less.js/lib/less/tree/unit.js

module.exports = function(tree, unitConversions) {

var Unit = function (numerator, denominator, backupUnit) {
    this.numerator = numerator ? numerator.slice(0).sort() : [];
    this.denominator = denominator ? denominator.slice(0).sort() : [];
    this.backupUnit = backupUnit;
};

Unit.prototype = {
    type: "Unit",
    clone: function () {
        return new Unit(this.numerator.slice(0), this.denominator.slice(0), this.backupUnit);
    },
    genCSS: function (env, output) {
        if (this.numerator.length >= 1) {
            output.add(this.numerator[0]);
        } else
        if (this.denominator.length >= 1) {
            output.add(this.denominator[0]);
        } else
        if ((!env || !env.strictUnits) && this.backupUnit) {
            output.add(this.backupUnit);
        }
    },
    toCSS: tree.toCSS,

    toString: function () {
        var i, returnStr = this.numerator.join("*");
        for (i = 0; i < this.denominator.length; i++) {
            returnStr += "/" + this.denominator[i];
        }
        return returnStr;
    },

    compare: function (other) {
        return this.is(other.toString()) ? 0 : -1;
    },

    is: function (unitString) {
        return this.toString() === unitString;
    },

    isLength: function () {
        return Boolean(this.toCSS().match(/px|em|%|in|cm|mm|pc|pt|ex/));
    },

    isEmpty: function () {
        return this.numerator.length === 0 && this.denominator.length === 0;
    },

    isSingular: function() {
        return this.numerator.length <= 1 && this.denominator.length === 0;
    },

    map: function(callback) {
        var i;

        for (i = 0; i < this.numerator.length; i++) {
            this.numerator[i] = callback(this.numerator[i], false);
        }

        for (i = 0; i < this.denominator.length; i++) {
            this.denominator[i] = callback(this.denominator[i], true);
        }
    },

    usedUnits: function() {
        var group, result = {}, mapUnit;

        mapUnit = function (atomicUnit) {
            /*jshint loopfunc:true */
            if (group.hasOwnProperty(atomicUnit) && !result[groupName]) {
                result[groupName] = atomicUnit;
            }

            return atomicUnit;
        };

        for (var groupName in unitConversions) {
            if (unitConversions.hasOwnProperty(groupName)) {
                group = unitConversions[groupName];

                this.map(mapUnit);
            }
        }

        return result;
    },

    cancel: function () {
        var counter = {}, atomicUnit, i, backup;

        for (i = 0; i < this.numerator.length; i++) {
            atomicUnit = this.numerator[i];
            if (!backup) {
                backup = atomicUnit;
            }
            counter[atomicUnit] = (counter[atomicUnit] || 0) + 1;
        }

        for (i = 0; i < this.denominator.length; i++) {
            atomicUnit = this.denominator[i];
            if (!backup) {
                backup = atomicUnit;
            }
            counter[atomicUnit] = (counter[atomicUnit] || 0) - 1;
        }

        this.numerator = [];
        this.denominator = [];

        for (atomicUnit in counter) {
            if (counter.hasOwnProperty(atomicUnit)) {
                var count = counter[atomicUnit];

                if (count > 0) {
                    for (i = 0; i < count; i++) {
                        this.numerator.push(atomicUnit);
                    }
                } else if (count < 0) {
                    for (i = 0; i < -count; i++) {
                        this.denominator.push(atomicUnit);
                    }
                }
            }
        }

        if (this.numerator.length === 0 && this.denominator.length === 0 && backup) {
            this.backupUnit = backup;
        }

        this.numerator.sort();
        this.denominator.sort();
    }
};
return Unit;
};