Re: Different higher-order func notation? (was Re: RFC 23 (v1) Higher order functions)

[Jeremy Howard]

John Porter wrote:
> Has anyone suggested '*'?  Since its use for typeglobs is (repsumably)
> going away, it's available (right?).
>
> It the "wildcard" mnemonic value is consistent with "placeholder".
>
Yes, it's been suggested, but we might be too late on that one--another RFC
suggests reserving '*' for reserved perl identifiers.

Maybe we don't have to resolve this in the RFC--since the choice of prefix
depends on a number of other design decisions. Could we use one consistant
prefix in the examples, and point out in the implementation that other
prefixes are possible. eg:
- ^: Our preferred option, but need to ensure that ambiguity in regexps is
avoided
- *: Next best, if not used to signify perl reserved identifiers
- _: Next best option

Is the regexp issue the only problem for '^'? If so, isn't this an issue for
any prefix? Presumably the placeholder identifier should be 'special' under
the same conditions as '$', when in a regexp...