{

buildTree = function(first, rest) {

if(rest.length == 0) {

return first;

} else {

var next = rest.shift();

var operator = next[0]

var term = next[1]

return {left: first, right: buildTree(term, rest), op: operator};

}

}

}

start

= line

line

= num:line_number? words:word* {

return {'N':num, 'words':words}

}

word = word:letter value:real_value { return [word, value]; }

line_number

= "N" integer

real_value

= factor1

integer

= [0-9]+ { return parseInt(text()); }

number

= [\+\-]?[0-9]+([\.][0-9]+)? { return parseFloat(text()); }

expression

= "[" expr:factor4 "]" {return expr; }

atan_factor = "ATAN" left:expression "/" right:expression {

return {'op':"ATAN", 'left':left, 'right':right};

}

unary_factor = op:unary_op expr:expression {return {'op':op, 'right':expr}}

param_value = "#" expr:(expression / number / param_value) { return {'op':'#', 'right':expr }}

factor1

= expression

/ number

/ atan_factor

/ unary_factor

/ param_value

factor2

= first:factor1 rest:(group1_op factor1)* {

return buildTree(first, rest);

}

factor3

= first:factor2 rest:(group2_op factor2)* {

return buildTree(first, rest);

}

factor4

= first:factor3 rest:(group3_op factor3)* {

return buildTree(first, rest);

}

group1_op = "**"

group2_op = "*" / "/" / "MOD"

group3_op = "+" / "-" / "OR" / "XOR" / "AND"

unary_op = "ABS" / "ACOS" / "ASIN" / "COS" / "EXP" / "FIX" / "FUP" / "ROUND" / "LN" / "SIN" / "SQRT" / "TAN" / "EXISTS"

letter = "A" / "B" / "C" / "D" / "F" / "G" / "H" / "I" / "J" / "K" / "L" / "M" / "P" / "Q" / "R" / "S" / "T" / "X" / "Y" / "Z"