bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Add Span and separate open/close delims to TTDelim

Browse source 
This came up when working [on the gl-rs generator extension](990383de80/src/gl_generator/lib.rs (L135-L146)).

The new definition of  `TTDelim` adds an associated `Span` that covers the whole token tree and enforces the invariant that a delimited sequence of token trees must have an opening and closing delimiter.

A `get_span` method has also been added to `TokenTree` type to make it easier to implement better error messages for syntax extensions.
This commit is contained in:
Brendan Zabarauskas 2014-10-22 16:37:20 +11:00
parent 80e5fe1a56
commit 971d776aa5
9 changed files with 135 additions and 88 deletions
Download patch file Download diff file Expand all files Collapse all files

36
src/libsyntax/parse/parser.rs
View file

@ -48,7 +48,7 @@ use ast::{StmtExpr, StmtSemi, StmtMac, StructDef, StructField};
use ast::{StructVariantKind, BiSub};
use ast::StrStyle;
use ast::{SelfExplicit, SelfRegion, SelfStatic, SelfValue};
use ast::{TokenTree, TraitItem, TraitRef, TTDelim, TTSeq, TTTok};
use ast::{Delimiter, TokenTree, TraitItem, TraitRef, TTDelim, TTSeq, TTTok};
use ast::{TTNonterminal, TupleVariantKind, Ty, Ty_, TyBot};
use ast::{TypeField, TyFixedLengthVec, TyClosure, TyProc, TyBareFn};
use ast::{TyTypeof, TyInfer, TypeMethod};
@ -2574,16 +2574,11 @@ impl<'a> Parser<'a> {
}
}
_ => {
parse_any_tt_tok(p)
TTTok(p.span, p.bump_and_get())
}
}
}
// turn the next token into a TTTok:
fn parse_any_tt_tok(p: &mut Parser) -> TokenTree {
TTTok(p.span, p.bump_and_get())
}
match (&self.token, token::close_delimiter_for(&self.token)) {
(&token::EOF, _) => {
let open_braces = self.open_braces.clone();
@ -2595,21 +2590,32 @@ impl<'a> Parser<'a> {
self.fatal("this file contains an un-closed delimiter ");
}
(_, Some(close_delim)) => {
// The span for beginning of the delimited section
let pre_span = self.span;
// Parse the open delimiter.
self.open_braces.push(self.span);
let mut result = vec!(parse_any_tt_tok(self));
let open = Delimiter {
span: self.span,
token: self.bump_and_get(),
};
let trees =
self.parse_seq_to_before_end(&close_delim,
seq_sep_none(),
|p| p.parse_token_tree());
result.extend(trees.into_iter());
// Parse the token trees within the delimeters
let tts = self.parse_seq_to_before_end(
&close_delim, seq_sep_none(), |p| p.parse_token_tree()
);
// Parse the close delimiter.
result.push(parse_any_tt_tok(self));
let close = Delimiter {
span: self.span,
token: self.bump_and_get(),
};
self.open_braces.pop().unwrap();
TTDelim(Rc::new(result))
// Expand to cover the entire delimited token tree
let span = Span { hi: self.span.hi, ..pre_span };
TTDelim(span, open, Rc::new(tts), close)
}
_ => parse_non_delim_tt_tok(self)
}