squiid/rust
1
0
Fork 0
Code Issues Pull requests Projects Activity

use PatIdentRenamer for match bindings

Browse source
This commit is contained in:
John Clements 2014-07-04 12:15:24 -07:00
parent 35175f015f
commit 6bee3c87c9
1 changed files with 5 additions and 10 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

15
src/libsyntax/ext/expand.rs
View file

@ -667,19 +667,14 @@ fn expand_arm(arm: &ast::Arm, fld: &mut MacroExpander) -> ast::Arm {
// code duplicated from 'let', above. Perhaps this can be lifted
// into a separate function:
let idents = pattern_bindings(*first_pat);
let mut new_pending_renames =
let new_pending_renames =
idents.iter().map(|id| (*id,fresh_name(id))).collect();
// rewrite all of the patterns using the new names (the old
// ones have already been applied). Note that we depend here
// on the guarantee that after expansion, there can't be any
// Path expressions (a.k.a. varrefs) left in the pattern. If
// this were false, we'd need to apply this renaming only to
// the bindings, and not to the varrefs, using a more targeted
// fold-er.
let mut rename_fld = IdentRenamer{renames:&mut new_pending_renames};
// apply the renaming, but only to the PatIdents:
let mut rename_pats_fld = PatIdentRenamer{renames:&new_pending_renames};
let rewritten_pats =
expanded_pats.iter().map(|pat| rename_fld.fold_pat(*pat)).collect();
expanded_pats.iter().map(|pat| rename_pats_fld.fold_pat(*pat)).collect();
// apply renaming and then expansion to the guard and the body:
let mut rename_fld = IdentRenamer{renames:&new_pending_renames};
let rewritten_guard =
arm.guard.map(|g| fld.fold_expr(rename_fld.fold_expr(g)));
let rewritten_body = fld.fold_expr(rename_fld.fold_expr(arm.body));