gistfile1.txt

sum -> sum "+" product {% d => d[0] + d[2] %}
		| sum "-" product {% d => d[0] - d[2] %}
		| product {% d => d[0] %}
product -> product "*" factor {% d => d[0] * d[2] %}
		| product "/" factor {% d => d[0] / d[2] %}
		| factor {% d => d[0] %}
factor -> "(" sum ")" {% d => d[1] %}
		| float {% d => d[0] %}
float -> num "." num {% d => parseFloat(d[0] + d[1] + d[2]) %}
		| num  {% d => parseInt(d[0]) %}
num -> [0-9]:+ {% d => d[0].join('') %}