Uploaded by UploadToGist for Sublime Text 2

grammar.coffee

{Parser} = require 'jison'

# Stolen from coffee-script

# Since we're going to be wrapped in a function by Jison in any case, if our
# action immediately returns a value, we can optimize by removing the function
# wrapper and just returning the value directly.
unwrap = /^function\s*\(\)\s*\{\s*return\s*([\s\S]*);\s*\}/

# Our handy DSL for Jison grammar generation, thanks to
# [Tim Caswell](http://github.com/creationix). For every rule in the grammar,
# we pass the pattern-defining string, the action to run, and extra options,
# optionally. If no action is specified, we simply pass the value of the
# previous nonterminal.
o = (patternString, action, options) ->
  patternString = patternString.replace /\s{2,}/g, ' '
  return [patternString, '$$ = $1;', options] unless action
  action = if match = unwrap.exec action then match[1] else "(#{action}())"
  action = action.replace /\bnew /g, '$&yy.'
  action = action.replace /\b(?:Block\.wrap|extend)\b/g, 'yy.$&'
  [patternString, "$$ = #{action};", options]

t = (regex, name) ->
  [regex.toString().slice(1, -1), if name then "return #{JSON.stringify(name)};" else "/* om nom nom */"]

grammar = lex: {}

grammar.lex.rules = [
  t /\s+/
  t /[0-9]+(?:\.[0-9]+)?\b/, 'NUMBER'

  t /\*/, '*'
  t /\//, '/'
  t /\+/, '+'
  t /\-/, '-'
  t /\=/, '='

  t /\(/, '('
  t /\)/, ')'

  t /\?/, '?'
  t /:/, ':'

  t /\{/, '{'
  t /\}/, '}'
  t /\[/, '['
  t /\]/, ']'

  t /if/, 'IF'
  t /else/, 'ELSE'
  t /elseif/, 'ELSEIF'
  t /while/, 'WHILE'
  t /[a-z][A-Za-z0-9_]+/, 'FUNC'
  t /[A-Z][A-Za-z0-9_]+/, 'VAR'

  t /@/, '@'
  t /\n/, 'EOL'
]

grammar.bnf =
   Root: [
     o 'DirectiveList StatementList'
   ]
   DirectiveList: [
    o 'Directive DirectiveList'
    o 'Directive'
    o ''
   ]
   Directive: [
    o '@ VAR EOL'
   ]
   StatementList: [
    o 'Statement StatementList'
    o 'Statement'
    o ''
   ]


console.log JSON.stringify grammar