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macro_rules! quote {
() => (::proc_macro::TokenStream::new());
($($x:tt)*) => {{
let mut ts = ::proc_macro::TokenStream::new();
let ts_mut = &mut ts;
quote_inner!(ts_mut $($x)*);
ts
}};
}
#[cfg(any(feature = "formatting", feature = "parsing"))]
macro_rules! quote_append {
($ts:ident $($x:tt)*) => {{
quote_inner!($ts $($x)*);
}};
}
macro_rules! quote_group {
({ $($x:tt)* }) => {
::proc_macro::TokenTree::Group(::proc_macro::Group::new(
::proc_macro::Delimiter::Brace,
quote!($($x)*)
))
};
}
macro_rules! sym {
($ts:ident $x:tt $y:tt) => {
$ts.extend([
::proc_macro::TokenTree::from(::proc_macro::Punct::new(
$x,
::proc_macro::Spacing::Joint,
)),
::proc_macro::TokenTree::from(::proc_macro::Punct::new(
$y,
::proc_macro::Spacing::Alone,
)),
]);
};
($ts:ident $x:tt) => {
$ts.extend([::proc_macro::TokenTree::from(::proc_macro::Punct::new(
$x,
::proc_macro::Spacing::Alone,
))]);
};
}
macro_rules! quote_inner {
// Base case
($ts:ident) => {};
// Single or double symbols
($ts:ident :: $($tail:tt)*) => { sym!($ts ':' ':'); quote_inner!($ts $($tail)*); };
($ts:ident .. $($tail:tt)*) => { sym!($ts '.' '.'); quote_inner!($ts $($tail)*); };
($ts:ident : $($tail:tt)*) => { sym!($ts ':'); quote_inner!($ts $($tail)*); };
($ts:ident = $($tail:tt)*) => { sym!($ts '='); quote_inner!($ts $($tail)*); };
($ts:ident ; $($tail:tt)*) => { sym!($ts ';'); quote_inner!($ts $($tail)*); };
($ts:ident , $($tail:tt)*) => { sym!($ts ','); quote_inner!($ts $($tail)*); };
($ts:ident . $($tail:tt)*) => { sym!($ts '.'); quote_inner!($ts $($tail)*); };
($ts:ident & $($tail:tt)*) => { sym!($ts '&'); quote_inner!($ts $($tail)*); };
($ts:ident << $($tail:tt)*) => { sym!($ts '<' '<'); quote_inner!($ts $($tail)*); };
($ts:ident < $($tail:tt)*) => { sym!($ts '<'); quote_inner!($ts $($tail)*); };
($ts:ident >> $($tail:tt)*) => { sym!($ts '>' '>'); quote_inner!($ts $($tail)*); };
($ts:ident > $($tail:tt)*) => { sym!($ts '>'); quote_inner!($ts $($tail)*); };
($ts:ident -> $($tail:tt)*) => { sym!($ts '-' '>'); quote_inner!($ts $($tail)*); };
($ts:ident ? $($tail:tt)*) => { sym!($ts '?'); quote_inner!($ts $($tail)*); };
($ts:ident ! $($tail:tt)*) => { sym!($ts '!'); quote_inner!($ts $($tail)*); };
($ts:ident | $($tail:tt)*) => { sym!($ts '|'); quote_inner!($ts $($tail)*); };
($ts:ident * $($tail:tt)*) => { sym!($ts '*'); quote_inner!($ts $($tail)*); };
($ts:ident + $($tail:tt)*) => { sym!($ts '+'); quote_inner!($ts $($tail)*); };
// Identifier
($ts:ident $i:ident $($tail:tt)*) => {
$ts.extend([::proc_macro::TokenTree::from(::proc_macro::Ident::new(
&stringify!($i),
::proc_macro::Span::mixed_site(),
))]);
quote_inner!($ts $($tail)*);
};
// Literal
($ts:ident 0 $($tail:tt)*) => {
$ts.extend([::proc_macro::TokenTree::from(::proc_macro::Literal::usize_unsuffixed(0))]);
quote_inner!($ts $($tail)*);
};
($ts:ident $l:literal $($tail:tt)*) => {
$ts.extend([::proc_macro::TokenTree::from(::proc_macro::Literal::string(&$l))]);
quote_inner!($ts $($tail)*);
};
// Lifetime
($ts:ident $l:lifetime $($tail:tt)*) => {
$ts.extend([
::proc_macro::TokenTree::from(
::proc_macro::Punct::new('\'', ::proc_macro::Spacing::Joint)
),
::proc_macro::TokenTree::from(::proc_macro::Ident::new(
stringify!($l).trim_start_matches(|c| c == '\''),
::proc_macro::Span::mixed_site(),
)),
]);
quote_inner!($ts $($tail)*);
};
// Groups
($ts:ident ($($inner:tt)*) $($tail:tt)*) => {
$ts.extend([::proc_macro::TokenTree::Group(::proc_macro::Group::new(
::proc_macro::Delimiter::Parenthesis,
quote!($($inner)*)
))]);
quote_inner!($ts $($tail)*);
};
($ts:ident [$($inner:tt)*] $($tail:tt)*) => {
$ts.extend([::proc_macro::TokenTree::Group(::proc_macro::Group::new(
::proc_macro::Delimiter::Bracket,
quote!($($inner)*)
))]);
quote_inner!($ts $($tail)*);
};
($ts:ident {$($inner:tt)*} $($tail:tt)*) => {
$ts.extend([::proc_macro::TokenTree::Group(::proc_macro::Group::new(
::proc_macro::Delimiter::Brace,
quote!($($inner)*)
))]);
quote_inner!($ts $($tail)*);
};
// Interpolated values
// TokenTree by default
($ts:ident #($e:expr) $($tail:tt)*) => {
$ts.extend([$crate::to_tokens::ToTokenTree::into_token_tree($e)]);
quote_inner!($ts $($tail)*);
};
// Allow a TokenStream by request. It's more expensive, so avoid if possible.
($ts:ident #S($e:expr) $($tail:tt)*) => {
$crate::to_tokens::ToTokenStream::append_to($e, $ts);
quote_inner!($ts $($tail)*);
};
}