codenothing/CSSTree

function Position( start, _parent ) {
    var self = this;

    if ( ! ( self instanceof Position ) ) {
        return new Position( start, _parent );
    }

    if ( _parent && _parent instanceof Position ) {
        self._parent = _parent;
    }

    if ( start === undefined ) {
        start = 0;
    }

    self.range = { start: start, end: start, length: 0 };
    self.start = { line: 0, character: 0 };
    self.end = { line: 0, character: 0 };
    self.chunks = [];
    self.markChunkStart( start, false );
}

Position.prototype = {

    markChunkStart: function( pos, propagate ) {
        var self = this;

        self._chunk = { start: pos, end: pos, length: 0 };
        self.chunks.push( self._chunk );

        if ( self._parent && propagate !== false ) {
            self._parent.markChunkStart( pos, propagate );
        }
    },

    markChunkEnd: function( pos, propagate ) {
        var self = this;

        if ( self._chunk ) {
            self._chunk.end = pos;
            self._chunk.length = pos - self._chunk.start + 1;
            delete self._chunk;
        }

        if ( self._parent && propagate !== false ) {
            self._parent.markChunkEnd( pos, propagate );
        }

        return self;
    },

    markEnd: function( pos, propagate ) {
        var self = this;

        self.markChunkEnd( pos, propagate );
        self.range.end = pos;
        self.range.length = pos - self.range.start + 1;

        if ( self._parent ) {
            delete self._parent;
        }

        return self;
    }

};

global.CSSTree.Position = Position;