On Wed, 4 May 2005, Larry Wall wrote: > It would be nice to have an easy-to-access "What's this?" interface > that could be stitched into your favorite editor to identify what's > under the cursor, or at least a command like: > > p6explain '[+]'
That would make me extremely happy. > : $sum = [+] @array; # meta operator Another random thought which came to me (right after "\\+" could be mnemonic for "return a function ref for this operator") was this: How does [+] know you mean reduce &infix:<+>, @array; instead of reduce &prefix:<+>, @array; which is nonsense, but the [+] is in a prefix position. With the hyper metaoperator, the real operator is always in the place where it would normally be parsed. But this metaoperator pulls the real operator out of its usual pre/in/post position. I suppose users will need to know the answer when they start trying to write their own metaoperators. Maybe the metaoperator's function signature resolves that somehow? But I haven't been following the function signature thread closely. I can see how to ask for a binary (hence infix) operator, but how do I ask for a prefix or postfix operator specifically, which +<< and >>+ do? Maybe there are Operator::Prefix, etc, roles defined so you can ask for them? ~ John Williams A06 typo: > infix:+( prefix:-($a), $b) > > [Update: That's now > > infix:<+>( prefix:-($a), $b) > > .] The correction only corrected one of the errors: infix:<+>( prefix:<->($a), $b)
