THANKS ONCE MORe!

Well, first of all Coco itself is not really my work, so I don’t know all the thinking behind it. But as for my opinion, I don’t really understand the problem you’re having:

1. Several applications for one grammar. What are these applications doing? Why don’t you parse your input into an abstract syntax tree (or some other datastructure) and then let your applications work on that datastructure? What kind of application code are you talking about?

2. Dotted identifiers and dots inside strings. Are you talking standard quoted strings here, e.g. “hello. World”? If so, that string is one token, so the fact that there is a token inside it doesn’t matter.

But in general, yes, I could see where state could become an issue for example parsing a php file where on one hand you have everything inside <? ?> which has its own token rules but on the other hand you’re parsing the html outside those tokens.

I used Coco and the plugin a bit more, but am now close to stop using it. The plugin is fine, but what I was sceptical of ever since, is that since the establishment of lex like tool chains, people write their application code into the grammar files. Studying the .ATG samples for the C# parser a bit more, revealed to me, that it also contains a hand written scanner.
And this is exactly what ails me in my project: I have /several/ applications for the same grammar, not just one, so mixing application and grammar is a bit of a no no for me.
Also, the standard scanner is a single state automaton, which makes it harder to get useful semantic actions attached.
Theory says, not without reason, that a scanner is a FSM (Finite state machine), as it needs to be context sensitive as to the state of the parser.
Example:
You have doted identifiers (e.g. namespaces) and you have strings, which might contain dots. The naive approach would be cumbersome, as the Scanner would split the string within the “” delimiters, as there is also the dot token, the scanner recognizes.
I tend more and more to return to my traditional way of tackling my task, using the parser composition approach (see boost/spirit for the idea, while I do it in simpler style in C#). With that, there is no factored out scanner and the state of the parser naturally is coupled to the way, the scanner operates.
I know, this is probably not the right forum, but I would be interested in a discussion about the question, as to whether a seperated scanner is truly a good idea.

SomeProduction
= (. SomeProductionBegin(); .)
// more “hooks” at each position where a match happens, (so data can be extracted).
(. SomeProductionEnd(); .)
.

Users would then simply implement the partial functions they are interested in in a third .cs partial class part.

Do you have particular hooks in mind that you think would be useful here?

There is also now an “official” Coco/R plugin for VS (at least made at the same institute that makes Coco/R), however I don’t know exactly what approach they take as I’ve never tried it.

Is it only me? The partial classes approach is great and as it should be done!
But…would it not be better to declare partial “hook” functions in the generated code files as well, as well as calling them in the appropriate spots during parsing, so a (third?) partial file could contain the implementations, such that regenerating does not affect the hand written code?

Thanks again.
Pavel K.

Glad you could use the tool. Unfortunately you can’t really change the frame file without re-compiling the plugin since the frame files are embedded in the CocoPlugin.dll file. Maybe not the best decision I made there…

But you can if you want check out the source from Subversion at http://einaregilsson.googlecode.com/svn/dotnet/CocoPlugin/

Then change the Scanner.frame file in the Frames folder and rebuild the .dll. You don’t need to rebuild the installer or anything, just build the dll and dump it in \Visual Studio 200X\AddIns or something like that, where the old CocoPlugin.dll is.

If that doesn’t work for you for some reason then just let me know exactly how you want the line to read (” = new Dictionary“) and I’ll do a custom build for you.