Go - How to create a parser

Question

I want to build a parser but have some problems understanding how to do this.

Sample string I would like to parse

{key1 = value1 | key2 = {key3 = val         


        

Answer 1

That particular format is very similar to json. You could use the following code to leverage that similarity:

    var txt = `{key1 = "\"value1\"\n" | key2 = { key3 = 10 } | key4 = {key5 = { key6 = value6}}}`
    var s scanner.Scanner
    s.Init(strings.NewReader(txt))
    var b []byte

loop:
    for {
        switch tok := s.Scan(); tok {
        case scanner.EOF:
            break loop
        case '|':
            b = append(b, ',')
        case '=':
            b = append(b, ':')
        case scanner.Ident:
            b = append(b, strconv.Quote(s.TokenText())...)
        default:
            b = append(b, s.TokenText()...)
        }
    }

    var m map[string]interface{}
    err := json.Unmarshal(b, &m)
    if err != nil {
        // handle error
    }

    fmt.Printf("%#v\n",m)