Is the ANTLR parser generator best for a C++ app with constrained memory?

Question

I\'m looking for a good parser generator that I can use to read a custom text-file format in our large commercial app. Currently this particular file format is read with a handm

Answer 1

A hand-coded recursive descent parser is actually quite fast and can be very compact. The only downside is you have to be careful to code essentially LL(1) grammars. [If you use ANTLR, you have similar restrictions so this isn't that big a deal].

You can hand code such parsers as plain recursive C code. (See this answer for complete details: Is there an alternative for flex/bison that is usable on 8-bit embedded systems?)

If you are really tight on space, you can define a parsing virtual machine, and build a tiny C interpreter to run it. I used to build BASIC interpreters this way back in the early 70s.

By sticking to the very simple conventions that make these parsers actually work, you can guarantee that there is no memory leak caused by the parsing machinery. (Of course, you may attach arbitrary actions to the parser where it recognizes items of interest; whether those actions leak is a matter of general programming, not the parser).

The ideas came from a 1964 paper on metacompilers by Val Schorre, who shows how to build complete compilers in 10 pages. Shorre's tiny parser generator produces pretty good recursive descent parsers. A site describing this paper and showing precisely how to build such parsers can be found at http://www.bayfronttechnologies.com/metaii.html

I used Schorre's methods to build Basic compilers in the late 70s, after I got tired of hand-coding complex grammars.