The body of the function to validate.
true if the function has correct syntax, false otherwise.
dstring func = "x + 1"d; assert(validateFunction(func)); func = "x^^2 + 2^^2 j- 3"d; assert(!validateFunction(func)); func = "x.3"; assert(!validateFunction(func)); func = "()"; assert(!validateFunction(func)); func = "x ^ 3"; assert(!validateFunction(func)); func = "x +"; assert(!validateFunction(func)); assert(!validateFunction("x ++ 1"d));
Validates the math library's fucntion syntax.
TODO: Make syntax rules modular.