how YOU parse files

How do you like to parse files? Do you load or mmap the entire thing into memory and manipulate pointers, or do you load in bits and pieces with stream IO? Do you try to operate on the data in its native format, or do you convert everything into a format that is easier for you to handle? Do you fastidiously check for malformed input, or do you throw caution to the wind?

Load it in blocks, if possible, to not waste shittons of memory. Fill in structures designed for efficient manipulation and also such that functions that operate it don't have to do special operations to get to the data itself. Accept most things, but output a strict standard.

I parse files with regex.

s-expressions and READ. Why the fuck would you dick with anything manual?

i've never done the mmap thing, sounds kind of cool

It Depends.