svgPathGrammer.js

var svgPathGrammerFunction = function() {
/* svg_path
  = wsp* data:moveTo_drawTo_commandGroups? wsp*
  {
    var result = [];
    function flatten(a){
      for (var i=0,l=a.length;i<l;++i){
        var o=a[i];
        if (o.constructor==Array) flatten(o);
        else if (o && o!=" ") result.push(o);
      }
    }
    flatten(data);
    return result;
  }

moveTo_drawTo_commandGroups
  = first:moveTo_drawTo_commandGroup more:(wsp* moveTo_drawTo_commandGroups)?

moveTo_drawTo_commandGroup
  = first:moveto wsp* more:drawto_commands?

drawto_commands
  = first:drawto_command more:(wsp* drawto_commands)?

drawto_command
  = closepath
    / lineto
    / horizontal_lineto
    / vertical_lineto
    / curveto
    / smooth_curveto
    / quadratic_bezier_curveto
    / smooth_quadratic_bezier_curveto
    / elliptical_arc


moveto
  = c:[Mm] wsp:wsp* seq:moveto_argument_sequence 
    { return {command:"moveto", relative:c=='m', args:seq} }

moveto_argument_sequence
  = first:coordinate_pair more:(comma_wsp? lineto_argument_sequence)?
  { for (var a=[first],i=1,len=more.length;i<len;++i){ a[i]=more[i][0] }; return a; }


closepath
  = [Zz]
    { return {command:"closepath" } }

lineto
  = c:[Ll] wsp* args:lineto_argument_sequence
  { return {command:"lineto", relative:c=='l', args:args} }

lineto_argument_sequence
  = first:coordinate_pair more:(comma_wsp? lineto_argument_sequence)?
  { for (var a=[first],i=1,len=more.length;i<len;++i){ a[i]=more[i][0] }; return a; }

horizontal_lineto
  = c:[Hh] wsp* args:coordinate_sequence
  { return {command:"horizontal lineto", relative:c=='h', args:args} }

coordinate_sequence
  = first:coordinate more:(comma_wsp? coordinate_sequence)?
  { for (var a=[first],i=1,len=more.length;i<len;++i){ a[i]=more[i][0] }; return a; }

vertical_lineto
  = c:[Vv] wsp* args:coordinate_sequence
  { return {command:"vertical lineto", relative:c=='v', args:args} }


curveto
  = c:[Cc] wsp* args:curveto_argument_sequence
  { return {command:"curveto", relative:c=='c', args:args} }

curveto_argument_sequence
  = first:curveto_argument more:(comma_wsp? curveto_argument_sequence)?
  { for (var a=[first],i=1,len=more.length;i<len;++i){ a[i]=more[i][0] }; return a; }

curveto_argument
  = a:coordinate_pair comma_wsp? b:coordinate_pair comma_wsp? c:coordinate_pair
  { return { x1:a.x, y1:a.y, x2:b.x, y2:b.y, x:c.x, y:c.y } }


smooth_curveto
  = c:[Ss] wsp* args:smooth_curveto_argument_sequence
  { return {command:"smooth curveto", relative:c=='s', args:args} }

smooth_curveto_argument_sequence
  = first:smooth_curveto_argument more:(comma_wsp? smooth_curveto_argument_sequence)?
  { for (var a=[first],i=1,len=more.length;i<len;++i){ a[i]=more[i][0] }; return a; }

smooth_curveto_argument
  = b:coordinate_pair comma_wsp? c:coordinate_pair
  { return { x2:b.x, y2:b.y, x:c.x, y:c.y } }


quadratic_bezier_curveto
  = c:[Qq] wsp* args:quadratic_bezier_curveto_argument_sequence
    { return {command:"quadratic curveto", relative:c=='q', args:args} }

quadratic_bezier_curveto_argument_sequence
  = first:quadratic_bezier_curveto_argument more:(comma_wsp? quadratic_bezier_curveto_argument_sequence)?
  { for (var a=[first],i=1,len=more.length;i<len;++i){ a[i]=more[i][0] }; return a; }

quadratic_bezier_curveto_argument
  = a:coordinate_pair comma_wsp? b:coordinate_pair
  { return { x1:a.x, y1:a.y, x:b.x, y:b.y } }


smooth_quadratic_bezier_curveto
  = c:[Tt] wsp* args:smooth_quadratic_bezier_curveto_argument_sequence
  { return {command:"smooth quadratic curveto", relative:c=='t', args:args} }

smooth_quadratic_bezier_curveto_argument_sequence
  = first:coordinate_pair more:(comma_wsp? smooth_quadratic_bezier_curveto_argument_sequence)?
  { for (var a=[first],i=1,len=more.length;i<len;++i){ a[i]=more[i][0] }; return a; }


elliptical_arc
  = c:[Aa] wsp* args:elliptical_arc_argument_sequence
  { return {command:"elliptical arc", relative:c=='a', args:args} }

elliptical_arc_argument_sequence
  = first:elliptical_arc_argument more:(comma_wsp? elliptical_arc_argument_sequence)?
  { for (var a=[first],i=1,len=more.length;i<len;++i){ a[i]=more[i][0] }; return a; }

elliptical_arc_argument
  = rx:nonnegative_number comma_wsp? ry:nonnegative_number comma_wsp? 
        xrot:number comma_wsp large:flag comma_wsp? sweep:flag comma_wsp? xy:coordinate_pair
  { return { rx:rx, ry:ry, xAxisRotation:xrot.join('')*1, largeArc:large=='1', sweep:sweep=='1', x:xy.x, y:xy.y } } 


coordinate_pair
  = x:coordinate comma_wsp? y:coordinate
  { return { x:x, y:y } }

coordinate
  = n:number
  { return n.join('')*1 }

nonnegative_number
  = integer_constant / floating_point_constant

number
  = sign? integer_constant
    / sign? floating_point_constant

flag
  = "0" / "1"

comma_wsp
  = (wsp+ comma? wsp*) / (comma wsp*)

comma
  = ","

integer_constant
  = digit_sequence

floating_point_constant
  = fractional_constant exponent?
    / digit_sequence exponent

fractional_constant
  = digit_sequence? "." digit_sequence
    / digit_sequence "." { return "hi" }

exponent
  = [eE] sign? digit_sequence

sign
  = "+" / "-"

digit_sequence
  = digits:[0-9]+
    { return digits.join("")*1 }

wsp
  = [ \t\n\r] */
}

var convertToGrammer = function (f) {
  return f.toString().
      replace(/^[^\/]+\/\*!?/, '').
      replace(/\*\/[^\/]+$/, '');
};

var svgPathGrammer = convertToGrammer(svgPathGrammerFunction);

var peg = require('pegjs');

exports.pathParser = peg.buildParser(svgPathGrammer);