[Newbies] How to know where a BlockClosure finish

[Mathieu]

Marcus Denker a écrit :
>>
>> Yes you are right
>>
>> In the script I have 2 kind of things:
>> [
>> some Smalltalk
>> ]
>>
>> And:
>>
>> Class selector
>> [
>> some smalltalk
>> ]
>>
>> So my idea was to call Compiler>>#evaluate:in:to:notifying:ifFail:logged:
>> on the string inside the [] for the first things.
>>
> 
> Hi Mathieu,
> 
> I would go for a "complete" compiler for this... so let's explain a bit.
> (Hmm,
> Compilers, Parsers, Code Generation. Perfect Newby topics :-)
> 
> So: If we look at the new compiler in Squeak, it works on single
> methods. For
> each method, it does
>     - Scann / Parse to build up a Tree of objects that describe the code
>       The root of the tree is RBProgramNode. (other node are e.g.
> RBSendNode,
>       RBVariableNode... things like that).
>     - Analyze the names of variables. The AST only known that "a" is a
> name... but it
>       does not know what it means.. so is this a definition of a temp? Or
>       a use of an existing temp? Or an iVar?. This analysis is done in the
>       class ASTChecker
>     - Code Generation. The analyzed AST is visited by the ASTTranslator
>       to build a CompiledMethod obiect (using IRBuilder). This then is
> installed
>           in a class.
> 
> Ok. So for your Scripting system I would do the same:
> 
> 1) Scann/Parse the input, build up a Tree
> 2) Analyse the tree (name analysis)
> 3) generate all the needed elements (methods, classes)
> 4) run.
> 
> 1) Scann/Parse.
> 
> Just re-use the existing Parser, extend the grammar to not parse one
> method, but a whole Script. The root-node of the AST would then be
> some "SqueakScriptNode". This has nodes for all classes that the
> script defined, and nodes for all methods (these will be normal
> RBMethodNodes).
> Then it has the code of the script that starts the whole thing as a special
> method (named #run).
> 
> Keep in mind that this Tree-Representation of the Script has not yet added
> any methods or classes to the system.
> 
> 2) Analyse. The RBMethodNodes needs to have the ASTChecker run so
>      all variables are bound correctly.
>     This pass could do other analysis things, if needed (don't know any)
> 
> 3) Generation.
> Now we need to go through the Tree and generate the smalltalk things
> described in it. E.g. classes that are defined need to be created, we need
> to generate code from the RBMethodNodes and install the resulting
> CompiledMethod objects in the methodDict of the class that they are
> defined for.

 Yes And I think we have to remove them at the end of the script.

> 
> The code at the end of the script that is just run will be made a
> CompiledMethod,
> too. For the Script itself, at the beginnig it would be just a method
> that does
> not get installaled but just run.
> Later it might be interesting to have a "SqueakScript" object that is
> kind of like
> a Class but has no name... it could contain helper methods for parsing e.g.
> the command line, stuff like that. This could be implemented as a subclass
> of Behavior. The run method then would be installed in am instance of that.
> 
> Hmm... Now I fear we are completely out of the Beginners' realm ;-)
> 
> Please ask if you need more explanations... I'm sure this was a  much
> too short
> explanation.
> 
>    Marcus
> 

:)
Thanks a lot Marcus, it's very interesting
, sure I have plenty of question but for the time being let's apply the
1) and 2).

Math