fix empty

Author: syyongx

php.go

@@ -1629,6 +1629,9 @@ func Glob(pattern string) ([]string, error) {
 
 // Empty empty()
 func Empty(val interface{}) bool {
+	if val == nil {
+		return true
+	}
 	v := reflect.ValueOf(val)
 	switch v.Kind() {
 	case reflect.String, reflect.Array:

php_test.go

@@ -308,6 +308,16 @@ func TestVariable(t *testing.T) {
 
 	tIsNumeric = IsNumeric("123456")
 	equal(t, true, tIsNumeric)
+
+	equal(t, true, Empty(nil))
+	equal(t, true, Empty(false))
+	equal(t, true, Empty(0))
+	equal(t, true, Empty(""))
+	equal(t, true, Empty(0.0))
+	equal(t, true, Empty([]int{}))
+	equal(t, true, Empty([0]int{}))
+	equal(t, false, Empty([1]int{}))
+	equal(t, true, Empty(map[int]int{}))
 }
 
 func TestProgramExecution(t *testing.T) {