Parsing boolean expression without left hand recursion

Question

I\'m trying to match this

f(some_thing) == \'something else\'

• f(some_thing) is a function call, which is an expression

Answer 1

Something like this ought to do it:

expression
 = bool_expression

bool_expression
 = add_expression "==" bool_expression
 / add_expression "!=" bool_expression
 / add_expression

add_expression
 = mult_expression "+" add_expression
 / mult_expression "-" add_expression
 / mult_expression

mult_expression
 = atom "*" mult_expression
 / atom "/" mult_expression
 / atom

atom
 = function_call 
 / string
 / real_number
 / integer
 / identifier

function_call
 = identifier "(" (expression ("," expression)*)? ")"

string
 = "'" [^']* "'"

identifier
 = [a-zA-Z_]+

integer
 = [0-9]+

real_number
 = integer "." integer?
 / "." integer