question: where is wrong?

[puccoonhuang]

I try to code a demo of participle usage
but got a err msg, "parse error:5:9: invalid input text "(\n\tgithub.com/al..."", where is wrong?
here is my code.

package main

import (
"fmt"

"github.com/alecthomas/participle/v2"
"github.com/alecthomas/participle/v2/lexer"

)

type GoModFile struct {
Module string "module" @String
Statements []Statement @@*
}

type Statement struct {
GoVersion string "go" @Version
Requirements []Dependency | ("require (" @@* ")") | ("require" @@)
Replacements []Dependency | ("replace (" @@* ")") | ("replace" @@)
Excludes []Dependency | ("exclude (" @@* ")") | ("exclude" @@)
}

type Dependency struct {
ModuleName string @String
Version string (@Version | @"latest")
Comment string (@Comment |"")
}

type Replacement struct {
FromModule string @String "=>"
ToModule Dependency @@
}

var (
modContent = `
module useparticiple
go 1.16

require (
github.com/alecthomas/participle v0.7.1 # test
github.com/alecthomas/participle v0.7.1 # test
)
gomodLexer = lexer.Must(lexer.NewSimple([]lexer.Rule{ {"Version",[v]?\d+[.]+\d+[.]?\d+, nil}, {"String", [a-zA-Z0-9_+.@-/]+, nil}, {"Comment", # [^\n]*, nil}, {"whitespace", \s+`, nil}, //special
}))

p = participle.MustBuild(&GoModFile{},
	participle.Lexer(gomodLexer),
)

)

func main() {

ast := &GoModFile{}
err := p.ParseString("", modContent, ast)

if err != nil {
	fmt.Printf("parse error:%v\n", err)
	return
}

fmt.Printf("ast:%v\n", ast)
fmt.Printf("module name:%s\n", ast.Module)
fmt.Printf("statement:\n")
for _, ele := range ast.Statements {
	fmt.Printf("\tgo version:%s\n", ele.GoVersion)
	fmt.Printf("\trequires:\n")
	for _, eleReq := range ele.Requirements {
		fmt.Printf("\t\trequire:%v\n", eleReq)
	}
	fmt.Printf("\treplaces:\n")
	for _, eleRep := range ele.Replacements {
		fmt.Printf("\t\treplace:%v\n", eleRep)
	}
	fmt.Printf("\tExcludes:\n")
	for _, eleExc := range ele.Excludes {
		fmt.Printf("\t\tExclude:%v\n", eleExc)
	}
}

}