On May 5, 2005, at 11:28 , John Williams wrote:
How does [+] know you mean
reduce &infix:<+>, @array;
instead of
reduce &prefix:<+>, @array;
which is nonsense, but the [+] is in a prefix position.
Because [] applies only to infix operators, as I understand it.
With the hyper metaoperator, the real operator is always in the place
where it would normally be parsed. But this metaoperator pulls the real
operator out of its usual pre/in/post position.
Well, if it was in its place, you wouldn't need to reduce it, would you?
I suppose users will need to know the answer when they start trying to write their own metaoperators.
They should write them only for infix operators.
I can see how to ask for a binary (hence infix) operator, but how do I ask
for a prefix or postfix operator specifically, which +<< and >>+ do?
Maybe there are Operator::Prefix, etc, roles defined so you can ask for
them?
Ask for them for what?
Regards,
David
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