gistfile1.ls

{id} = require("prelude-ls")

patterns =
    * [/^\(/, \lparen]
    * [/^\)/, \rparen]
    * [/^\;/, \semicolon]
    * [/^\=/, \eq]

    * [/^".*?"/, \string, (s) -> s.substr(1, s.length - 2)]

    * [/^proc\b/, \proc]

    * [/^[a-zA-Z][a-zA-Z_]+/, \identifier, id]

    * [/^$/, \eof]

whitespace = /^[ \n]+/

lex_ = (code) ->
    result = []
    while code != ""
        code .= replace(whitespace, "")
        ok = false
        for [regex, type, value] in patterns
            match_ = regex.exec(code)
            continue unless match_
            code .= substr(match_[0].length)
            result.push do
                type: type
                value: value && value(match_[0])
            ok = true
            break
        if !ok
            console.log result
            throw Error("unknown token")
    result

insert-semicolons = (tokens) -> tokens

lex = lex_ >> insert-semicolons

module.exports = lex