cor-lang/src/sourcemap.js

The Language of the Web

(function(cor){

// This is a version,
// the original code can be found at
// https://github.com/jashkenas/coffeescript/tree/master/src/sourcemap.litcoffee

var
Class                = cor.Class,
VLQ_SHIFT            = 5,
VLQ_CONTINUATION_BIT = 1 << VLQ_SHIFT,
VLQ_VALUE_MASK       = VLQ_CONTINUATION_BIT - 1,
BASE64_CHARS         = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';

function toVlq(value) {
    var nextChunk,
    vlq           = '',
    signBit       = value < 0 ? 1 : 0,
    valueToEncode = (Math.abs(value) << 1) + signBit;

    while (valueToEncode || !vlq) {
        nextChunk     = valueToEncode & VLQ_VALUE_MASK;
        valueToEncode = valueToEncode >> VLQ_SHIFT;

        if (valueToEncode) {
            nextChunk |= VLQ_CONTINUATION_BIT;
        }

        vlq += toBase64(nextChunk);
    }
    return vlq;
};

function toBase64(value) {
    var
    b64 = BASE64_CHARS[value];

    if (! b64) {
        throw 'Can not encode ' + value + ' to base-64';
    }
    return b64;
}

var
LineMap = Class({

    line    : null,
    segments: null,

    init: function(l) {
        this.line    = l;
        this.segments = [];
    },

    add: function(generatedColumn, sourceLine, sourceColumn) {
        this.segments[generatedColumn] = {
            line        : this.line,
            column      : generatedColumn,
            sourceLine  : sourceLine,
            sourceColumn: sourceColumn
        };

        return this.segments;
    }
});

var
SourceMap = Class({

    lines: null,

    names: null,

    init: function() {
        this.lines  = [];
        //this.names  = [];
    },

    add: function(sourceLine, sourceColumn, generatedLine, generatedColumn) {
        var
        line = this.lines[generatedLine];

        if (! line) {
            line = this.lines[generatedLine] = new LineMap(generatedLine);
        }

        line.add(generatedColumn, sourceLine, sourceColumn);
    },

    generate: function(config) {
        config = config || {};

        var i, j, line, sm,
        segment, segmentsLen,
        currentLine      = 0,
        lastSourceLine   = 0,
        lastSourceColumn = 0,
        lastColumn       = 0,
        linesLen         = this.lines.length,
        mapping          = '',
        segmentSep       = '';

        for (i = 0; i < linesLen; i++) {
            line = this.lines[i];

            if (! line) { continue }

            segmentsLen = line.segments.length;

            for (j = 0; j < segmentsLen; j++) {
                segment = line.segments[j];

                if (! segment) { continue }

                while (currentLine < segment.line) {
                    segmentSep = '',
                    lastColumn = 0;
                    mapping    += ';';
                    currentLine++;
                }

                mapping += segmentSep;
                mapping += toVlq(segment.column - lastColumn);
                mapping += toVlq(0);
                mapping += toVlq(segment.sourceLine - lastSourceLine);
                mapping += toVlq(segment.sourceColumn - lastSourceColumn);

                lastColumn       = segment.column;
                lastSourceLine   = segment.sourceLine;
                lastSourceColumn = segment.sourceColumn;

                segmentSep = ',';
            }
        }

        sm = {
            version       : 3,
            file          : '',
            sourceRoot    : '',
            sources       : [''],
            sourcesContent: [null],
            names         : [],
            mappings      : mapping
        };

        if (config.file) {
            sm.file = config.file;
        }

        if (config.sourceRoot){
            sm.sourceRoot = config.sourceRoot;
        }

        if (config.source) {
            sm.sources = [config.source];
        }

        if (config.sourceContent) {
            sm.sourcesContent = [config.sourceContent];
        }

        return JSON.stringify(sm);
    }
});

cor.SourceMap = SourceMap;

})(typeof cor === 'undefined' ? {} : cor);