RE: references and concat

Hi Andrea,

 You can also use the sfGui editor tool to see the different phases and
result steps when parsing a description. It uses a colored syntax and will
help you in finding problems when writing descriptions. You will have to
download and compile it as a separate component from CVS. It will be
included as default in the next packaged release.

You can find it in CVS inside core\extras\sfgui.

Julio Guijarro.

> -----Original Message-----
> From: smartfrog-support-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org [mailto:smartfrog-
> [email protected]] On Behalf Of Goldsack, Patrick
> Sent: 23 June 2004 13:24
> To: 'Andreas Unterkircher'; smartfrog-support-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
> Subject: RE: [Smartfrog-support] references and concat
> 
> 
> Andreas,
> 
> What an excellent example....
> 
> Yes indeed this will not work, and the reason is based on the order of
> resolution.
> 
> The resolution of functions is done AFTER the references are resolved. So
> the reference
> 
>       string4 file1:string3;
> 
> is resolved before the concat function is evaluated. So you then end up
> effectively with:
> 
>       string4 (string1 ++ " and " ++ string2);
> 
> Which, when resolved, cannot resolve string1 and string2 in the new
> location.
> 
> The best way of understanding what is going on is the use the sfParse tool
> to look at all the phases as they occur and the expnasions that result.
> I think the -v option switches this on.
> 
> This is all a result of the way in which the language has had these
> additional features layered on the initial simpler base. The semantics
> have
> some oddities! Language 2, of which I am about to release at least a
> parser
> though not a resolution processor yet, deals with a lot of the semantics
> issues of this kind and produces a clearer definition of what should
> happen.
> 
> However, there are some real semantic questions at the bottom of the
> reason
> for the current semantics which also apply moving forward. If we remember
> that functions are simply component descriptions that are handled at the
> very end as indicating a function, we can simply think about the
> interaction
> of component descriptions and references.
> 
> A component description is a set of attributes which may contain
> references.
> We want to copy the component descriptions (as a result of reference or
> type
> resolution) without resolving these contained references so that if we
> override an attribute value in the copy, the references in the copy will
> now
> resolve using the new value and not refer to the old.
> 
> This seems fine for a "closed" component description - one in which
> references do not map to something outside of the component description
> being copied. Perhps "free" references, those that map out of the CD,
> should
> be bound before copying... (string1 and string2 are free in the component
> description that is string3 in your example). This might be a reasonable
> decision, but expensive to calculate and more complex to implement.
> Consequently, for the moment we re-resolve all references after a copy and
> don't distinguish between free and bound.
> 
> Hope this helps in explaining, even if not in fixing...
> 
> Patrick
> 
> 
> -----Original Message-----
> From: smartfrog-support-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
> [mailto:smartfrog-support-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org] On Behalf Of
> Andreas
> Unterkircher
> Sent: 23 June 2004 12:33
> To: smartfrog-support-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
> Subject: [Smartfrog-support] references and concat
> 
> 
> 
> Hello,
> 
> I encountered one problem concerning resolution and concat of strings. Let
> me illustrate it with a small example (I omit the "#include..."
> statements) consisting of 3 components (file1.sf, file2.sf, file3.sf):
> 
> file1.sf:
> 
> file1 extends {
>  string1 "string1 in file1";
>  string2 "string2 in file1";
>  string3 (string1 ++ " and " ++ string2);
> }
> 
> file3.sf
> 
> sfConfig extends Compound {
>  a extends file1;
> }
> 
> This works fine, "sfParse file3.sf" yields:
> 
> sfCodeBase "default";
> sfClass "org.smartfrog.sfcore.compound.CompoundImpl";
> a extends  {
> 	string1 "string1 in file1";
> 	string2 "string2 in file1";
> 	string3 "string1 in file1 and string2 in file1";
> }
> 
> SFParse: SUCCESSFUL
> 
> Now I introduce a component file2:
> 
> file2 extends {
>  string4 file1:string2;
> }
> 
> I change file3 to:
> 
> sfConfig extends Compound {
>  a extends file2;
> }
> 
> This works also fine, "sfParse file3.sf" yields:
> 
> Parser - SmartFrog 3.02.002_beta
> (C) Copyright 1998-2004 Hewlett-Packard Development Company, LP
> 
> sfCodeBase "default";
> sfClass "org.smartfrog.sfcore.compound.CompoundImpl";
> a extends  {
> 	string4 "string2 in file1";
> }
> 
> SFParse: SUCCESSFUL
> 
> Now I change file2 to reference the concateneted string from file1:
> 
> file2 extends {
>  string4 file1:string3;
> }
> 
> This doesn't work, "sfParse file3.sf" yields:
> 
> Parser - SmartFrog 3.02.002_beta
> (C) Copyright 1998-2004 Hewlett-Packard Development Company, LP
> 
> ERROR 'file3.sf':
> SmartFrogCompileResolutionException:: Unresolved Reference, data: [string1
> in: HERE sfConfig:a:string4, string2 in: HERE sfConfig:a:string4], source:
> HERE sfConfig, resolutionPhase: link
> 
> Error detected. Check report.
> SFParse: FAILED
> 
> Why doesn't this work ?
> 
> Thanks,
> Andreas
> 
> --
> http://cern.ch/openlab
> 
> 
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