enum_table/
macros.rs

1/// A macro to create an `EnumTable` for a given enumeration and value type.
2///
3/// # Arguments
4///
5/// * `$variant` - The enumeration type that implements the `Enumable` trait.
6/// * `$value` - The type of values to be associated with each enumeration variant.
7/// * `$count` - The number of variants in the enumeration.
8/// * `$variable` - The variable name to use in the closure for each variant.
9/// * `$($tt:tt)*` - The closure that maps each variant to a value.
10///
11/// # Example
12///
13/// ```rust
14/// use enum_table::{EnumTable, Enumable, et};
15///
16/// enum Test {
17///     A,
18///     B,
19///     C,
20/// }
21///
22/// impl enum_table::Enumable for Test {
23///     const VARIANTS: &'static [Self] = &[Test::A, Test::B, Test::C];
24/// }
25///
26/// const TABLE: EnumTable<Test, &'static str, { Test::COUNT }> =
27///     et!(Test, &'static str, |t| match t {
28///         Test::A => "A",
29///         Test::B => "B",
30///         Test::C => "C",
31///     });
32///
33/// assert_eq!(TABLE.get(&Test::A), &"A");
34/// assert_eq!(TABLE.get(&Test::B), &"B");
35/// assert_eq!(TABLE.get(&Test::C), &"C");
36///
37#[macro_export]
38macro_rules! et {
39    ($variant:ty, $value:ty, |$variable:ident| $($tt:tt)*) => {
40        {
41            let mut builder = $crate::builder::EnumTableBuilder::<$variant, $value, { <$variant as $crate::Enumable>::COUNT }>::new();
42
43            let mut i = 0;
44            while i < builder.len() {
45                let $variable = &<$variant as $crate::Enumable>::VARIANTS[i];
46                builder.push(
47                    $variable,
48                    $($tt)*
49                );
50                i += 1;
51            }
52
53            builder.build_to()
54        }
55    };
56}
57
58#[cfg(test)]
59mod tests {
60    use crate::{EnumTable, Enumable};
61
62    #[test]
63    fn et_macro() {
64        #[derive(Enumable)]
65        enum Test {
66            A,
67            B,
68            C,
69        }
70
71        const TABLE: EnumTable<Test, &'static str, { Test::COUNT }> =
72            et!(Test, &'static str, |t| match t {
73                Test::A => "A",
74                Test::B => "B",
75                Test::C => "C",
76            });
77
78        assert_eq!(TABLE.get(&Test::A), &"A");
79        assert_eq!(TABLE.get(&Test::B), &"B");
80        assert_eq!(TABLE.get(&Test::C), &"C");
81    }
82}
enum_table/macros.rs

enum_table/
macros.rs
