package main

import (
    "fmt"

    "github.com/ghettovoice/abnf"
)

var op = abnf.Concat(
    `"a" "b" *"cd"`,
    abnf.Literal(`"a"`, []byte("a")),
    abnf.Literal(`"b"`, []byte("b")),
    abnf.Repeat0Inf(`*"cd"`, abnf.Literal(`"cd"`, []byte("cd"))),
)

func main() {
    ns := abnf.NewNodes()
    defer ns.Free()

    if err := op([]byte("ab"), 0, &ns); err != nil {
        panic(err)
    }
    fmt.Println(ns.Best())

    ns.Clear()
    if err := op([]byte("abcd"), 0, &ns); err != nil {
        panic(err)
    }
    fmt.Println(ns.Best())

    ns.Clear()
    if err := op([]byte("abcdcd"), 0, &ns); err != nil {
        panic(err)
    }
    fmt.Println(ns.Best())

    // Output:
    // ab
    // abcd
    // abcdcd
}