feature: refactor api parse to g4 (#365)

* feature: refactor api parse to g4

* new g4 parser

* add CHANGE_LOG.MD

* refactor

* fix byte bug

* refactor

* optimized

* optimized

* revert

* update readme.md

* update readme.md

* update readme.md

* update readme.md

* remove no need

* fix java gen

* add upgrade

* resolve confilits

Co-authored-by: anqiansong <anqiansong@xiaoheiban.cn>

tools/goctl/api/parser/g4/ast/kv.go

@@ -0,0 +1,79 @@
+package ast
+
+import (
+	"strings"
+
+	"github.com/tal-tech/go-zero/tools/goctl/api/parser/g4/gen/api"
+)
+
+type KvExpr struct {
+	Key         Expr
+	Value       Expr
+	DocExpr     []Expr
+	CommentExpr Expr
+}
+
+func (v *ApiVisitor) VisitKvLit(ctx *api.KvLitContext) interface{} {
+	var kvExpr KvExpr
+	kvExpr.Key = v.newExprWithToken(ctx.GetKey())
+	commentExpr := v.getComment(ctx)
+	if ctx.GetValue() != nil {
+		valueText := ctx.GetValue().GetText()
+		valueExpr := v.newExprWithToken(ctx.GetValue())
+		if strings.Contains(valueText, "//") {
+			if commentExpr == nil {
+				commentExpr = v.newExprWithToken(ctx.GetValue())
+				commentExpr.SetText("")
+			}
+
+			index := strings.Index(valueText, "//")
+			commentExpr.SetText(valueText[index:])
+			valueExpr.SetText(strings.TrimSpace(valueText[:index]))
+		} else if strings.Contains(valueText, "/*") {
+			if commentExpr == nil {
+				commentExpr = v.newExprWithToken(ctx.GetValue())
+				commentExpr.SetText("")
+			}
+
+			index := strings.Index(valueText, "/*")
+			commentExpr.SetText(valueText[index:])
+			valueExpr.SetText(strings.TrimSpace(valueText[:index]))
+		}
+
+		kvExpr.Value = valueExpr
+	}
+
+	kvExpr.DocExpr = v.getDoc(ctx)
+	kvExpr.CommentExpr = commentExpr
+	return &kvExpr
+}
+
+func (k *KvExpr) Format() error {
+	// todo
+	return nil
+}
+
+func (k *KvExpr) Equal(v interface{}) bool {
+	if v == nil {
+		return false
+	}
+
+	kv, ok := v.(*KvExpr)
+	if !ok {
+		return false
+	}
+
+	if !EqualDoc(k, kv) {
+		return false
+	}
+
+	return k.Key.Equal(kv.Key) && k.Value.Equal(kv.Value)
+}
+
+func (k *KvExpr) Doc() []Expr {
+	return k.DocExpr
+}
+
+func (k *KvExpr) Comment() Expr {
+	return k.CommentExpr
+}