[TUHS] Re: What would early alternatives to C have been?

[Bakul Shah via TUHS <tuhs@tuhs.org>]

Perhaps the interviewer was looking for something dumb like the following
and not a full RD parser?

int count = 0;
while (*cp) {
	char c = *cp++;
	count += c == '(' ? 1 : c == ')' ? -1 : 0;
	if (count < 0) return -1; // FAIL: one too many )
}
if (count > 0) return -1; // FAIL: too many (
return 0; // SUCCESS

Though this will fall apart if you also want to also balance braces &/or
brackets and must catch invalid cases like "(..[..)..]"!

> On Mar 10, 2025, at 8:19 AM, John Cowan <cowan@ccil.org> wrote:
> 
> I was working at the whiteboard during a job interview once. I had been asked to write a function to report if its input had balanced parentheses.  No problem: I wrote an RD parser in Python (which I prefer for whiteboarding) to detect balance and return True if the parse was successful and False if EOF was reached.
> 
> I was starting to write some tests when the interviewer interrupted me.
> 
> "What is that?"
> 
> "It's a recursive descent parser. It detects if the input is well-formed."
> 
> Blank look.
> 
> I started to walk him through the code.
> 
> He interrupted me. "Excuse me, I'll be back in a few minutes."
> 
> Long wait, maybe 15-20 minutes. Someone else comes in. "Thank you, the recruiter will get back to you." That's the last I hear from them.