jawher on Parsing command line arguments using a finite state machine and backtracking

Comment on Parsing command line arguments using a finite state machine and backtracking parent

Parser combinators would certainly have been easier for me, the library author but not necessarily so for the end user.

Contrast how it is done now:

  [-R [-H | -L | -P]] [-fi | -n] [-apvX] SRC... DST

With a parser combinator based approach:

  and(
    optional(and('-R', or('-H', '-L', '-P'))),
    optional(or(
                '-fi', 
                '-n'
             )
    ),
    optional('-apvX'),
    repeatable('SRC'),
    'DST')

And this didn't even handle the fact that options order is not important.

jpdarago 11y

For that I think you can do something similar to what mpc for C (https://github.com/orangeduck/mpc) and LPeg for Lua (http://www.inf.puc-rio.br/~roberto/lpeg/), which is to provide the parsing machinery and write a small DSL with the same machinery for the users.

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