jade
Version:
Jade template engine
144 lines (120 loc) • 2.6 kB
JavaScript
/*!
* Stylus - Expression
* Copyright(c) 2010 LearnBoost <dev@learnboost.com>
* MIT Licensed
*/
/**
* Module dependencies.
*/
var Node = require('./node')
, nodes = require('../nodes')
, utils = require('../utils');
/**
* Initialize a new `Expression`.
*
* @param {Boolean} isList
* @api public
*/
var Expression = module.exports = function Expression(isList){
Node.call(this);
this.nodes = [];
this.isList = isList;
};
/**
* Check if the variable has a value.
*
* @return {Boolean}
* @api public
*/
Expression.prototype.__defineGetter__('isEmpty', function(){
return !this.nodes.length;
});
/**
* Return the first node in this expression.
*
* @return {Node}
* @api public
*/
Expression.prototype.__defineGetter__('first', function(){
return this.nodes[0]
? this.nodes[0].first
: nodes.null;
});
/**
* Hash all the nodes in order.
*
* @return {String}
* @api public
*/
Expression.prototype.__defineGetter__('hash', function(){
return this.nodes.map(function(node){
return node.hash;
}).join('::');
});
/**
* Inherit from `Node.prototype`.
*/
Expression.prototype.__proto__ = Node.prototype;
/**
* Return a clone of this node.
*
* @return {Node}
* @api public
*/
Expression.prototype.clone = function(){
var clone = new Expression(this.isList);
clone.preserve = this.preserve;
clone.lineno = this.lineno;
for (var i = 0; i < this.nodes.length; ++i) {
clone.push(this.nodes[i].clone());
}
return clone;
};
/**
* Push the given `node`.
*
* @param {Node} node
* @api public
*/
Expression.prototype.push = function(node){
this.nodes.push(node);
};
/**
* Operate on `right` with the given `op`.
*
* @param {String} op
* @param {Node} right
* @return {Node}
* @api public
*/
Expression.prototype.operate = function(op, right){
switch (op) {
case '[]':
var expr = new nodes.Expression
, vals = utils.unwrap(this).nodes
, range = utils.unwrap(right).nodes;
range.forEach(function(unit){
if ('unit' == unit.nodeName) {
var node = vals[unit.val];
if (node) expr.push(node);
}
});
return expr.isEmpty
? nodes.null
: expr;
default:
return Node.prototype.operate.call(this, op, right);
}
};
/**
* Return "<a> <b> <c>" or "<a>, <b>, <c>" if
* the expression represents a list.
*
* @return {String}
* @api public
*/
Expression.prototype.toString = function(){
return '(' + this.nodes.map(function(node){
return node.toString();
}).join(this.isList ? ', ' : ' ') + ')';
};