simplify various code using new map index rule

R=r
CC=golang-dev
http://codereview.appspot.com/833044

4 files changed, 4 insertions, 7 deletions

diff --git a/src/pkg/exp/eval/expr.go b/src/pkg/exp/eval/expr.go
index e630578bd..15520830f 100644
--- a/src/pkg/exp/eval/expr.go
+++ b/src/pkg/exp/eval/expr.go
@@ -845,7 +845,7 @@ func (a *exprInfo) compileSelectorExpr(v *expr, name string) *expr {
 		}
 
 		// Don't check the same type twice and avoid loops
-		if _, ok := visited[t]; ok {
+		if visited[t] {
 			return nil
 		}
 		visited[t] = true
diff --git a/src/pkg/exp/eval/type.go b/src/pkg/exp/eval/type.go
index fbb428679..8a0a2cf2f 100644
--- a/src/pkg/exp/eval/type.go
+++ b/src/pkg/exp/eval/type.go
@@ -119,7 +119,7 @@ nextEnt:
 
 func (m typeArrayMap) Put(key []Type, v interface{}) interface{} {
 	hash := hashTypeArray(key)
-	ent, _ := m[hash]
+	ent := m[hash]
 
 	new := &typeArrayMapEntry{key, v, ent}
 	m[hash] = new
diff --git a/src/pkg/exp/eval/value.go b/src/pkg/exp/eval/value.go
index 1558d11dd..153349c43 100644
--- a/src/pkg/exp/eval/value.go
+++ b/src/pkg/exp/eval/value.go
@@ -539,10 +539,7 @@ type evalMap map[interface{}]Value
 func (m evalMap) Len(t *Thread) int64 { return int64(len(m)) }
 
 func (m evalMap) Elem(t *Thread, key interface{}) Value {
-	if v, ok := m[key]; ok {
-		return v
-	}
-	return nil
+	return m[key]
 }
 
 func (m evalMap) SetElem(t *Thread, key interface{}, val Value) {
diff --git a/src/pkg/exp/ogle/rtype.go b/src/pkg/exp/ogle/rtype.go
index b20acbad5..ce4fdb663 100644
--- a/src/pkg/exp/ogle/rtype.go
+++ b/src/pkg/exp/ogle/rtype.go
@@ -38,7 +38,7 @@ func newManualType(t eval.Type, arch Arch) *remoteType {
 	}
 
 	// Get the type map for this architecture
-	typeMap, _ := manualTypes[arch]
+	typeMap := manualTypes[arch]
 	if typeMap == nil {
 		typeMap = make(map[eval.Type]*remoteType)
 		manualTypes[arch] = typeMap