format parser, add support for negative integers and return specifically

which type of number

src/parser/grammar.pegjs

@@ -269,6 +269,7 @@ ArithmeticOperation
   / "/"
   / "*"
   / "**"
+  / "%"
 
 BitOperation
   = ">>"
@@ -285,17 +286,17 @@ ComparisonOperation
   / ">"
   / "<"
 
-Integer = digits:[0-9]+ !"." { return parseInt(digits.join(''), 10); }
+Integer = digits:("-"? [0-9]+) !"." { return { int: parseInt(digits.join(''), 10) }; }
 
 QuotedString
   = "'" content:[^']* "'" { return content.join(''); }
   / "\"" content:[^"]* "\"" { return content.join(''); }
 
 Real
-  = value:("-"? [0-9]+ "." [0-9]+) {
-      return parseFloat(
+  = value:("-"? [0-9]+ ("." [0-9]+)?) {
+      return { real: parseFloat(
         value.map(x => (Array.isArray(x) ? x.join('') : x)).join(''),
-      );
+      ) };
     }
 
 Literal