node-less/lib/expression.js

Less Compiler For Node

(function (module) {

    var Comment = require('./comment.js'),
        Paren = require('./paren.js');

    var Expression = function (value) {
        this.value = value;
    };

    Expression.prototype = {
        type: "Expression",
        accept: function (visitor) {
            this.value = visitor.visit(this.value);
        },
        eval: function (env) {
            var returnValue,
                inParenthesis = this.parens && !this.parensInOp,
                doubleParen = false;
            if (inParenthesis) {
                env.inParenthesis();
            }
            if (this.value.length > 1) {
                returnValue = new Expression(this.value.map(function (e) {
                    return e.eval(env);
                }));
            } else if (this.value.length === 1) {
                if (this.value[0].parens && !this.value[0].parensInOp) {
                    doubleParen = true;
                }
                returnValue = this.value[0].eval(env);
            } else {
                returnValue = this;
            }
            if (inParenthesis) {
                env.outOfParenthesis();
            }
            if (this.parens && this.parensInOp && !(env.isMathOn()) && !doubleParen) {
                returnValue = new Paren(returnValue);
            }
            return returnValue;
        },
        toCSS: function (env) {
            return this.value.map(function (e) {
                return e.toCSS ? e.toCSS(env) : '';
            }).join(' ');
        },
        throwAwayComments: function () {
            this.value = this.value.filter(function(v) {
                return !(v instanceof Comment);
            });
        }
    };

    module.exports = Expression;

})(module);