I know we are sponsoring This... But it sounds to me like so much work and so little gain. Sure, the current parse thing is slow and buggy, but only a few minor bugs and performance gain Will be limited as well. I think looking at 3th party parsers isn,'t a bad idea at All.
Sent from my Windows Phone ________________________________ From: Jiří Činčura<mailto:j...@cincura.net> Sent: 6/10/2015 6:38 To: For users and developers of the Firebird .NET providers<mailto:firebird-net-provider@lists.sourceforge.net> Subject: Re: [Firebird-net-provider] Parser class/library On Mon, Oct 5, 2015, at 21:32, Michał Ziemski wrote: > IMHO you won't be able to handle all the corner cases without full > grammar > parser. Well, the cases we need are not that wide. But it's tedious anyway. > For example consider a "SET TERM" inside an "EXECUTE BLOCK". > Lacking the grammar understnding you won't recognize that as an invalid > term in the execute block and > you'll simply cut the block in half. So the decision is how far do you I don't care much about invalid scripts. It fails either way. But I agree that it's at least confusing for people consuming the library. > want > to go. Personally, not far. :) There's way more interesting pieces. > Writing a full scale parser for FB SQL in a rather easy but very tedious > and time-consuming task. > Having that as a tool would be a great addition to FB ecosystem. > The parser in FB itself is written in yacc so it's faily transportable. > Sill you'll have to go rule by rule > and convert to C#. > Actually I have tried this myself in F# (it's far far better suited for > parsers) and am about 50% through. > I would gladly donate the code if you'd be interested. I don't think it will hurt. > If you would preffer the faster approach I would suggest: > - a simple lexer by hand that recognizes tokens "SET" "TERM" > CURRENT_TERM_SYMBOL "--" , NEWLINE OTHER_TOKEN and STRING > - a parser that iterates the tokens form lexer, tests for sequences: > "SET" "TERM" OTHER_TOKEN CURRENT_TERM_SYMBOL - to set new terms > CURRENT_TERM_SYMBOL - to yield accumulated OTHER_TOKENs and STRINGs > - -- to start a comment and skip everything till NEWLINE > this should be an easy enough state machine to write by hand. That's what I'm currently doing. Sadly. -- Mgr. Jiří Činčura Independent IT Specialist ------------------------------------------------------------------------------ _______________________________________________ Firebird-net-provider mailing list Firebird-net-provider@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/firebird-net-provider
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