go正则表达式

https://github.com/cookieY/Yearning/blob/ad6c04b2904bb4cdcb64f732ce088d072751074e/src/lib/toolbox.go#L237

package soar
	import (
	"errors"
	"fmt"
	"github.com/pingcap/parser"
	"github.com/pingcap/parser/ast"
	_ "github.com/pingcap/tidb/types/parser_driver"
	"log"
	"regexp"
	"strings"
	)
	func MergeAlterTables(sql string) (string, error) {
	alterSQLs := make(map[string][]string)
	var mergedAlterStr string
	var nonSqls string
	// table/column/index name can be quoted in back ticks
	backTicks := "(`[^\\s]*`)"
	alterExp := regexp.MustCompile(`(?i)alter\s*table\s*(` + backTicks + `|([^\s]*))\s*`) // ALTER TABLE
	createIndexExp := regexp.MustCompile(`(?i)create((unique)|(fulltext)|(spatial)|(primary)|(\s*)\s*)((index)|(key))\s*`)
	renameExp := regexp.MustCompile(`(?i)rename\s*table\s*(` + backTicks + `|([^\s]*))\s*`) // RENAME TABLE
	indexNameExp := regexp.MustCompile(`(?i)(` + backTicks + `|([^\s]*))\s*`)
	indexColsExp := regexp.MustCompile(`(?i)(` + backTicks + `|([^\s]*))\s*on\s*(` + backTicks + `|([^\s]*))\s*`)
	p := parser.New()
	stmt, _, err := p.Parse(sql, "", "")
	if err != nil {
	return "", errors.New(err.Error())
	}
	for _, idx := range stmt {
	alterSQL := ""
	dbName := ""
	tableName := ""
	switch n := idx.(type) {
	case *ast.AlterTableStmt:
	sols := strings.Trim(n.Text(), ";")
	tableName = n.Table.Name.L
	dbName = n.Table.Schema.L
	if alterExp.MatchString(sols) {
	alterSQL = fmt.Sprint(alterExp.ReplaceAllString(sols, ""))
	} else if createIndexExp.MatchString(sols) {
	buf := createIndexExp.ReplaceAllString(sols, "")
	idxName := strings.TrimSpace(indexNameExp.FindString(buf))
	buf = indexColsExp.ReplaceAllString(buf, "")
	alterSQL = fmt.Sprint("ADD INDEX", " "+idxName+" ", buf)
	}
	case *ast.RenameTableStmt:
	sols := strings.Trim(n.Text(), ";")
	if alterExp.MatchString(sols) {
	alterSQL = fmt.Sprint(alterExp.ReplaceAllString(sols, ""))
	} else if renameExp.MatchString(sols) {
	alterSQL = fmt.Sprint(alterExp.ReplaceAllString(sols, ""))
	} else {
	log.Printf("rename not match: %v", n.Text())
	}
	default:
	nonSqls += n.Text() + "\n"
	}
	if alterSQL != "" && tableName != "" && tableName != "dual" {
	if dbName == "" {
	alterSQLs["`"+tableName+"`"] = append(alterSQLs["`"+tableName+"`"], alterSQL)
	} else {
	alterSQLs["`"+dbName+"`.`"+tableName+"`"] = append(alterSQLs["`"+dbName+"`.`"+tableName+"`"], alterSQL)
	}
	}
	}
	for k, v := range alterSQLs {
	mergedAlterStr += fmt.Sprintln("ALTER TABLE", k, strings.Join(v, ", "), ";")
	}
	mergedAlterStr += nonSqls
	return mergedAlterStr, nil
	}