less.js/lib/less/tree/variable.js

var Node = require('./node'),
    Call = require('./call');

var Variable = function (name, index, currentFileInfo) {
    this.name = name;
    this._index = index;
    this._fileInfo = currentFileInfo;
};
Variable.prototype = new Node();
Variable.prototype.type = 'Variable';
Variable.prototype.eval = function (context) {
    var variable, name = this.name;

    if (name.indexOf('@@') === 0) {
        name = '@' + new Variable(name.slice(1), this.getIndex(), this.fileInfo()).eval(context).value;
    }

    if (this.evaluating) {
        throw { type: 'Name',
            message: 'Recursive variable definition for ' + name,
            filename: this.fileInfo().filename,
            index: this.getIndex() };
    }

    this.evaluating = true;

    variable = this.find(context.frames, function (frame) {
        var v = frame.variable(name);
        if (v) {
            if (v.important) {
                var importantScope = context.importantScope[context.importantScope.length - 1];
                importantScope.important = v.important;
            }
            // If in calc, wrap vars in a function call to cascade evaluate args first
            if (context.inCalc) {
                return (new Call('_SELF', [v.value])).eval(context);
            }
            else {
                return v.value.eval(context);
            }
        }
    });
    if (variable) {
        this.evaluating = false;
        return variable;
    } else {
        throw { type: 'Name',
            message: 'variable ' + name + ' is undefined',
            filename: this.fileInfo().filename,
            index: this.getIndex() };
    }
};
Variable.prototype.find = function (obj, fun) {
    for (var i = 0, r; i < obj.length; i++) {
        r = fun.call(obj, obj[i]);
        if (r) { return r; }
    }
    return null;
};
module.exports = Variable;