vendor/heck/src/snake.rs

   1 use std::fmt;
   2
   3 use crate::{lowercase, transform};
   4
   5 /// This trait defines a snake case conversion.
   6 ///
   7 /// In snake_case, word boundaries are indicated by underscores.
   8 ///
   9 /// ## Example:
  10 ///
  11 /// ```rust
  12 /// use heck::ToSnakeCase;
  13 ///
  14 /// let sentence = "We carry a new world here, in our hearts.";
  15 /// assert_eq!(sentence.to_snake_case(), "we_carry_a_new_world_here_in_our_hearts");
  16 /// ```
  17 pub trait ToSnakeCase: ToOwned {
  18     /// Convert this type to snake case.
  19     fn to_snake_case(&self) -> Self::Owned;
  20 }
  21
  22 /// Oh heck, SnekCase is an alias for ToSnakeCase. See ToSnakeCase for
  23 /// more documentation.
  24 pub trait ToSnekCase: ToOwned {
  25     /// Convert this type to snek case.
  26     fn to_snek_case(&self) -> Self::Owned;
  27 }
  28
  29 impl<T: ?Sized + ToSnakeCase> ToSnekCase for T {
  30     fn to_snek_case(&self) -> Self::Owned {
  31         self.to_snake_case()
  32     }
  33 }
  34
  35 impl ToSnakeCase for str {
  36     fn to_snake_case(&self) -> String {
  37         AsSnakeCase(self).to_string()
  38     }
  39 }
  40
  41 /// This wrapper performs a snake case conversion in [`fmt::Display`].
  42 ///
  43 /// ## Example:
  44 ///
  45 /// ```
  46 /// use heck::AsSnakeCase;
  47 ///
  48 /// let sentence = "We carry a new world here, in our hearts.";
  49 /// assert_eq!(format!("{}", AsSnakeCase(sentence)), "we_carry_a_new_world_here_in_our_hearts");
  50 /// ```
  51 pub struct AsSnakeCase<T: AsRef<str>>(pub T);
  52
  53 impl<T: AsRef<str>> fmt::Display for AsSnakeCase<T> {
  54     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  55         transform(self.0.as_ref(), lowercase, |f| write!(f, "_"), f)
  56     }
  57 }
  58
  59 #[cfg(test)]
  60 mod tests {
  61     use super::ToSnakeCase;
  62
  63     macro_rules! t {
  64         ($t:ident : $s1:expr => $s2:expr) => {
  65             #[test]
  66             fn $t() {
  67                 assert_eq!($s1.to_snake_case(), $s2)
  68             }
  69         };
  70     }
  71
  72     t!(test1: "CamelCase" => "camel_case");
  73     t!(test2: "This is Human case." => "this_is_human_case");
  74     t!(test3: "MixedUP CamelCase, with some Spaces" => "mixed_up_camel_case_with_some_spaces");
  75     t!(test4: "mixed_up_ snake_case with some _spaces" => "mixed_up_snake_case_with_some_spaces");
  76     t!(test5: "kebab-case" => "kebab_case");
  77     t!(test6: "SHOUTY_SNAKE_CASE" => "shouty_snake_case");
  78     t!(test7: "snake_case" => "snake_case");
  79     t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "this_contains_all_kinds_of_word_boundaries");
  80     #[cfg(feature = "unicode")]
  81     t!(test9: "XΣXΣ baﬄe" => "xσxς_baﬄe");
  82     t!(test10: "XMLHttpRequest" => "xml_http_request");
  83     t!(test11: "FIELD_NAME11" => "field_name11");
  84     t!(test12: "99BOTTLES" => "99bottles");
  85     t!(test13: "FieldNamE11" => "field_nam_e11");
  86
  87     t!(test14: "abc123def456" => "abc123def456");
  88     t!(test16: "abc123DEF456" => "abc123_def456");
  89     t!(test17: "abc123Def456" => "abc123_def456");
  90     t!(test18: "abc123DEf456" => "abc123_d_ef456");
  91     t!(test19: "ABC123def456" => "abc123def456");
  92     t!(test20: "ABC123DEF456" => "abc123def456");
  93     t!(test21: "ABC123Def456" => "abc123_def456");
  94     t!(test22: "ABC123DEf456" => "abc123d_ef456");
  95     t!(test23: "ABC123dEEf456FOO" => "abc123d_e_ef456_foo");
  96     t!(test24: "abcDEF" => "abc_def");
  97     t!(test25: "ABcDE" => "a_bc_de");
  98 }