |
d9579d0f AL |
1100 | } |
1101 | for part in formatted.parts { | |
1102 | match *part { | |
1103 | flt2dec::Part::Zero(mut nzeroes) => { | |
1104 | const ZEROES: &'static str = // 64 zeroes | |
1105 | "0000000000000000000000000000000000000000000000000000000000000000"; | |
1106 | while nzeroes > ZEROES.len() { | |
54a0048b | 1107 | self.buf.write_str(ZEROES)?; |
d9579d0f AL |
1108 | nzeroes -= ZEROES.len(); |
1109 | } | |
1110 | if nzeroes > 0 { | |
54a0048b | 1111 | self.buf.write_str(&ZEROES[..nzeroes])?; |
d9579d0f AL |
1112 | } |
1113 | } | |
1114 | flt2dec::Part::Num(mut v) => { | |
1115 | let mut s = [0; 5]; | |
1116 | let len = part.len(); | |
1117 | for c in s[..len].iter_mut().rev() { | |
1118 | *c = b'0' + (v % 10) as u8; | |
1119 | v /= 10; | |
1120 | } | |
54a0048b | 1121 | write_bytes(self.buf, &s[..len])?; |
d9579d0f AL |
1122 | } |
1123 | flt2dec::Part::Copy(buf) => { | |
54a0048b | 1124 | write_bytes(self.buf, buf)?; |
d9579d0f AL |
1125 | } |
1126 | } | |
1127 | } | |
1128 | Ok(()) | |
1129 | } | |
1130 | ||
1a4d82fc JJ |
1131 | /// Writes some data to the underlying buffer contained within this |
1132 | /// formatter. | |
85aaf69f | 1133 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1134 | pub fn write_str(&mut self, data: &str) -> Result { |
1135 | self.buf.write_str(data) | |
1136 | } | |
1137 | ||
1138 | /// Writes some formatted information into this instance | |
85aaf69f | 1139 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1140 | pub fn write_fmt(&mut self, fmt: Arguments) -> Result { |
1141 | write(self.buf, fmt) | |
1142 | } | |
1143 | ||
1144 | /// Flags for formatting (packed version of rt::Flag) | |
85aaf69f | 1145 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 1146 | pub fn flags(&self) -> u32 { self.flags } |
1a4d82fc JJ |
1147 | |
1148 | /// Character used as 'fill' whenever there is alignment | |
b039eaaf | 1149 | #[stable(feature = "fmt_flags", since = "1.5.0")] |
1a4d82fc JJ |
1150 | pub fn fill(&self) -> char { self.fill } |
1151 | ||
1152 | /// Flag indicating what form of alignment was requested | |
b039eaaf | 1153 | #[unstable(feature = "fmt_flags_align", reason = "method was just created", |
e9174d1e | 1154 | issue = "27726")] |
54a0048b SL |
1155 | pub fn align(&self) -> Alignment { |
1156 | match self.align { | |
1157 | rt::v1::Alignment::Left => Alignment::Left, | |
1158 | rt::v1::Alignment::Right => Alignment::Right, | |
1159 | rt::v1::Alignment::Center => Alignment::Center, | |
1160 | rt::v1::Alignment::Unknown => Alignment::Unknown, | |
1161 | } | |
1162 | } | |
1a4d82fc JJ |
1163 | |
1164 | /// Optionally specified integer width that the output should be | |
b039eaaf | 1165 | #[stable(feature = "fmt_flags", since = "1.5.0")] |
c34b1796 | 1166 | pub fn width(&self) -> Option<usize> { self.width } |
1a4d82fc JJ |
1167 | |
1168 | /// Optionally specified precision for numeric types | |
b039eaaf | 1169 | #[stable(feature = "fmt_flags", since = "1.5.0")] |
c34b1796 AL |
1170 | pub fn precision(&self) -> Option<usize> { self.precision } |
1171 | ||
b039eaaf SL |
1172 | /// Determines if the `+` flag was specified. |
1173 | #[stable(feature = "fmt_flags", since = "1.5.0")] | |
1174 | pub fn sign_plus(&self) -> bool { self.flags & (1 << FlagV1::SignPlus as u32) != 0 } | |
1175 | ||
1176 | /// Determines if the `-` flag was specified. | |
1177 | #[stable(feature = "fmt_flags", since = "1.5.0")] | |
1178 | pub fn sign_minus(&self) -> bool { self.flags & (1 << FlagV1::SignMinus as u32) != 0 } | |
1179 | ||
1180 | /// Determines if the `#` flag was specified. | |
1181 | #[stable(feature = "fmt_flags", since = "1.5.0")] | |
1182 | pub fn alternate(&self) -> bool { self.flags & (1 << FlagV1::Alternate as u32) != 0 } | |
1183 | ||
1184 | /// Determines if the `0` flag was specified. | |
1185 | #[stable(feature = "fmt_flags", since = "1.5.0")] | |
1186 | pub fn sign_aware_zero_pad(&self) -> bool { | |
1187 | self.flags & (1 << FlagV1::SignAwareZeroPad as u32) != 0 | |
1188 | } | |
1189 | ||
c34b1796 AL |
1190 | /// Creates a `DebugStruct` builder designed to assist with creation of |
1191 | /// `fmt::Debug` implementations for structs. | |
1192 | /// | |
1193 | /// # Examples | |
1194 | /// | |
1195 | /// ```rust | |
c34b1796 AL |
1196 | /// use std::fmt; |
1197 | /// | |
1198 | /// struct Foo { | |
1199 | /// bar: i32, | |
1200 | /// baz: String, | |
1201 | /// } | |
1202 | /// | |
1203 | /// impl fmt::Debug for Foo { | |
1204 | /// fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { | |
1205 | /// fmt.debug_struct("Foo") | |
1206 | /// .field("bar", &self.bar) | |
1207 | /// .field("baz", &self.baz) | |
1208 | /// .finish() | |
1209 | /// } | |
1210 | /// } | |
1211 | /// | |
1212 | /// // prints "Foo { bar: 10, baz: "Hello World" }" | |
1213 | /// println!("{:?}", Foo { bar: 10, baz: "Hello World".to_string() }); | |
1214 | /// ``` | |
62682a34 | 1215 | #[stable(feature = "debug_builders", since = "1.2.0")] |
c34b1796 AL |
1216 | #[inline] |
1217 | pub fn debug_struct<'b>(&'b mut self, name: &str) -> DebugStruct<'b, 'a> { | |
1218 | builders::debug_struct_new(self, name) | |
1219 | } | |
1220 | ||
1221 | /// Creates a `DebugTuple` builder designed to assist with creation of | |
1222 | /// `fmt::Debug` implementations for tuple structs. | |
1223 | /// | |
1224 | /// # Examples | |
1225 | /// | |
1226 | /// ```rust | |
c34b1796 AL |
1227 | /// use std::fmt; |
1228 | /// | |
1229 | /// struct Foo(i32, String); | |
1230 | /// | |
1231 | /// impl fmt::Debug for Foo { | |
1232 | /// fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { | |
1233 | /// fmt.debug_tuple("Foo") | |
1234 | /// .field(&self.0) | |
1235 | /// .field(&self.1) | |
1236 | /// .finish() | |
1237 | /// } | |
1238 | /// } | |
1239 | /// | |
1240 | /// // prints "Foo(10, "Hello World")" | |
1241 | /// println!("{:?}", Foo(10, "Hello World".to_string())); | |
1242 | /// ``` | |
62682a34 | 1243 | #[stable(feature = "debug_builders", since = "1.2.0")] |
c34b1796 AL |
1244 | #[inline] |
1245 | pub fn debug_tuple<'b>(&'b mut self, name: &str) -> DebugTuple<'b, 'a> { | |
1246 | builders::debug_tuple_new(self, name) | |
1247 | } | |
1248 | ||
1249 | /// Creates a `DebugList` builder designed to assist with creation of | |
1250 | /// `fmt::Debug` implementations for list-like structures. | |
1251 | /// | |
1252 | /// # Examples | |
1253 | /// | |
1254 | /// ```rust | |
c34b1796 AL |
1255 | /// use std::fmt; |
1256 | /// | |
1257 | /// struct Foo(Vec<i32>); | |
1258 | /// | |
1259 | /// impl fmt::Debug for Foo { | |
1260 | /// fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { | |
62682a34 | 1261 | /// fmt.debug_list().entries(self.0.iter()).finish() |
c34b1796 AL |
1262 | /// } |
1263 | /// } | |
1264 | /// | |
1265 | /// // prints "[10, 11]" | |
1266 | /// println!("{:?}", Foo(vec![10, 11])); | |
1267 | /// ``` | |
62682a34 | 1268 | #[stable(feature = "debug_builders", since = "1.2.0")] |
c34b1796 AL |
1269 | #[inline] |
1270 | pub fn debug_list<'b>(&'b mut self) -> DebugList<'b, 'a> { | |
1271 | builders::debug_list_new(self) | |
1272 | } | |
1273 | ||
1274 | /// Creates a `DebugSet` builder designed to assist with creation of | |
1275 | /// `fmt::Debug` implementations for set-like structures. | |
1276 | /// | |
1277 | /// # Examples | |
1278 | /// | |
1279 | /// ```rust | |
c34b1796 AL |
1280 | /// use std::fmt; |
1281 | /// | |
1282 | /// struct Foo(Vec<i32>); | |
1283 | /// | |
1284 | /// impl fmt::Debug for Foo { | |
1285 | /// fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { | |
62682a34 | 1286 | /// fmt.debug_set().entries(self.0.iter()).finish() |
c34b1796 AL |
1287 | /// } |
1288 | /// } | |
1289 | /// | |
1290 | /// // prints "{10, 11}" | |
1291 | /// println!("{:?}", Foo(vec![10, 11])); | |
1292 | /// ``` | |
62682a34 | 1293 | #[stable(feature = "debug_builders", since = "1.2.0")] |
c34b1796 AL |
1294 | #[inline] |
1295 | pub fn debug_set<'b>(&'b mut self) -> DebugSet<'b, 'a> { | |
1296 | builders::debug_set_new(self) | |
1297 | } | |
1298 | ||
1299 | /// Creates a `DebugMap` builder designed to assist with creation of | |
1300 | /// `fmt::Debug` implementations for map-like structures. | |
1301 | /// | |
1302 | /// # Examples | |
1303 | /// | |
1304 | /// ```rust | |
c34b1796 AL |
1305 | /// use std::fmt; |
1306 | /// | |
1307 | /// struct Foo(Vec<(String, i32)>); | |
1308 | /// | |
1309 | /// impl fmt::Debug for Foo { | |
1310 | /// fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { | |
62682a34 | 1311 | /// fmt.debug_map().entries(self.0.iter().map(|&(ref k, ref v)| (k, v))).finish() |
c34b1796 AL |
1312 | /// } |
1313 | /// } | |
1314 | /// | |
1315 | /// // prints "{"A": 10, "B": 11}" | |
1316 | /// println!("{:?}", Foo(vec![("A".to_string(), 10), ("B".to_string(), 11)])); | |
1317 | /// ``` | |
62682a34 | 1318 | #[stable(feature = "debug_builders", since = "1.2.0")] |
c34b1796 AL |
1319 | #[inline] |
1320 | pub fn debug_map<'b>(&'b mut self) -> DebugMap<'b, 'a> { | |
1321 | builders::debug_map_new(self) | |
1322 | } | |
1a4d82fc JJ |
1323 | } |
1324 | ||
62682a34 SL |
1325 | #[stable(since = "1.2.0", feature = "formatter_write")] |
1326 | impl<'a> Write for Formatter<'a> { | |
1327 | fn write_str(&mut self, s: &str) -> Result { | |
1328 | self.buf.write_str(s) | |
1329 | } | |
1330 | ||
1331 | fn write_char(&mut self, c: char) -> Result { | |
1332 | self.buf.write_char(c) | |
1333 | } | |
1334 | ||
1335 | fn write_fmt(&mut self, args: Arguments) -> Result { | |
1336 | write(self.buf, args) | |
1337 | } | |
1338 | } | |
1339 | ||
85aaf69f SL |
1340 | #[stable(feature = "rust1", since = "1.0.0")] |
1341 | impl Display for Error { | |
1a4d82fc | 1342 | fn fmt(&self, f: &mut Formatter) -> Result { |
85aaf69f | 1343 | Display::fmt("an error occurred when formatting an argument", f) |
1a4d82fc JJ |
1344 | } |
1345 | } | |
1346 | ||
1a4d82fc JJ |
1347 | // Implementations of the core formatting traits |
1348 | ||
1349 | macro_rules! fmt_refs { | |
1350 | ($($tr:ident),*) => { | |
1351 | $( | |
85aaf69f | 1352 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1353 | impl<'a, T: ?Sized + $tr> $tr for &'a T { |
1354 | fn fmt(&self, f: &mut Formatter) -> Result { $tr::fmt(&**self, f) } | |
1355 | } | |
85aaf69f | 1356 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1357 | impl<'a, T: ?Sized + $tr> $tr for &'a mut T { |
1358 | fn fmt(&self, f: &mut Formatter) -> Result { $tr::fmt(&**self, f) } | |
1359 | } | |
1360 | )* | |
1361 | } | |
1362 | } | |
1363 | ||
85aaf69f | 1364 | fmt_refs! { Debug, Display, Octal, Binary, LowerHex, UpperHex, LowerExp, UpperExp } |
1a4d82fc | 1365 | |
5bcae85e SL |
1366 | // Note: This macro is a temporary hack that can be remove once we are building with a compiler |
1367 | // that supports `!` | |
1368 | macro_rules! not_stage0 { | |
1369 | () => { | |
1370 | #[unstable(feature = "never_type", issue = "35121")] | |
1371 | impl Debug for ! { | |
1372 | fn fmt(&self, _: &mut Formatter) -> Result { | |
1373 | *self | |
1374 | } | |
1375 | } | |
1376 | ||
1377 | #[unstable(feature = "never_type", issue = "35121")] | |
1378 | impl Display for ! { | |
1379 | fn fmt(&self, _: &mut Formatter) -> Result { | |
1380 | *self | |
1381 | } | |
1382 | } | |
1383 | } | |
1384 | } | |
1385 | ||
1386 | #[cfg(not(stage0))] | |
1387 | not_stage0!(); | |
1388 | ||
85aaf69f SL |
1389 | #[stable(feature = "rust1", since = "1.0.0")] |
1390 | impl Debug for bool { | |
1a4d82fc | 1391 | fn fmt(&self, f: &mut Formatter) -> Result { |
85aaf69f | 1392 | Display::fmt(self, f) |
1a4d82fc JJ |
1393 | } |
1394 | } | |
1395 | ||
85aaf69f SL |
1396 | #[stable(feature = "rust1", since = "1.0.0")] |
1397 | impl Display for bool { | |
1a4d82fc | 1398 | fn fmt(&self, f: &mut Formatter) -> Result { |
85aaf69f | 1399 | Display::fmt(if *self { "true" } else { "false" }, f) |
1a4d82fc JJ |
1400 | } |
1401 | } | |
1402 | ||
85aaf69f SL |
1403 | #[stable(feature = "rust1", since = "1.0.0")] |
1404 | impl Debug for str { | |
1a4d82fc | 1405 | fn fmt(&self, f: &mut Formatter) -> Result { |
54a0048b | 1406 | f.write_char('"')?; |
b039eaaf SL |
1407 | let mut from = 0; |
1408 | for (i, c) in self.char_indices() { | |
5bcae85e | 1409 | let esc = c.escape_debug(); |
b039eaaf | 1410 | // If char needs escaping, flush backlog so far and write, else skip |
3157f602 | 1411 | if esc.len() != 1 { |
54a0048b | 1412 | f.write_str(&self[from..i])?; |
b039eaaf | 1413 | for c in esc { |
54a0048b | 1414 | f.write_char(c)?; |
b039eaaf SL |
1415 | } |
1416 | from = i + c.len_utf8(); | |
1417 | } | |
1a4d82fc | 1418 | } |
54a0048b | 1419 | f.write_str(&self[from..])?; |
b039eaaf | 1420 | f.write_char('"') |
1a4d82fc JJ |
1421 | } |
1422 | } | |
1423 | ||
85aaf69f SL |
1424 | #[stable(feature = "rust1", since = "1.0.0")] |
1425 | impl Display for str { | |
1a4d82fc JJ |
1426 | fn fmt(&self, f: &mut Formatter) -> Result { |
1427 | f.pad(self) | |
1428 | } | |
1429 | } | |
1430 | ||
85aaf69f SL |
1431 | #[stable(feature = "rust1", since = "1.0.0")] |
1432 | impl Debug for char { | |
1a4d82fc | 1433 | fn fmt(&self, f: &mut Formatter) -> Result { |
54a0048b | 1434 | f.write_char('\'')?; |
5bcae85e | 1435 | for c in self.escape_debug() { |
54a0048b | 1436 | f.write_char(c)? |
1a4d82fc | 1437 | } |
b039eaaf | 1438 | f.write_char('\'') |
1a4d82fc JJ |
1439 | } |
1440 | } | |
1441 | ||
85aaf69f SL |
1442 | #[stable(feature = "rust1", since = "1.0.0")] |
1443 | impl Display for char { | |
1a4d82fc | 1444 | fn fmt(&self, f: &mut Formatter) -> Result { |
62682a34 SL |
1445 | if f.width.is_none() && f.precision.is_none() { |
1446 | f.write_char(*self) | |
1447 | } else { | |
54a0048b SL |
1448 | f.pad(unsafe { |
1449 | str::from_utf8_unchecked(self.encode_utf8().as_slice()) | |
1450 | }) | |
62682a34 | 1451 | } |
1a4d82fc JJ |
1452 | } |
1453 | } | |
1454 | ||
85aaf69f | 1455 | #[stable(feature = "rust1", since = "1.0.0")] |
7453a54e | 1456 | impl<T: ?Sized> Pointer for *const T { |
1a4d82fc | 1457 | fn fmt(&self, f: &mut Formatter) -> Result { |
9346a6ac AL |
1458 | let old_width = f.width; |
1459 | let old_flags = f.flags; | |
1460 | ||
1461 | // The alternate flag is already treated by LowerHex as being special- | |
1462 | // it denotes whether to prefix with 0x. We use it to work out whether | |
1463 | // or not to zero extend, and then unconditionally set it to get the | |
1464 | // prefix. | |
b039eaaf | 1465 | if f.alternate() { |
9346a6ac AL |
1466 | f.flags |= 1 << (FlagV1::SignAwareZeroPad as u32); |
1467 | ||
1468 | if let None = f.width { | |
9cc50fc6 | 1469 | f.width = Some(((mem::size_of::<usize>() * 8) / 4) + 2); |
9346a6ac AL |
1470 | } |
1471 | } | |
c34b1796 | 1472 | f.flags |= 1 << (FlagV1::Alternate as u32); |
9346a6ac | 1473 | |
7453a54e | 1474 | let ret = LowerHex::fmt(&(*self as *const () as usize), f); |
9346a6ac AL |
1475 | |
1476 | f.width = old_width; | |
1477 | f.flags = old_flags; | |
1478 | ||
1a4d82fc JJ |
1479 | ret |
1480 | } | |
1481 | } | |
1482 | ||
85aaf69f | 1483 | #[stable(feature = "rust1", since = "1.0.0")] |
7453a54e | 1484 | impl<T: ?Sized> Pointer for *mut T { |
1a4d82fc JJ |
1485 | fn fmt(&self, f: &mut Formatter) -> Result { |
1486 | Pointer::fmt(&(*self as *const T), f) | |
1487 | } | |
1488 | } | |
1489 | ||
85aaf69f | 1490 | #[stable(feature = "rust1", since = "1.0.0")] |
7453a54e | 1491 | impl<'a, T: ?Sized> Pointer for &'a T { |
1a4d82fc JJ |
1492 | fn fmt(&self, f: &mut Formatter) -> Result { |
1493 | Pointer::fmt(&(*self as *const T), f) | |
1494 | } | |
1495 | } | |
1496 | ||
85aaf69f | 1497 | #[stable(feature = "rust1", since = "1.0.0")] |
7453a54e | 1498 | impl<'a, T: ?Sized> Pointer for &'a mut T { |
1a4d82fc JJ |
1499 | fn fmt(&self, f: &mut Formatter) -> Result { |
1500 | Pointer::fmt(&(&**self as *const T), f) | |
1501 | } | |
1502 | } | |
1503 | ||
9346a6ac | 1504 | // Common code of floating point Debug and Display. |
d9579d0f AL |
1505 | fn float_to_decimal_common<T>(fmt: &mut Formatter, num: &T, negative_zero: bool) -> Result |
1506 | where T: flt2dec::DecodableFloat | |
1507 | { | |
b039eaaf | 1508 | let force_sign = fmt.sign_plus(); |
d9579d0f AL |
1509 | let sign = match (force_sign, negative_zero) { |
1510 | (false, false) => flt2dec::Sign::Minus, | |
1511 | (false, true) => flt2dec::Sign::MinusRaw, | |
1512 | (true, false) => flt2dec::Sign::MinusPlus, | |
1513 | (true, true) => flt2dec::Sign::MinusPlusRaw, | |
1514 | }; | |
1515 | ||
1516 | let mut buf = [0; 1024]; // enough for f32 and f64 | |
1517 | let mut parts = [flt2dec::Part::Zero(0); 16]; | |
1518 | let formatted = if let Some(precision) = fmt.precision { | |
1519 | flt2dec::to_exact_fixed_str(flt2dec::strategy::grisu::format_exact, *num, sign, | |
1520 | precision, false, &mut buf, &mut parts) | |
1521 | } else { | |
1522 | flt2dec::to_shortest_str(flt2dec::strategy::grisu::format_shortest, *num, sign, | |
1523 | 0, false, &mut buf, &mut parts) | |
1524 | }; | |
1525 | fmt.pad_formatted_parts(&formatted) | |
1526 | } | |
1527 | ||
1528 | // Common code of floating point LowerExp and UpperExp. | |
1529 | fn float_to_exponential_common<T>(fmt: &mut Formatter, num: &T, upper: bool) -> Result | |
1530 | where T: flt2dec::DecodableFloat | |
1531 | { | |
b039eaaf | 1532 | let force_sign = fmt.sign_plus(); |
d9579d0f AL |
1533 | let sign = match force_sign { |
1534 | false => flt2dec::Sign::Minus, | |
1535 | true => flt2dec::Sign::MinusPlus, | |
1536 | }; | |
1537 | ||
1538 | let mut buf = [0; 1024]; // enough for f32 and f64 | |
1539 | let mut parts = [flt2dec::Part::Zero(0); 16]; | |
1540 | let formatted = if let Some(precision) = fmt.precision { | |
1541 | // 1 integral digit + `precision` fractional digits = `precision + 1` total digits | |
1542 | flt2dec::to_exact_exp_str(flt2dec::strategy::grisu::format_exact, *num, sign, | |
1543 | precision + 1, upper, &mut buf, &mut parts) | |
1544 | } else { | |
1545 | flt2dec::to_shortest_exp_str(flt2dec::strategy::grisu::format_shortest, *num, sign, | |
1546 | (0, 0), upper, &mut buf, &mut parts) | |
9346a6ac | 1547 | }; |
d9579d0f | 1548 | fmt.pad_formatted_parts(&formatted) |
9346a6ac AL |
1549 | } |
1550 | ||
1a4d82fc JJ |
1551 | macro_rules! floating { ($ty:ident) => { |
1552 | ||
85aaf69f SL |
1553 | #[stable(feature = "rust1", since = "1.0.0")] |
1554 | impl Debug for $ty { | |
1a4d82fc | 1555 | fn fmt(&self, fmt: &mut Formatter) -> Result { |
d9579d0f | 1556 | float_to_decimal_common(fmt, self, true) |
1a4d82fc JJ |
1557 | } |
1558 | } | |
1559 | ||
85aaf69f SL |
1560 | #[stable(feature = "rust1", since = "1.0.0")] |
1561 | impl Display for $ty { | |
1a4d82fc | 1562 | fn fmt(&self, fmt: &mut Formatter) -> Result { |
d9579d0f | 1563 | float_to_decimal_common(fmt, self, false) |
1a4d82fc JJ |
1564 | } |
1565 | } | |
1566 | ||
85aaf69f | 1567 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1568 | impl LowerExp for $ty { |
1569 | fn fmt(&self, fmt: &mut Formatter) -> Result { | |
d9579d0f | 1570 | float_to_exponential_common(fmt, self, false) |
1a4d82fc JJ |
1571 | } |
1572 | } | |
1573 | ||
85aaf69f | 1574 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1575 | impl UpperExp for $ty { |
1576 | fn fmt(&self, fmt: &mut Formatter) -> Result { | |
d9579d0f | 1577 | float_to_exponential_common(fmt, self, true) |
1a4d82fc JJ |
1578 | } |
1579 | } | |
1580 | } } | |
1581 | floating! { f32 } | |
1582 | floating! { f64 } | |
1583 | ||
85aaf69f | 1584 | // Implementation of Display/Debug for various core types |
1a4d82fc | 1585 | |
85aaf69f SL |
1586 | #[stable(feature = "rust1", since = "1.0.0")] |
1587 | impl<T> Debug for *const T { | |
1a4d82fc JJ |
1588 | fn fmt(&self, f: &mut Formatter) -> Result { Pointer::fmt(self, f) } |
1589 | } | |
85aaf69f SL |
1590 | #[stable(feature = "rust1", since = "1.0.0")] |
1591 | impl<T> Debug for *mut T { | |
1a4d82fc JJ |
1592 | fn fmt(&self, f: &mut Formatter) -> Result { Pointer::fmt(self, f) } |
1593 | } | |
1594 | ||
1595 | macro_rules! peel { | |
1596 | ($name:ident, $($other:ident,)*) => (tuple! { $($other,)* }) | |
1597 | } | |
1598 | ||
1599 | macro_rules! tuple { | |
1600 | () => (); | |
1601 | ( $($name:ident,)+ ) => ( | |
85aaf69f SL |
1602 | #[stable(feature = "rust1", since = "1.0.0")] |
1603 | impl<$($name:Debug),*> Debug for ($($name,)*) { | |
9cc50fc6 | 1604 | #[allow(non_snake_case, unused_assignments, deprecated)] |
1a4d82fc | 1605 | fn fmt(&self, f: &mut Formatter) -> Result { |
c1a9b12d | 1606 | let mut builder = f.debug_tuple(""); |
1a4d82fc | 1607 | let ($(ref $name,)*) = *self; |
1a4d82fc | 1608 | $( |
c1a9b12d | 1609 | builder.field($name); |
1a4d82fc | 1610 | )* |
c1a9b12d | 1611 | |
c1a9b12d | 1612 | builder.finish() |
1a4d82fc JJ |
1613 | } |
1614 | } | |
1615 | peel! { $($name,)* } | |
1616 | ) | |
1617 | } | |
1618 | ||
1619 | tuple! { T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, } | |
1620 | ||
85aaf69f SL |
1621 | #[stable(feature = "rust1", since = "1.0.0")] |
1622 | impl<T: Debug> Debug for [T] { | |
1a4d82fc | 1623 | fn fmt(&self, f: &mut Formatter) -> Result { |
62682a34 | 1624 | f.debug_list().entries(self.iter()).finish() |
1a4d82fc JJ |
1625 | } |
1626 | } | |
1627 | ||
85aaf69f SL |
1628 | #[stable(feature = "rust1", since = "1.0.0")] |
1629 | impl Debug for () { | |
1a4d82fc JJ |
1630 | fn fmt(&self, f: &mut Formatter) -> Result { |
1631 | f.pad("()") | |
1632 | } | |
1633 | } | |
92a42be0 | 1634 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 | 1635 | impl<T: ?Sized> Debug for PhantomData<T> { |
1a4d82fc | 1636 | fn fmt(&self, f: &mut Formatter) -> Result { |
85aaf69f | 1637 | f.pad("PhantomData") |
1a4d82fc JJ |
1638 | } |
1639 | } | |
1640 | ||
85aaf69f SL |
1641 | #[stable(feature = "rust1", since = "1.0.0")] |
1642 | impl<T: Copy + Debug> Debug for Cell<T> { | |
1a4d82fc | 1643 | fn fmt(&self, f: &mut Formatter) -> Result { |
54a0048b SL |
1644 | f.debug_struct("Cell") |
1645 | .field("value", &self.get()) | |
1646 | .finish() | |
1a4d82fc JJ |
1647 | } |
1648 | } | |
1649 | ||
85aaf69f | 1650 | #[stable(feature = "rust1", since = "1.0.0")] |
d9579d0f | 1651 | impl<T: ?Sized + Debug> Debug for RefCell<T> { |
1a4d82fc | 1652 | fn fmt(&self, f: &mut Formatter) -> Result { |
85aaf69f SL |
1653 | match self.borrow_state() { |
1654 | BorrowState::Unused | BorrowState::Reading => { | |
54a0048b SL |
1655 | f.debug_struct("RefCell") |
1656 | .field("value", &self.borrow()) | |
1657 | .finish() | |
1658 | } | |
1659 | BorrowState::Writing => { | |
1660 | f.debug_struct("RefCell") | |
1661 | .field("value", &"<borrowed>") | |
1662 | .finish() | |
85aaf69f | 1663 | } |
85aaf69f | 1664 | } |
1a4d82fc JJ |
1665 | } |
1666 | } | |
1667 | ||
85aaf69f | 1668 | #[stable(feature = "rust1", since = "1.0.0")] |
d9579d0f | 1669 | impl<'b, T: ?Sized + Debug> Debug for Ref<'b, T> { |
1a4d82fc | 1670 | fn fmt(&self, f: &mut Formatter) -> Result { |
85aaf69f | 1671 | Debug::fmt(&**self, f) |
1a4d82fc JJ |
1672 | } |
1673 | } | |
1674 | ||
85aaf69f | 1675 | #[stable(feature = "rust1", since = "1.0.0")] |
d9579d0f | 1676 | impl<'b, T: ?Sized + Debug> Debug for RefMut<'b, T> { |
1a4d82fc | 1677 | fn fmt(&self, f: &mut Formatter) -> Result { |
85aaf69f | 1678 | Debug::fmt(&*(self.deref()), f) |
1a4d82fc JJ |
1679 | } |
1680 | } | |
1681 | ||
54a0048b SL |
1682 | #[stable(feature = "core_impl_debug", since = "1.9.0")] |
1683 | impl<T: ?Sized + Debug> Debug for UnsafeCell<T> { | |
1684 | fn fmt(&self, f: &mut Formatter) -> Result { | |
1685 | f.pad("UnsafeCell") | |
1686 | } | |
1687 | } | |
1688 | ||
1a4d82fc JJ |
1689 | // If you expected tests to be here, look instead at the run-pass/ifmt.rs test, |
1690 | // it's a lot easier than creating all of the rt::Piece structures here. |