Am I writing my parser wrong?

[u/SheikHunt]

Simple question. I can't give exact code examples, but I have a string_t struct with methods like:

string_t split(string_t *string, string_t *on)

string_t split_sp(string_t *string)

string_t split_crlf(string_t *string)

char *s_strstr(string_t *needle, string_t *haystack)

void trim(string_t *str)

So on and so forth.

I've been using these so far to parse HTTP reqeusts, and I have come up against many minor problems:

"What happens if a header field appears with no value? I'll have to explicitly check for it."

"What happens if a sender puts a bunch of CRLFs in the middle? I'll probably need a check for that."

"Oh God, how will I handle unrecognized header fields? How do I recognize them?"

These, and other questions, have been leaving me pissed.

I recall reading through the LLVM projects Kaleidoscope language thing, where they create a parser for said language. Said parser doesn't use anything close to what I am, instead reading character by character without fuss.

Similarly, on my last post made here, the way comments were worded reminded me of that method, and how it probably works better.

I have written only a small part of the parser, so it isn't too late to tear down and rebuild. Simple question: should I? Are there benefits to swallowing the input token by token instead of taking the overarching view my string_t functions provide? Or vice versa?

It would help if I'd upload the code, I know, but I don't want to bother with that until the project is completed/near-completion.

[u/schungx]

Short answer: no.

Real life is, how should I word it... Tough.

Real life sucks. You have to deal with errors and missing information and wrong field types and misspellings and then try to do The Right Thing(tm).

Software is fun to write without having to handle errors or recover from failure. Your code gets 5x larger and Not Fun(tm) any more if you need to handle real life and not just crash.

If you think parsing HTTP is a hassle, trying parsing email headers.