On 04/03/2013 14:49, Sven Barth wrote:
Am 04.03.2013 15:42, schrieb Martin:
but (4) is powerful enough to really make functional-style programming
practically
I can live with that. I find it odd so that "as" is used in the
reverse order compared to current use.
The use of "as" is based on an idea of mine. C# for example has "=>"
and Oxygene has "->" which I didn't consider much Pascal like. Also
the compiler needs to know the type of the lambda so it can correctly
typecheck its code (after all we have no type inference (yet :P )). So
"lambda PROCVARTYPE as EXPR/STMT" came as the most "natural" and
Pascal like variant.
First: Stressing out: I don't like it. But if we must have one, the
lambda approach is the best one yet.
Reason: At least the type is declared at a pascal-like location.
I did not note at first, but the al leaves the "Result" away. So X+5
now looks like a statement.
What would happen with
ATree.VisitPreorder(lambda TVisitor as begin X := min(10,x); X + 5; end);
Reminds me of perl: the last value is the return value.
If you look for the most natural, pascal like (ignoring the part that declaring
a function inline, IMHO is not that)
ATree.VisitPreorder(TVisitor(Result := X + 5);
ATree.VisitPreorder(TVisitor(begin Result := X + 5; end);
You are type casting the code, into a procedure of the given type.
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