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macro_rules! ast_struct {
(
[$($attrs_pub:tt)*]
struct $name:ident #full $($rest:tt)*
) => {
#[cfg(feature = "full")]
$($attrs_pub)* struct $name $($rest)*
#[cfg(not(feature = "full"))]
$($attrs_pub)* struct $name {
_noconstruct: ::std::marker::PhantomData<::proc_macro2::Span>,
}
#[cfg(all(not(feature = "full"), feature = "printing"))]
impl ::quote::ToTokens for $name {
fn to_tokens(&self, _: &mut ::proc_macro2::TokenStream) {
unreachable!()
}
}
};
(
[$($attrs_pub:tt)*]
struct $name:ident $($rest:tt)*
) => {
$($attrs_pub)* struct $name $($rest)*
};
($($t:tt)*) => {
strip_attrs_pub!(ast_struct!($($t)*));
};
}
macro_rules! ast_enum {
(
[$($attrs_pub:tt)*]
enum $name:ident #no_visit $($rest:tt)*
) => (
ast_enum!([$($attrs_pub)*] enum $name $($rest)*);
);
(
[$($attrs_pub:tt)*]
enum $name:ident $($rest:tt)*
) => (
$($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 $name:ident #$tag:ident $body:tt
$($remaining:tt)*
) => {
ast_enum!($(#[$enum_attr])* $pub $enum $name #$tag $body);
ast_enum_of_structs_impl!($pub $enum $name $body $($remaining)*);
};
(
$(#[$enum_attr:meta])*
$pub:ident $enum:ident $name:ident $body:tt
$($remaining:tt)*
) => {
ast_enum!($(#[$enum_attr])* $pub $enum $name $body);
ast_enum_of_structs_impl!($pub $enum $name $body $($remaining)*);
};
}
macro_rules! ast_enum_of_structs_impl {
(
$pub:ident $enum:ident $name:ident {
$(
$(#[$variant_attr:meta])*
$variant:ident $( ($($member:ident)::+) )*,
)*
}
$($remaining:tt)*
) => {
check_keyword_matches!(pub $pub);
check_keyword_matches!(enum $enum);
$($(
ast_enum_from_struct!($name::$variant, $($member)::+);
)*)*
#[cfg(feature = "printing")]
generate_to_tokens! {
$($remaining)*
()
tokens
$name { $($variant $($($member)::+)*,)* }
}
};
}
macro_rules! ast_enum_from_struct {
($name:ident::Verbatim, $member:ident) => {};
($name:ident::$variant:ident, crate::private) => {};
($name:ident::$variant:ident, $member:ident) => {
impl From<$member> for $name {
fn from(e: $member) -> $name {
$name::$variant(e)
}
}
};
}
#[cfg(feature = "printing")]
macro_rules! generate_to_tokens {
(do_not_generate_to_tokens $($foo:tt)*) => ();
(($($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) => _e.to_tokens($tokens),)
$tokens $name { $($next)* }
);
};
(($($arms:tt)*) $tokens:ident $name:ident { $variant:ident crate::private, $($next:tt)*}) => {
generate_to_tokens!(
($($arms)* $name::$variant(_) => unreachable!(),)
$tokens $name { $($next)* }
);
};
(($($arms:tt)*) $tokens:ident $name:ident {}) => {
#[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
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) => {};
}