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Merge pull request #55 from alexcrichton/quote-spanned
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Add a `quote_spanned!` macro
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@dtolnay
dtolnay authored Nov 21, 2017
2 parents 67a9d9f + 3434506 commit 07deeb5
Showing 1 changed file with 49 additions and 39 deletions.
88 changes: 49 additions & 39 deletions src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -70,14 +70,17 @@ pub use to_tokens::{ToTokens, ByteStr};
pub mod __rt {
pub use proc_macro2::*;

pub fn parse(tokens: &mut ::Tokens, s: &str) {
pub fn parse(tokens: &mut ::Tokens, span: Span, s: &str) {
let s: TokenStream = s.parse().expect("invalid token stream");
tokens.append_all(s.into_iter());
tokens.append_all(s.into_iter().map(|mut t| {
t.span = span;
t
}));
}

pub fn append_kind(tokens: &mut ::Tokens, kind: TokenNode) {
pub fn append_kind(tokens: &mut ::Tokens, span: Span, kind: TokenNode) {
tokens.append(TokenTree {
span: Default::default(),
span: span,
kind: kind,
})
}
Expand All @@ -86,14 +89,17 @@ pub mod __rt {
/// The whole point.
#[macro_export]
macro_rules! quote {
() => {
$crate::Tokens::new()
};
($($tt:tt)*) => (quote_spanned!($crate::__rt::Span::default(), $($tt)*));
}

($($tt:tt)+) => {
/// Same as `quote!` above, but all generated tokens will use the span provided
#[macro_export]
macro_rules! quote_spanned {
($span:expr, $($tt:tt)*) => {
{
let mut _s = $crate::Tokens::new();
quote_each_token!(_s $($tt)*);
let _span = $span;
quote_each_token!(_s _span $($tt)*);
_s
}
};
Expand Down Expand Up @@ -200,78 +206,82 @@ macro_rules! multi_zip_expr {
#[macro_export]
#[doc(hidden)]
macro_rules! quote_each_token {
($tokens:ident) => {};
($tokens:ident $span:ident) => {};

($tokens:ident # ! $($rest:tt)*) => {
quote_each_token!($tokens #);
quote_each_token!($tokens !);
quote_each_token!($tokens $($rest)*);
($tokens:ident $span:ident # ! $($rest:tt)*) => {
quote_each_token!($tokens $span #);
quote_each_token!($tokens $span !);
quote_each_token!($tokens $span $($rest)*);
};

($tokens:ident # ( $($inner:tt)* ) * $($rest:tt)*) => {
($tokens:ident $span:ident # ( $($inner:tt)* ) * $($rest:tt)*) => {
for pounded_var_names!(nested_tuples_pat () $($inner)*)
in pounded_var_names!(multi_zip_expr () $($inner)*) {
quote_each_token!($tokens $($inner)*);
quote_each_token!($tokens $span $($inner)*);
}
quote_each_token!($tokens $($rest)*);
quote_each_token!($tokens $span $($rest)*);
};

($tokens:ident # ( $($inner:tt)* ) $sep:tt * $($rest:tt)*) => {
($tokens:ident $span:ident # ( $($inner:tt)* ) $sep:tt * $($rest:tt)*) => {
for (_i, pounded_var_names!(nested_tuples_pat () $($inner)*))
in pounded_var_names!(multi_zip_expr () $($inner)*).into_iter().enumerate() {
if _i > 0 {
quote_each_token!($tokens $sep);
quote_each_token!($tokens $span $sep);
}
quote_each_token!($tokens $($inner)*);
quote_each_token!($tokens $span $($inner)*);
}
quote_each_token!($tokens $($rest)*);
quote_each_token!($tokens $span $($rest)*);
};

($tokens:ident # [ $($inner:tt)* ] $($rest:tt)*) => {
quote_each_token!($tokens #);
($tokens:ident $span:ident # [ $($inner:tt)* ] $($rest:tt)*) => {
quote_each_token!($tokens $span #);
$crate::__rt::append_kind(&mut $tokens,
$span,
$crate::__rt::TokenNode::Group(
$crate::__rt::Delimiter::Bracket,
quote! { $($inner)* }.into()
quote_spanned! { $span, $($inner)* }.into()
));
quote_each_token!($tokens $($rest)*);
quote_each_token!($tokens $span $($rest)*);
};

($tokens:ident # $first:ident $($rest:tt)*) => {
($tokens:ident $span:ident # $first:ident $($rest:tt)*) => {
$crate::ToTokens::to_tokens(&$first, &mut $tokens);
quote_each_token!($tokens $($rest)*);
quote_each_token!($tokens $span $($rest)*);
};

($tokens:ident ( $($first:tt)* ) $($rest:tt)*) => {
($tokens:ident $span:ident ( $($first:tt)* ) $($rest:tt)*) => {
$crate::__rt::append_kind(&mut $tokens,
$span,
$crate::__rt::TokenNode::Group(
$crate::__rt::Delimiter::Parenthesis,
quote! { $($first)* }.into()
quote_spanned! { $span, $($first)* }.into()
));
quote_each_token!($tokens $($rest)*);
quote_each_token!($tokens $span $($rest)*);
};

($tokens:ident [ $($first:tt)* ] $($rest:tt)*) => {
($tokens:ident $span:ident [ $($first:tt)* ] $($rest:tt)*) => {
$crate::__rt::append_kind(&mut $tokens,
$span,
$crate::__rt::TokenNode::Group(
$crate::__rt::Delimiter::Bracket,
quote! { $($first)* }.into()
quote_spanned! { $span, $($first)* }.into()
));
quote_each_token!($tokens $($rest)*);
quote_each_token!($tokens $span $($rest)*);
};

($tokens:ident { $($first:tt)* } $($rest:tt)*) => {
($tokens:ident $span:ident { $($first:tt)* } $($rest:tt)*) => {
$crate::__rt::append_kind(&mut $tokens,
$span,
$crate::__rt::TokenNode::Group(
$crate::__rt::Delimiter::Brace,
quote! { $($first)* }.into()
quote_spanned! { $span, $($first)* }.into()
));
quote_each_token!($tokens $($rest)*);
quote_each_token!($tokens $span $($rest)*);
};

($tokens:ident $first:tt $($rest:tt)*) => {
($tokens:ident $span:ident $first:tt $($rest:tt)*) => {
// TODO: this seems slow... special case some `:tt` arguments?
$crate::__rt::parse(&mut $tokens, stringify!($first));
quote_each_token!($tokens $($rest)*);
$crate::__rt::parse(&mut $tokens, $span, stringify!($first));
quote_each_token!($tokens $span $($rest)*);
};
}

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