repl.coffee

Jump To … +

browser.coffee cake.coffee coffee-script.coffee command.coffee grammar.coffee helpers.coffee index.coffee lexer.coffee nodes.coffee optparse.coffee repl.coffee rewriter.coffee scope.litcoffee sourcemap.coffee

repl.coffee

vm = require 'vm'
nodeREPL = require 'repl'
CoffeeScript = require './coffee-script'
{merge, prettyErrorMessage} = require './helpers'

replDefaults =
  prompt: 'coffee> ',
  eval: (input, context, filename, cb) ->

XXX: multiline hack.

    input = input.replace /\uFF00/g, '\n'

¶

Node's REPL sends the input ending with a newline and then wrapped in parens. Unwrap all that.
```
    input = input.replace /^$([\s\S]*)\n$$/m, '$1'
```

Require AST nodes to do some AST manipulation.

    {Block, Assign, Value, Literal} = require './nodes'

¶

TODO: fix #1829: pass in-scope vars and avoid accidentally shadowing them by omitting those declarations
```
    try
```
¶

Generate the AST of the clean input.
```
      ast = CoffeeScript.nodes input
```

Add assignment to _ variable to force the input to be an expression.

      ast = new Block [
        new Assign (new Value new Literal '_'), ast, '='
      ]
      js = ast.compile bare: yes
    catch err
      console.log prettyErrorMessage err, filename, input, yes
    cb null, vm.runInContext(js, context, filename)

addMultilineHandler = (repl) ->
  {rli, inputStream, outputStream} = repl

  multiline =
    enabled: off
    initialPrompt: repl.prompt.replace(/^[^> ]*/, (x) -> x.replace /./g, '-')
    prompt: repl.prompt.replace(/^[^> ]*>?/, (x) -> x.replace /./g, '.')
    buffer: ''

Proxy node's line listener

  nodeLineListener = rli.listeners('line')[0]
  rli.removeListener 'line', nodeLineListener
  rli.on 'line', (cmd) ->
    if multiline.enabled
      multiline.buffer += "#{cmd}\n"
      rli.setPrompt multiline.prompt
      rli.prompt true
    else
      nodeLineListener cmd
    return

Handle Ctrl-v

  inputStream.on 'keypress', (char, key) ->
    return unless key and key.ctrl and not key.meta and not key.shift and key.name is 'v'
    if multiline.enabled

allow arbitrarily switching between modes any time before multiple lines are entered

      unless multiline.buffer.match /\n/
        multiline.enabled = not multiline.enabled
        rli.setPrompt repl.prompt
        rli.prompt true
        return

no-op unless the current line is empty

      return if rli.line? and not rli.line.match /^\s*$/

eval, print, loop

      multiline.enabled = not multiline.enabled
      rli.line = ''
      rli.cursor = 0
      rli.output.cursorTo 0
      rli.output.clearLine 1

XXX: multiline hack

      multiline.buffer = multiline.buffer.replace /\n/g, '\uFF00'
      rli.emit 'line', multiline.buffer
      multiline.buffer = ''
    else
      multiline.enabled = not multiline.enabled
      rli.setPrompt multiline.initialPrompt
      rli.prompt true
    return

module.exports =
  start: (opts = {}) ->
    opts = merge replDefaults, opts
    repl = nodeREPL.start opts
    repl.on 'exit', -> repl.outputStream.write '\n'
    addMultilineHandler repl
    repl