Re: Text parsing package

["Yannick Duchêne (Hibou57)" <yannick_duchene@yahoo.fr>]

Le Wed, 23 Mar 2011 09:32:10 +0100, Dmitry A. Kazakov  
<mailbox@dmitry-kazakov.de> a écrit:
> 1. Don't use unbounded strings. That is an unnecessary overhead.
Yes, better limit the maximum size of literals.

> 3. As others have mentioned, it is a good idea to abstract the source
> formats in order to be able to parse files, strings, streams etc.
And Ada already provides a root for that: Ada.Streams.Root_Stream_Type

> 6. You should decide what drives the parser. In your case it is the  
> caller.
> That is not a good idea in most cases, because the caller rarely knows  
> what
> to expect next. A better choice is semantic call-backs from the parser to
> the caller. Abstract primitive operations is IMO the best implementation  
> of
> such callbacks.
What “drives”, is not just a question rising with parsers, it is rising  
every where. Here, if Ada had something like a Yield, this would be nice  
too. Otherwise, yes, the callback is a good choice and may allow  
optimization, especially if some kind of seeking into the source is an  
expected option (the parser can then efficiently skip what is not  
relevant; on the opposite, if the caller drives, then no such optimization  
is possible).


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