src/tools/rust-analyzer/crates/ide-assists/src/handlers/number_representation.rs

   1 use syntax::{ast, ast::Radix, AstToken};
   2
   3 use crate::{AssistContext, AssistId, AssistKind, Assists, GroupLabel};
   4
   5 const MIN_NUMBER_OF_DIGITS_TO_FORMAT: usize = 5;
   6
   7 // Assist: reformat_number_literal
   8 //
   9 // Adds or removes separators from integer literal.
  10 //
  11 // ```
  12 // const _: i32 = 1012345$0;
  13 // ```
  14 // ->
  15 // ```
  16 // const _: i32 = 1_012_345;
  17 // ```
  18 pub(crate) fn reformat_number_literal(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<()> {
  19     let literal = ctx.find_node_at_offset::<ast::Literal>()?;
  20     let literal = match literal.kind() {
  21         ast::LiteralKind::IntNumber(it) => it,
  22         _ => return None,
  23     };
  24
  25     let text = literal.text();
  26     if text.contains('_') {
  27         return remove_separators(acc, literal);
  28     }
  29
  30     let (prefix, value, suffix) = literal.split_into_parts();
  31     if value.len() < MIN_NUMBER_OF_DIGITS_TO_FORMAT {
  32         return None;
  33     }
  34
  35     let radix = literal.radix();
  36     let mut converted = prefix.to_string();
  37     converted.push_str(&add_group_separators(value, group_size(radix)));
  38     converted.push_str(suffix);
  39
  40     let group_id = GroupLabel("Reformat number literal".into());
  41     let label = format!("Convert {} to {}", literal, converted);
  42     let range = literal.syntax().text_range();
  43     acc.add_group(
  44         &group_id,
  45         AssistId("reformat_number_literal", AssistKind::RefactorInline),
  46         label,
  47         range,
  48         |builder| builder.replace(range, converted),
  49     )
  50 }
  51
  52 fn remove_separators(acc: &mut Assists, literal: ast::IntNumber) -> Option<()> {
  53     let group_id = GroupLabel("Reformat number literal".into());
  54     let range = literal.syntax().text_range();
  55     acc.add_group(
  56         &group_id,
  57         AssistId("reformat_number_literal", AssistKind::RefactorInline),
  58         "Remove digit separators",
  59         range,
  60         |builder| builder.replace(range, literal.text().replace('_', "")),
  61     )
  62 }
  63
  64 const fn group_size(r: Radix) -> usize {
  65     match r {
  66         Radix::Binary => 4,
  67         Radix::Octal => 3,
  68         Radix::Decimal => 3,
  69         Radix::Hexadecimal => 4,
  70     }
  71 }
  72
  73 fn add_group_separators(s: &str, group_size: usize) -> String {
  74     let mut chars = Vec::new();
  75     for (i, ch) in s.chars().filter(|&ch| ch != '_').rev().enumerate() {
  76         if i > 0 && i % group_size == 0 {
  77             chars.push('_');
  78         }
  79         chars.push(ch);
  80     }
  81
  82     chars.into_iter().rev().collect()
  83 }
  84
  85 #[cfg(test)]
  86 mod tests {
  87     use crate::tests::{check_assist_by_label, check_assist_not_applicable, check_assist_target};
  88
  89     use super::*;
  90
  91     #[test]
  92     fn group_separators() {
  93         let cases = vec![
  94             ("", 4, ""),
  95             ("1", 4, "1"),
  96             ("12", 4, "12"),
  97             ("123", 4, "123"),
  98             ("1234", 4, "1234"),
  99             ("12345", 4, "1_2345"),
 100             ("123456", 4, "12_3456"),
 101             ("1234567", 4, "123_4567"),
 102             ("12345678", 4, "1234_5678"),
 103             ("123456789", 4, "1_2345_6789"),
 104             ("1234567890", 4, "12_3456_7890"),
 105             ("1_2_3_4_5_6_7_8_9_0_", 4, "12_3456_7890"),
 106             ("1234567890", 3, "1_234_567_890"),
 107             ("1234567890", 2, "12_34_56_78_90"),
 108             ("1234567890", 1, "1_2_3_4_5_6_7_8_9_0"),
 109         ];
 110
 111         for case in cases {
 112             let (input, group_size, expected) = case;
 113             assert_eq!(add_group_separators(input, group_size), expected)
 114         }
 115     }
 116
 117     #[test]
 118     fn good_targets() {
 119         let cases = vec![
 120             ("const _: i32 = 0b11111$0", "0b11111"),
 121             ("const _: i32 = 0o77777$0;", "0o77777"),
 122             ("const _: i32 = 10000$0;", "10000"),
 123             ("const _: i32 = 0xFFFFF$0;", "0xFFFFF"),
 124             ("const _: i32 = 10000i32$0;", "10000i32"),
 125             ("const _: i32 = 0b_10_0i32$0;", "0b_10_0i32"),
 126         ];
 127
 128         for case in cases {
 129             check_assist_target(reformat_number_literal, case.0, case.1);
 130         }
 131     }
 132
 133     #[test]
 134     fn bad_targets() {
 135         let cases = vec![
 136             "const _: i32 = 0b111$0",
 137             "const _: i32 = 0b1111$0",
 138             "const _: i32 = 0o77$0;",
 139             "const _: i32 = 0o777$0;",
 140             "const _: i32 = 10$0;",
 141             "const _: i32 = 999$0;",
 142             "const _: i32 = 0xFF$0;",
 143             "const _: i32 = 0xFFFF$0;",
 144         ];
 145
 146         for case in cases {
 147             check_assist_not_applicable(reformat_number_literal, case);
 148         }
 149     }
 150
 151     #[test]
 152     fn labels() {
 153         let cases = vec![
 154             ("const _: i32 = 10000$0", "const _: i32 = 10_000", "Convert 10000 to 10_000"),
 155             (
 156                 "const _: i32 = 0xFF0000$0;",
 157                 "const _: i32 = 0xFF_0000;",
 158                 "Convert 0xFF0000 to 0xFF_0000",
 159             ),
 160             (
 161                 "const _: i32 = 0b11111111$0;",
 162                 "const _: i32 = 0b1111_1111;",
 163                 "Convert 0b11111111 to 0b1111_1111",
 164             ),
 165             (
 166                 "const _: i32 = 0o377211$0;",
 167                 "const _: i32 = 0o377_211;",
 168                 "Convert 0o377211 to 0o377_211",
 169             ),
 170             (
 171                 "const _: i32 = 10000i32$0;",
 172                 "const _: i32 = 10_000i32;",
 173                 "Convert 10000i32 to 10_000i32",
 174             ),
 175             ("const _: i32 = 1_0_0_0_i32$0;", "const _: i32 = 1000i32;", "Remove digit separators"),
 176         ];
 177
 178         for case in cases {
 179             let (before, after, label) = case;
 180             check_assist_by_label(reformat_number_literal, before, after, label);
 181         }
 182     }
 183 }