Re: [gobo-eiffel-develop] Catcall in gec

[Wolfgang J. <wj...@so...>]

Eric Bezault wrote:
> Wolfgang Jansen wrote:
>> Hi,
>>
>> when experimenting with classes of the GEC it happens
>> that compilation fails because of a catcall.
>> To be precise, let `f' be a ET_DYNAMIC_FEATURE
>> then adding the line
>>
>>    if f.static_feature.name.name.is_equal("abc") then ... end
>>
>> leads to compiler message
>>
>> [CATCALL] class ET_C_GENERATOR (17182,4): type 'STRING_8' of actual
>> argument #1 does not conform to type 'UC_UTF8_STRING' of formal 
>> argument in feature `is_equal' in class 'UC_UTF8_STRING'
>
> Yes, the signature of `is_equal' is a real problem when
> we want to be CAT-call free. The workaround is to inherit
> from KL_IMPORTED_STRING_ROUTINES and write:
>
>   if STRING_.same_string (f.static_feature.name.name, "abc") then
>
> Another solution:
>
>   if f.static_feature.name.same_feature_name (create 
> {ET_IDENTIFIER}.make ("abc")) then
>
>
>> A similar catcall occurs if a DS_HASH_TABLE[INTEGER,STRING]
>> object is created (a call at the object is not needed).
>
> For hash-tables, you need to create them that way in order
> to be CAT-call free:
>
>   create ht.make_map (...)
>   ht.set_key_equality_tester (string_equality_tester)
>
> or:
>
>   create ht.make_with_equality_testers (..., Void, 
> string_equality_tester)
>
> where `string_equality_tester' is inherited from
> KL_SHARED_STRING_EQUALITY_TESTER.
>
>
Thanks, it works (though it is hard to understand).

-- 
Wolfgang Jansen
University of Potsdam, Germany
mailto: wj...@so...