Re: Discriminated records are not the most efficient, but ...

["Yannick Duchêne (Hibou57)" <yannick_duchene@yahoo.fr>]

Le Sun, 22 Aug 2010 07:39:45 +0200, Yannick Duchêne (Hibou57)  
<yannick_duchene@yahoo.fr> a écrit:
> (here, the underscore “_” has the same meaning as with Prolog)
This “_” is nice for analysis, as it explicitly state a given component of  
a structure is not used in a given branch of a recursive algorithm (or  
even not recursive). I feel this help to express clean analysis.

Funny: I came to an SML tutorial containing a whole paragraph talking  
about Ada and how some SML constructs can be mapped to Ada. It said (they  
seemed to like Pascal and Algol also):

   Roughly speaking (that is their wording)
    * Structures in ML corresponds to Package in Ada
    * Signature corresponds to an Ada Package Interface
    * Functor corresponds to Generic Package in Ada

But they was wrong in one point, as they also ended with:

    “However, ML admits structures (not just types) as parameters to  
functors.”

Probably they never heard about “package formal parameter”. I suppose they  
knew about Ada 83 and this was not there with this one (but was this  
really the case ?)

They also forget about discriminated records (but they did not claim their  
match/match list was exhaustive).