optimize Pattern.WeakEqual

pattern.go

@@ -53,16 +53,16 @@ func (p *Pattern) WeakEqual(other *Pattern) bool {
 	if len(p.words) != len(other.words) {
 		return false
 	}
-	var matches int
-	for i, op := range other.words {
-		if p.words[i] == op {
-			matches++
+	var diffs int
+	for i, ow := range other.words {
+		if p.words[i] != ow {
+			diffs++
+			if diffs > 1 {
+				return false
+			}
 		}
 	}
-	if matches >= len(p.words)-1 {
-		return true
-	}
-	return false
+	return true
 }
 
 func NewPattern(input string) *Pattern {

pattern_test.go

@@ -82,6 +82,14 @@ func TestPatternWeakEqual(t *testing.T) {
 	assert.False(t, NewPattern("foo bar baz").WeakEqual(NewPattern("baz bar foo")))
 }
 
+func BenchmarkPatternWeakEqual(b *testing.B) {
+	p1 := NewPattern("foo one two bar buz")
+	p2 := NewPattern("foo three four bar buz")
+	for n := 0; n < b.N; n++ {
+		p1.WeakEqual(p2)
+	}
+}
+
 func TestPatternRemoveQuotedAndBrackets(t *testing.T) {
 	assert.Equal(t, "foo  bar", removeQuotedAndBrackets(`foo 'squoted' bar`))
 	assert.Equal(t, "foo  bar", removeQuotedAndBrackets(`foo 'squoted \'baz\'' bar`))