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/import.go

@@ -0,0 +1,96 @@
+package ast
+
+import (
+	"github.com/tal-tech/go-zero/tools/goctl/api/parser/g4/gen/api"
+)
+
+type ImportExpr struct {
+	Import      Expr
+	Value       Expr
+	DocExpr     []Expr
+	CommentExpr Expr
+}
+
+func (v *ApiVisitor) VisitImportSpec(ctx *api.ImportSpecContext) interface{} {
+	var list []*ImportExpr
+	if ctx.ImportLit() != nil {
+		lits := ctx.ImportLit().Accept(v).([]*ImportExpr)
+		list = append(list, lits...)
+	}
+	if ctx.ImportBlock() != nil {
+		blocks := ctx.ImportBlock().Accept(v).([]*ImportExpr)
+		list = append(list, blocks...)
+	}
+
+	return list
+}
+
+func (v *ApiVisitor) VisitImportLit(ctx *api.ImportLitContext) interface{} {
+	importToken := v.newExprWithToken(ctx.GetImportToken())
+	valueExpr := ctx.ImportValue().Accept(v).(Expr)
+	return []*ImportExpr{
+		{
+			Import:      importToken,
+			Value:       valueExpr,
+			DocExpr:     v.getDoc(ctx),
+			CommentExpr: v.getComment(ctx),
+		},
+	}
+}
+
+func (v *ApiVisitor) VisitImportBlock(ctx *api.ImportBlockContext) interface{} {
+	importToken := v.newExprWithToken(ctx.GetImportToken())
+	values := ctx.AllImportBlockValue()
+	var list []*ImportExpr
+
+	for _, value := range values {
+		importExpr := value.Accept(v).(*ImportExpr)
+		importExpr.Import = importToken
+		list = append(list, importExpr)
+	}
+
+	return list
+}
+
+func (v *ApiVisitor) VisitImportBlockValue(ctx *api.ImportBlockValueContext) interface{} {
+	value := ctx.ImportValue().Accept(v).(Expr)
+	return &ImportExpr{
+		Value:       value,
+		DocExpr:     v.getDoc(ctx),
+		CommentExpr: v.getComment(ctx),
+	}
+}
+
+func (v *ApiVisitor) VisitImportValue(ctx *api.ImportValueContext) interface{} {
+	return v.newExprWithTerminalNode(ctx.STRING())
+}
+
+func (i *ImportExpr) Format() error {
+	// todo
+	return nil
+}
+
+func (i *ImportExpr) Equal(v interface{}) bool {
+	if v == nil {
+		return false
+	}
+
+	imp, ok := v.(*ImportExpr)
+	if !ok {
+		return false
+	}
+
+	if !EqualDoc(i, imp) {
+		return false
+	}
+
+	return i.Import.Equal(imp.Import) && i.Value.Equal(imp.Value)
+}
+
+func (i *ImportExpr) Doc() []Expr {
+	return i.DocExpr
+}
+
+func (i *ImportExpr) Comment() Expr {
+	return i.CommentExpr
+}