runtime(go): minimum requirement go1.18

golang.org/x/exp,
which requires newer go version,
is too heavy for previous implementation

Signed-off-by: Kyle Xiao <xiaost7@gmail.com>

runtime/Go/antlr/v4/go.mod

@@ -1,5 +1,3 @@
 module github.com/antlr4-go/antlr/v4
 
-go 1.20
-
-require golang.org/x/exp v0.0.0-20230515195305-f3d0a9c9a5cc
+go 1.18

runtime/Go/antlr/v4/go.sum

@@ -1,4 +0,0 @@
-golang.org/x/exp v0.0.0-20220722155223-a9213eeb770e h1:+WEEuIdZHnUeJJmEUjyYC2gfUMj69yZXw17EnHg/otA=
-golang.org/x/exp v0.0.0-20220722155223-a9213eeb770e/go.mod h1:Kr81I6Kryrl9sr8s2FK3vxD90NdsKWRuOIl2O4CvYbA=
-golang.org/x/exp v0.0.0-20230515195305-f3d0a9c9a5cc h1:mCRnTeVUjcrhlRmO0VK8a6k6Rrf6TF9htwo2pJVSjIU=
-golang.org/x/exp v0.0.0-20230515195305-f3d0a9c9a5cc/go.mod h1:V1LtkGg67GoY2N1AnLN78QLrzxkLyJw7RJb1gzOOz9w=

runtime/Go/antlr/v4/lexer_action_executor.go

@@ -4,8 +4,6 @@
 
 package antlr
 
-import "golang.org/x/exp/slices"
-
 // Represents an executor for a sequence of lexer actions which traversed during
 // the Matching operation of a lexer rule (token).
 //
@@ -167,7 +165,10 @@ func (l *LexerActionExecutor) Equals(other interface{}) bool {
 	if len(l.lexerActions) != len(othert.lexerActions) {
 		return false
 	}
-	return slices.EqualFunc(l.lexerActions, othert.lexerActions, func(i, j LexerAction) bool {
-		return i.Equals(j)
-	})
+	for i, v := range l.lexerActions {
+		if !v.Equals(othert.lexerActions[i]) {
+			return false
+		}
+	}
+	return true
 }