omoikane_test.js

var grammar = `
Expression
  = Scalar
  / GeneralVectorExpr

GeneralVectorExpr
  = head: GeneralVector tail: (_ ("+" / "-") _ GeneralVector) * {
      return head;
}

GeneralVector
  = BracketedList
  / "(" _ list: ScalarList _ ")" { return list; }

BracketedList
  = "[" _ list: ScalarList _ "]" { return list; }
  / "[" head:BracketedList tail:(_ "," _ x:BracketedList)* "]"
{
      var result =[head];

      for (var i = 0; i < tail.length; i++) {
        if (tail[i][3].length != head, length) {
          throw "jaggy matrix";
}
        result[1 +i]= tail[i][3];
}

      return result;
}

ScalarList
  = head: Scalar tail: (_ "," _ Scalar) * {
      var result =[head];

      for (var i = 0; i < tail.length; i++) {
        result[1 +i]= tail[i][3];
}

      return result;
}

Scalar
  = head: Term tail: (_ ("+" / "-") _ Term) * {
      var result = head;

      for (var i = 0; i < tail.length; i++) {
        if (tail[i][1]=== "+") { result += tail[i][3]; }
        if (tail[i][1]=== "-") { result -= tail[i][3]; }
}

      return result;
}

Term
  = head: Factor tail: (_ ("*" / "/") _ Factor) * {
      var result = head;

      for (var i = 0; i < tail.length; i++) {
        if (tail[i][1]=== "*") { result *= tail[i][3]; }
        if (tail[i][1]=== "/") { result /= tail[i][3]; }
}

      return result;
}

Factor
  = "(" _ expr: Scalar _ ")" { return expr; }
  / Integer

Integer "integer"
  =[0-9]+{ return parseInt(text(), 10); }

_ "whitespace"
  =[ \\t\\n\\r]*
`;

var parser = peg.generate(grammar);

function stringify(value)
{
	if (Array.isArray(value))
	{
		return value.toSource();
	}
	return value.toString();
}

var testcase = {
	"1": 1,
	"1 + 2": 3,
	"1 + 2 * 3": 7,
	"(1 + 2) * 3": 9,
	"(1, 2, 3)": [1, 2, 3],
	"[1, 2, 3]": [1, 2, 3],
	"[[1, 2], [3, 4]]": [[1, 2], [3, 4]],
	"2 * [1, 2]": [2, 4],
};

$(function ()
{
	for (key in testcase)
	{
		var result;
		try {
			result = stringify(parser.parse(key));
		} catch(e) {
			result = "!!! " + e + " !!!";
		}
		var expected = stringify(testcase[key]);

		var row = $("<div>").addClass("row");
		row.append($("<div>").addClass("cell").text(key));
		row.append($("<div>").addClass("cell").addClass(result == expected ? "test_ok" : "test_fail").text(result));
		row.append($("<div>").addClass("cell").text(expected));
		$("#area").append(row);
	}
});