[Reuseware-users] type casting in composition programs

[Jakob H. <jak...@tu...>]

Hi,

One of the modular xcerpt composers currently look like this (slightly  =

modified from SVN version to show the point):

define composer modularxcerpt.QualifiedQueryTermComposer(moduleName,  =

queryTerm) {

	// Resolve the fragment name into a location (URI, the module ID)
	fragmentlist componentmodel.Location moduleID =3D ->moduleName;

	// Use store: "out"
    	fragmentlist xcerpt.QueryTerm qtWrapper =3D
    		'store [ modul [ <<moduleID>> ], visibility [ "out" ], <<qTerm>>  =

]'.mxcerpt;
	=

	fragmentlist xcerpt.QuotedString quotedModuleID =3D '"' + moduleID  =

+ '"'.mxcerpt;
	bind moduleID on qtWrapper with quotedModuleID;
	=

	// Bind intentional query term to store wrapper
	bind qTerm on qtWrapper with queryTerm;

	// Return store wrapper
	return qtWrapper;
}

The QuotedString quotedModuleID is constructed with a "hack": untyped  =

string concatenation. I want to bind the slot 'moduleID' with the value =
of  =

the fragment moduleID (of type Location). Instead of Lines 10-11, removi=
ng  =

the "hack", I want to write:

bind moduleID on qtWrapper with (xcerpt.QuotedString)moduleID;

Thus casting the type of moduleID from Location to QuotedString (which i=
s  =

possible, since the value of the fragment can be represented both as a  =

Location and as a quoted string). Notice that the '"' of the quoted  =

strings are (should be) just concrete syntax, so they shouldn't be a  =

problem.

Is this a reasonable solution? Can we implement it? Is this relevant to =
 =

Sven's improvements of the composition language?

Let me know what you think.

Cheers,
Jakob
ps. is this the right forum for these kinds of issues? ds.


-- =

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