danielkalen/smart-extend

module.exports = ()->
    name: 'macros'
    transform: (content, id)->
        return null if not id.endsWith('.coffee')
        
        result = 
        require('falafel') content, sourceType:'module', (node)-> if node.type is 'Identifier'
            switch node.name
                when 'EXPAND_ARGUMENTS'
                    targetName = 'args'
                    slicePos = 0
                    
                    if node.parent.type is 'CallExpression'
                        targetName = node.parent.arguments[0].name
                        if node.parent.arguments[1]
                            slicePos = node.parent.arguments[1].value or 0

                    node.parent.update("
                        var $_len = arguments.length,
                            $_i = #{slicePos-1},
                            #{targetName} = new Array($_len);

                        while (++$_i < $_len)
                            #{targetName}[$_i] = arguments[$_i]
                    ")

        return result.toString()

# module.exports = (file, options, file_, content)->
#     return content if not file.endsWith('.js')