diff options
Diffstat (limited to 'syn-mid/src/macros.rs')
-rw-r--r-- | syn-mid/src/macros.rs | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/syn-mid/src/macros.rs b/syn-mid/src/macros.rs new file mode 100644 index 0000000..87be7b4 --- /dev/null +++ b/syn-mid/src/macros.rs @@ -0,0 +1,107 @@ +macro_rules! ast_struct { + ( + [$($attrs_pub:tt)*] + struct $name:ident $($rest:tt)* + ) => { + #[cfg_attr(feature = "clone-impls", derive(Clone))] + $($attrs_pub)* struct $name $($rest)* + }; + + ($($t:tt)*) => { + strip_attrs_pub!(ast_struct!($($t)*)); + }; +} + +macro_rules! ast_enum { + ( + [$($attrs_pub:tt)*] + enum $name:ident $($rest:tt)* + ) => ( + #[cfg_attr(feature = "clone-impls", derive(Clone))] + $($attrs_pub)* enum $name $($rest)* + ); + + ($($t:tt)*) => { + strip_attrs_pub!(ast_enum!($($t)*)); + }; +} + +macro_rules! ast_enum_of_structs { + ( + $(#[$enum_attr:meta])* + $pub:ident $enum:ident $name:ident $body:tt + ) => { + ast_enum!($(#[$enum_attr])* $pub $enum $name $body); + ast_enum_of_structs_impl!($pub $enum $name $body); + }; +} + +macro_rules! ast_enum_of_structs_impl { + ( + $pub:ident $enum:ident $name:ident { + $( + $(#[$variant_attr:meta])* + $variant:ident $( ($member:ident) )*, + )* + } + ) => { + check_keyword_matches!(pub $pub); + check_keyword_matches!(enum $enum); + + $( + $( + impl From<$member> for $name { + fn from(e: $member) -> $name { + $name::$variant(e) + } + } + )* + )* + + generate_to_tokens! { + () + tokens + $name { $($variant $($member)*,)* } + } + }; +} + +macro_rules! generate_to_tokens { + (($($arms:tt)*) $tokens:ident $name:ident { $variant:ident, $($next:tt)*}) => { + generate_to_tokens!( + ($($arms)* $name::$variant => {}) + $tokens $name { $($next)* } + ); + }; + + (($($arms:tt)*) $tokens:ident $name:ident { $variant:ident $member:ident, $($next:tt)*}) => { + generate_to_tokens!( + ($($arms)* $name::$variant(_e) => quote::ToTokens::to_tokens(_e, $tokens),) + $tokens $name { $($next)* } + ); + }; + + (($($arms:tt)*) $tokens:ident $name:ident {}) => { + impl quote::ToTokens for $name { + fn to_tokens(&self, $tokens: &mut proc_macro2::TokenStream) { + match self { + $($arms)* + } + } + } + }; +} + +macro_rules! strip_attrs_pub { + ($mac:ident!($(#[$m:meta])* $pub:ident $($t:tt)*)) => { + check_keyword_matches!(pub $pub); + + $mac!([$(#[$m])* $pub] $($t)*); + }; +} + +macro_rules! check_keyword_matches { + (struct struct) => {}; + (enum enum) => {}; + (pub pub) => {}; +} |