can I select over functions?

Marc van Woerkom <>
Fri Jun 11 10:19:26 CEST 2004


Am Thu, 10 Jun 2004 23:23:49 +0200 hat
"Robert Virding" <> geschrieben:
>From: "Marc van Woerkom" 
><>
>> The pseudo code in the icfp contest task had some piece
>> like
>>
>>     case instruction of
>>       move(Ant, Steps) ->
>>          ..
>>       turn(LeftRight) ->
>>          ..
>>       sense(Direction, Time, Moonphase) ->
>>          ..
>>     end
>>
>> where the different cases are not simple values like a
>> token for the intended instruction, but functions.
>
>What are you actually trying to do here, compare 
>Instruction with the actual
>functions (i.e. it is a function) or compare it with the 
>values of the
>evaluated functions?

Intendend is comparison of functions,
maybe

      case instruction of
        move/2 ->
           ..
        turn/1 ->
           ..
        sense/3 ->
           ..
      end

would be closer to the Erlang spirit.

> The name(...) syntax means a 
>function call. There is no
>real way of defining a function object except with fun's 
>and comparing funs
>works but is limited.

May you tell me how that comparison of functions (or is 
'fun' limited to anonymous functions) looks like?
I did not spot it when I looked for it.

Regards,
Marc



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