This is pulse width codec for PEG.js

pwc_PEG

program_unit "程序"
= desc_unit+





desc_unit "描述单元"
= param:desc_unit_primitive+";"
  {
   return param;
  }






desc_unit_primitive "描述单元中的基础单元"
//
 = desc_unit_ref

/  pulse_seq_unit

/  pulse_global_unit

//循环运算
/ param1:integer"*" param2:desc_unit_ref
 {
  return {
   typ:"Repeat",
   cnt:param1,
   val:param2
  }
 }

//循环运算
/ param1:integer"*" param2:pulse_seq_unit
 {
  return {
   typ:"Repeat",
   cnt:param1,
   val:param2
  }
 }


//循环运算
/ param1:integer"*" param2:pulse_global_unit
 {
  return {
   typ:"Repeat",
   cnt:param1,
   val:param2
  }
 }



desc_unit_ref "描述单元引用"
 = "["param:integer"]"
   {
    return {
     typ:"DescUnitRef",
     val:param
    };
   }


pulse_seq_unit "波形单元"

 = "("param1:pulse_and* param2:pulse")"
   {
    var ret = param1;
    ret.push(param2);
    return {
     typ:"PulseSeq",
     val:ret
    };
   }


pulse_global_unit "全局波形单元"
 = "<"param:pulse">"
   {
    return {
     typ:"PulseGlb",
     val:param
    };
   }





pulse_and
=
  param:pulse","
   {return param;}



pulse "Pulse"

 = "+"param:integer 
   {
    return {s:1,w:param};
   }

   /"-"param:integer 
   {
    return {s:-1,w:param};
   }

   /param:integer
   {
    return {s:0,w:param};
   }




integer "Integer"
  = digits:[0-9]+ { return parseInt(digits.join(""), 10); }