vendor/macro-utils/src/tern_python.rs

   1 // MIT License
   2 //
   3 // Copyright (c) 2018 Guillaume Gomez
   4 //
   5 // Permission is hereby granted, free of charge, to any person obtaining a copy
   6 // of this software and associated documentation files (the "Software"), to deal
   7 // in the Software without restriction, including without limitation the rights
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   9 // copies of the Software, and to permit persons to whom the Software is
  10 // furnished to do so, subject to the following conditions:
  11 //
  12 // The above copyright notice and this permission notice shall be included in all
  13 // copies or substantial portions of the Software.
  14 //
  15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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  20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21 // SOFTWARE.
  22
  23 /// You miss Python-like ternary conditions? Why not having them in Rust then?
  24 ///
  25 /// ```
  26 /// # #[macro_use] extern crate macro_utils;
  27 /// let y = 4;
  28 /// let x = tern_python! { { "it's even" } if (y & 1 == 0) else { "it's odd" } };
  29 ///
  30 /// println!("{} is {}", y, x);
  31 /// ```
  32 #[macro_export]
  33 macro_rules! tern_python {
  34     ({ $if_expr:expr } if ($cond:expr) else { $else_expr:expr }) => {
  35         if $cond {
  36             $if_expr
  37         } else {
  38             $else_expr
  39         }
  40     };
  41 }
  42
  43 /// The same as [`tern_python`] macro but shorter:
  44 ///
  45 /// ```
  46 /// # #[macro_use] extern crate macro_utils;
  47 /// let y = 4;
  48 /// let x = tern_py! { { "it's even" } if (y & 1 == 0) else { "it's odd" } };
  49 ///
  50 /// println!("{} is {}", y, x);
  51 /// ```
  52 ///
  53 /// [`tern_python`]: macro.tern_python.html
  54 #[macro_export]
  55 macro_rules! tern_py {
  56     ({ $if_expr:expr } if ($cond:expr) else { $else_expr:expr }) => {
  57         if $cond {
  58             $if_expr
  59         } else {
  60             $else_expr
  61         }
  62     };
  63 }
  64
  65 #[test]
  66 fn tern_python() {
  67     let y = 4;
  68     let x = tern_python! { { "it's even" } if (y & 1 == 0) else { "it's odd" } };
  69
  70     assert_eq!(x, "it's even");
  71
  72     let x = tern_py! { { "it's even" } if (y & 1 == 0) else { "it's odd" } };
  73
  74     assert_eq!(x, "it's even");
  75 }