From 92113489893105d5432df2fd8f727fa2ca8cec51 Mon Sep 17 00:00:00 2001
From: Austin Seipp <as@hacks.yi.org>
Date: Mon, 9 Jan 2012 09:42:07 -0600
Subject: [PATCH] Make the parser accept 'if' as an alternative to 'when' in
alt patterns.
Also fix the pretty printer, making it output 'if' instead of 'when'.
Issue #1396
---
src/comp/syntax/parse/parser.rs | 6 +++++-
src/comp/syntax/print/pprust.rs | 2 +-
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/src/comp/syntax/parse/parser.rs b/src/comp/syntax/parse/parser.rs
index 6a59b395ab4..2b45115f5b9 100644
--- a/src/comp/syntax/parse/parser.rs
+++ b/src/comp/syntax/parse/parser.rs
@@ -1389,7 +1389,11 @@ fn parse_alt_expr(p: parser) -> @ast::expr {
while p.peek() != token::RBRACE {
let pats = parse_pats(p);
let guard = none;
- if eat_word(p, "when") { guard = some(parse_expr(p)); }
+ if eat_word(p, "when") {
+ guard = some(parse_expr(p));
+ } else if eat_word(p, "if") {
+ guard = some(parse_expr(p));
+ }
let blk = parse_block(p);
arms += [{pats: pats, guard: guard, body: blk}];
}
diff --git a/src/comp/syntax/print/pprust.rs b/src/comp/syntax/print/pprust.rs
index 3e9eab79281..b4a47a8db38 100644
--- a/src/comp/syntax/print/pprust.rs
+++ b/src/comp/syntax/print/pprust.rs
@@ -843,7 +843,7 @@ fn print_expr(s: ps, &&expr: @ast::expr) {
}
space(s.s);
alt arm.guard {
- some(e) { word_space(s, "when"); print_expr(s, e); space(s.s); }
+ some(e) { word_space(s, "if"); print_expr(s, e); space(s.s); }
none. { }
}
print_possibly_embedded_block(s, arm.body, block_normal,