Re: [Boost-users] Boost::Spirit - Just enough to match a term?

From: Stuart Dootson (stuart.dootson_at_[hidden])
Date: 2006-07-12 12:34:03

On 7/12/06, Eric Hill <eric_at_[hidden]> wrote:
> I'm past the initial learning curve with Spirit, but would like to see how
> the pros handle this problem.
>
> I have the following simple command structure:
>
> show queues
> show users
> show processes
> start process foo
> queue user bar to process foo
> ...etc
>
> I would like to parse these commands with Spirit.  Easy enough.  Since
> this is being entered from a keyboard, it would be nice to short-circuit
> the parser so you only have to enter enough of the command for the parser
> to reliably figure out what you want.
>
> e.g. "sh qu" would parse as "show queues", and "st pr foo" would parse as
> "start process foo".
>
> I can easily model the whole "show queues" command word with:
>
> str_p("show") >> str_p("queues")
>
> But how do I match "just enough" instead of "whole word" without doing it
> manually?
>
> TIA,
> Eric
>

There's nothing built in to do that (AFAIK). However, it is relatively
trivial to implement using a functor parser. I've done it myself -
however, the code's at work, and I'm not :-) I'll post some code
tomorrow after work (haven't got access to this e-mail account
there!).

Anyway, the strategy I followed was to initialise the functor parser
with a set of tokens and it would generate the set of unambiguous
prefixes. Then the functor parser would match tokens that matched the
required words to sufficient length.

Stuart Dootson

Stuart Dootson