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/util.go

@@ -1,65 +1,7 @@
 package parser
 
 import (
-	"bufio"
-
 	"github.com/tal-tech/go-zero/tools/goctl/api/spec"
 )
 
 var emptyType spec.Type
-
-func GetType(api *spec.ApiSpec, t string) spec.Type {
-	for _, tp := range api.Types {
-		if tp.Name == t {
-			return tp
-		}
-	}
-
-	return emptyType
-}
-
-func isLetterDigit(r rune) bool {
-	return (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || ('0' <= r && r <= '9')
-}
-
-func isSpace(r rune) bool {
-	return r == ' ' || r == '\t'
-}
-
-func isSlash(r rune) bool {
-	return r == '/'
-}
-
-func isNewline(r rune) bool {
-	return r == '\n' || r == '\r'
-}
-
-func read(r *bufio.Reader) (rune, error) {
-	ch, _, err := r.ReadRune()
-	return ch, err
-}
-
-func readLine(r *bufio.Reader) (string, error) {
-	line, _, err := r.ReadLine()
-	if err != nil {
-		return "", err
-	} else {
-		return string(line), nil
-	}
-}
-
-func skipSpaces(r *bufio.Reader) error {
-	for {
-		next, err := read(r)
-		if err != nil {
-			return err
-		}
-		if !isSpace(next) {
-			return unread(r)
-		}
-	}
-}
-
-func unread(r *bufio.Reader) error {
-	return r.UnreadRune()
-}