From 214c32393a9d28436dd782c9ea6e3e32d3baba2e Mon Sep 17 00:00:00 2001
From: Brian Anderson <andersrb@gmail.com>
Date: Sun, 30 Jan 2011 14:15:22 -0500
Subject: Teach rustc to parse 'else if'

---
 src/comp/front/parser.rs | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

(limited to 'src/comp/front')

diff --git a/src/comp/front/parser.rs b/src/comp/front/parser.rs
index bef37a3c..fbed877f 100644
--- a/src/comp/front/parser.rs
+++ b/src/comp/front/parser.rs
@@ -895,8 +895,7 @@ impure fn parse_if_expr(parser p) -> @ast.expr {
     hi = thn.span;
     alt (p.peek()) {
         case (token.ELSE) {
-            p.bump();
-            auto eblk = parse_block(p);
+            auto eblk = parse_else_block(p);
             els = some(eblk);
             hi = eblk.span;
         }
@@ -905,6 +904,21 @@ impure fn parse_if_expr(parser p) -> @ast.expr {
     ret @spanned(lo, hi, ast.expr_if(cond, thn, els, ast.ann_none));
 }
 
+impure fn parse_else_block(parser p) -> ast.block {
+    expect(p, token.ELSE);
+    alt (p.peek()) {
+        case (token.IF) {
+            let vec[@ast.stmt] stmts = vec();
+            auto ifexpr = parse_if_expr(p);
+            auto bloc = index_block(stmts, some(ifexpr));
+            ret spanned(ifexpr.span, ifexpr.span, bloc);
+        }
+        case (_) {
+            ret parse_block(p);
+        }
+    }
+}
+
 impure fn parse_head_local(parser p) -> @ast.decl {
     auto lo = p.get_span();
     let @ast.local local;
-- 
cgit v1.2.3


From 3fedb18c0af0bd9fa5e4973936003c0b57e4d3e8 Mon Sep 17 00:00:00 2001
From: Brian Anderson <andersrb@gmail.com>
Date: Mon, 31 Jan 2011 23:06:02 -0500
Subject: Allow the else part of an expr_if to be either expr_if or expr_block

---
 src/comp/front/ast.rs    |  2 +-
 src/comp/front/parser.rs | 19 +++++++++----------
 2 files changed, 10 insertions(+), 11 deletions(-)

(limited to 'src/comp/front')

diff --git a/src/comp/front/ast.rs b/src/comp/front/ast.rs
index 10bcd5c4..fb068dba 100644
--- a/src/comp/front/ast.rs
+++ b/src/comp/front/ast.rs
@@ -149,7 +149,7 @@ tag expr_ {
     expr_unary(unop, @expr, ann);
     expr_lit(@lit, ann);
     expr_cast(@expr, @ty, ann);
-    expr_if(@expr, block, option.t[block], ann);
+    expr_if(@expr, block, option.t[@expr], ann);
     expr_while(@expr, block, ann);
     expr_for(@decl, @expr, block, ann);
     expr_do_while(block, @expr, ann);
diff --git a/src/comp/front/parser.rs b/src/comp/front/parser.rs
index fbed877f..e629683c 100644
--- a/src/comp/front/parser.rs
+++ b/src/comp/front/parser.rs
@@ -891,30 +891,29 @@ impure fn parse_if_expr(parser p) -> @ast.expr {
     auto cond = parse_expr(p);
     expect(p, token.RPAREN);
     auto thn = parse_block(p);
-    let option.t[ast.block] els = none[ast.block];
+    let option.t[@ast.expr] els = none[@ast.expr];
     hi = thn.span;
     alt (p.peek()) {
         case (token.ELSE) {
-            auto eblk = parse_else_block(p);
-            els = some(eblk);
-            hi = eblk.span;
+            auto elexpr = parse_else_expr(p);
+            els = some(elexpr);
+            hi = elexpr.span;
         }
         case (_) { /* fall through */ }
     }
     ret @spanned(lo, hi, ast.expr_if(cond, thn, els, ast.ann_none));
 }
 
-impure fn parse_else_block(parser p) -> ast.block {
+impure fn parse_else_expr(parser p) -> @ast.expr {
     expect(p, token.ELSE);
     alt (p.peek()) {
         case (token.IF) {
-            let vec[@ast.stmt] stmts = vec();
-            auto ifexpr = parse_if_expr(p);
-            auto bloc = index_block(stmts, some(ifexpr));
-            ret spanned(ifexpr.span, ifexpr.span, bloc);
+            ret parse_if_expr(p);
         }
         case (_) {
-            ret parse_block(p);
+            auto blk = parse_block(p);
+            ret @spanned(blk.span, blk.span,
+                         ast.expr_block(blk, ast.ann_none));
         }
     }
 }
-- 
cgit v1.2.3