From 7a661358ad5fd668cb35df7a5886308a2fc37602 Mon Sep 17 00:00:00 2001
From: Brian Anderson <andersrb@gmail.com>
Date: Tue, 15 Mar 2011 18:45:56 -0400
Subject: [PATCH 1/3] Remove usages of case(_) { fail; } since the compiler
 does this automatically

---
 src/comp/middle/trans.rs  | 3 ---
 src/comp/middle/typeck.rs | 6 ------
 src/lib/deque.rs          | 1 -
 src/lib/map.rs            | 1 -
 4 files changed, 11 deletions(-)

diff --git a/src/comp/middle/trans.rs b/src/comp/middle/trans.rs
index d4cd399228951..e81d5a091e48e 100644
--- a/src/comp/middle/trans.rs
+++ b/src/comp/middle/trans.rs
@@ -1753,7 +1753,6 @@ fn variant_types(@crate_ctxt cx, &ast.variant v) -> vec[@ty.t] {
             }
         }
         case (ty.ty_tag(_, _)) { /* nothing */ }
-        case (_) { fail; }
     }
     ret tys;
 }
@@ -1966,7 +1965,6 @@ fn iter_structural_ty_full(@block_ctxt cx,
                                 j += 1;
                             }
                         }
-                        case (_) { fail; }
                     }
 
                     variant_cx.build.Br(next_cx.llbb);
@@ -2133,7 +2131,6 @@ fn iter_sequence(@block_ctxt cx,
             auto et = plain_ty(ty.ty_machine(common.ty_u8));
             ret iter_sequence_body(cx, v, et, f, true);
         }
-        case (_) { fail; }
     }
     cx.fcx.ccx.sess.bug("bad type in trans.iter_sequence");
     fail;
diff --git a/src/comp/middle/typeck.rs b/src/comp/middle/typeck.rs
index c849483e8addd..75d6a8fff6101 100644
--- a/src/comp/middle/typeck.rs
+++ b/src/comp/middle/typeck.rs
@@ -1861,9 +1861,6 @@ fn check_expr(&@fn_ctxt fcx, @ast.expr expr) -> @ast.expr {
                 case (ty.ty_chan(?it)) {
                     item_t = it;
                 }
-                case (_) {
-                    fail;
-                }
             }
             auto rhs_1 = demand_expr(fcx, item_t, rhs_0);
 
@@ -1884,9 +1881,6 @@ fn check_expr(&@fn_ctxt fcx, @ast.expr expr) -> @ast.expr {
                 case (ty.ty_port(?it)) {
                     item_t = it;
                 }
-                case (_) {
-                    fail;
-                }
             }
             auto lhs_1 = demand_expr(fcx, item_t, lhs_0);
 
diff --git a/src/lib/deque.rs b/src/lib/deque.rs
index 776f82e99fe8f..704e674930076 100644
--- a/src/lib/deque.rs
+++ b/src/lib/deque.rs
@@ -47,7 +47,6 @@ fn create[T]() -> t[T] {
     fn get[T](vec[cell[T]] elts, uint i) -> T {
         alt (elts.(i)) {
             case (option.some[T](?t)) { ret t; }
-            case (_) { fail; }
         }
         fail;   // FIXME: remove me when exhaustiveness checking works
     }
diff --git a/src/lib/map.rs b/src/lib/map.rs
index f22faaca7194a..d8e2431408640 100644
--- a/src/lib/map.rs
+++ b/src/lib/map.rs
@@ -176,7 +176,6 @@ fn mk_hashmap[K, V](&hashfn[K] hasher, &eqfn[K] eqer) -> hashmap[K, V] {
             fn get(&K key) -> V {
                 alt (find_common[K, V](hasher, eqer, bkts, nbkts, key)) {
                     case (option.some[V](?val)) { ret val; }
-                    case (_) { fail; }
                 }
                 fail;   // FIXME: remove me when exhaustiveness checking works
             }

From 1cae322aa236761eaa4d26ed98a56eca261eebfd Mon Sep 17 00:00:00 2001
From: Brian Anderson <andersrb@gmail.com>
Date: Wed, 16 Mar 2011 22:28:00 -0400
Subject: [PATCH 2/3] Update docs for if statements

---
 doc/rust.texi | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/doc/rust.texi b/doc/rust.texi
index 48a639ddcd17f..4b92fa94d3ec0 100644
--- a/doc/rust.texi
+++ b/doc/rust.texi
@@ -3310,11 +3310,14 @@ for each (str s in _str.split(txt, "\n")) @{
 
 An @code{if} statement is a conditional branch in program control. The form of
 an @code{if} statement is a parenthesized condition expression, followed by a
-consequent block, and an optional trailing @code{else} block. The condition
-expression must have type @code{bool}. If the condition expression evaluates
-to @code{true}, the consequent block is executed and any @code{else} block is
-skipped. If the condition expression evaluates to @code{false}, the consequent
-block is skipped and any @code{else} block is executed.
+consequent block, any number of @code{else if} conditions and blocks, and an
+optional trailing @code{else} block. The condition expressions must have type
+@code{bool}. If a condition expression evaluates to @code{true}, the
+consequent block is executed and any subsequent @code{else if} or @code{else}
+block is skipped. If a condition expression evaluates to @code{false}, the
+consequent block is skipped and any subsequent @code{else if} condition is
+evaluated. If all @code{if} and @code{else if} conditions evaluate to @code{false}
+then any @code{else} block is executed.
 
 @node       Ref.Stmt.Alt
 @subsection Ref.Stmt.Alt

From 87323573772619a99b07b4610639c6ec9c69c670 Mon Sep 17 00:00:00 2001
From: Brian Anderson <andersrb@gmail.com>
Date: Mon, 14 Mar 2011 19:57:12 -0400
Subject: [PATCH 3/3] Add some nesting to the else-if test case

---
 src/test/run-pass/else-if.rs | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/test/run-pass/else-if.rs b/src/test/run-pass/else-if.rs
index 9e3eac149fd80..d9e5b8690250f 100644
--- a/src/test/run-pass/else-if.rs
+++ b/src/test/run-pass/else-if.rs
@@ -16,4 +16,27 @@ fn main() {
     check(true);
   }
 
-}
\ No newline at end of file
+  if (1 == 2) {
+    check(false);
+  } else if (2 == 2) {
+    if (1 == 1) {
+      check(true);
+    } else {
+      if (2 == 1) {
+        check(false);
+      } else {
+        check(false);
+      }
+    }
+  }
+
+  if (1 == 2) {
+    check(false);
+  } else {
+    if (1 == 2) {
+      check(false);
+    } else {
+      check(true);
+    }
+  }
+}