sibliantjs 解释 S 表达式

token.coffee

# code from https://github.com/jbr/sibilant/blob/a5d43850eeb86d7859b04016e955a02690246f20/speech_therapist.js

ll = console.log
plat = (arr) ->
  str = ''
  arr = arr.map (x) ->
    if typeof x is 'object'
      return plat x
    else return x
  return "[#{arr.join ' '}]"

tokenize = (string) ->

  tokens = []
  parseStack = [tokens]
  lp = (msg) ->
    ll msg, '::', plat parseStack

  acceptToken = (t) ->
    lp 'acc b:'
    ll 'acc <-', t
    parseStack[0].push t
    lp 'acc e:'

  increaseNesting = ->
    lp 'inc b:'
    ll 'inc <-', '('
    newArr = []
    acceptToken newArr
    parseStack.unshift newArr
    lp 'inc e:'

  decreaseNesting = ->
    lp 'dec b:'
    ll 'dec <-', ')'
    parseStack.shift()
    if parseStack.length is 0
      throw new Error 'unbalanced parens:\n' +
        sys.inspect parseStack
    lp 'dec e:'

  handleToken = (token) ->
    if token is '(' then increaseNesting()
    else if token is ')' then decreaseNesting()
    else if token.match /^-?[0-9.]+$/
      acceptToken (parseFloat token)
    else acceptToken token

  tmp = string.replace(/([^\\])\n/, '$1 ')
    .replace(/\s+\\\n/, '\\n')
  console.log tmp
  tmp = tmp.match(///
        (;.*)
      | ("([^"]
      | (\\"))*?[^\\]")
      | [&']?[.a-z-]+
      | [><=!\+\/\*-]+
      | -?[0-9.]+
      | ([`']?\()
      | \)
      ///g)
  console.log tmp
  tmp.forEach handleToken

  return tokens

str = '(+ (* (- 4 1) 5) 6)'
console.log (tokenize str)

token.coffee.log

$ coffee token.coffee 
(+ (* (- 4 1) 5) 6)
[ '(', '+', '(', '*', '(', '-', '4', '1', ')', '5', ')', '6', ')' ]
inc b: :: [[]]
inc <- (
acc b: :: [[]]
acc <- []
acc e: :: [[[]]]
inc e: :: [[] [[]]]
acc b: :: [[] [[]]]
acc <- +
acc e: :: [[+] [[+]]]
inc b: :: [[+] [[+]]]
inc <- (
acc b: :: [[+] [[+]]]
acc <- []
acc e: :: [[+ []] [[+ []]]]
inc e: :: [[] [+ []] [[+ []]]]
acc b: :: [[] [+ []] [[+ []]]]
acc <- *
acc e: :: [[*] [+ [*]] [[+ [*]]]]
inc b: :: [[*] [+ [*]] [[+ [*]]]]
inc <- (
acc b: :: [[*] [+ [*]] [[+ [*]]]]
acc <- []
acc e: :: [[* []] [+ [* []]] [[+ [* []]]]]
inc e: :: [[] [* []] [+ [* []]] [[+ [* []]]]]
acc b: :: [[] [* []] [+ [* []]] [[+ [* []]]]]
acc <- -
acc e: :: [[-] [* [-]] [+ [* [-]]] [[+ [* [-]]]]]
acc b: :: [[-] [* [-]] [+ [* [-]]] [[+ [* [-]]]]]
acc <- 4
acc e: :: [[- 4] [* [- 4]] [+ [* [- 4]]] [[+ [* [- 4]]]]]
acc b: :: [[- 4] [* [- 4]] [+ [* [- 4]]] [[+ [* [- 4]]]]]
acc <- 1
acc e: :: [[- 4 1] [* [- 4 1]] [+ [* [- 4 1]]] [[+ [* [- 4 1]]]]]
dec b: :: [[- 4 1] [* [- 4 1]] [+ [* [- 4 1]]] [[+ [* [- 4 1]]]]]
dec <- )
dec e: :: [[* [- 4 1]] [+ [* [- 4 1]]] [[+ [* [- 4 1]]]]]
acc b: :: [[* [- 4 1]] [+ [* [- 4 1]]] [[+ [* [- 4 1]]]]]
acc <- 5
acc e: :: [[* [- 4 1] 5] [+ [* [- 4 1] 5]] [[+ [* [- 4 1] 5]]]]
dec b: :: [[* [- 4 1] 5] [+ [* [- 4 1] 5]] [[+ [* [- 4 1] 5]]]]
dec <- )
dec e: :: [[+ [* [- 4 1] 5]] [[+ [* [- 4 1] 5]]]]
acc b: :: [[+ [* [- 4 1] 5]] [[+ [* [- 4 1] 5]]]]
acc <- 6
acc e: :: [[+ [* [- 4 1] 5] 6] [[+ [* [- 4 1] 5] 6]]]
dec b: :: [[+ [* [- 4 1] 5] 6] [[+ [* [- 4 1] 5] 6]]]
dec <- )
dec e: :: [[[+ [* [- 4 1] 5] 6]]]
[ [ '+', [ '*', [Object], 5 ], 6 ] ]