Hi,
(sorry for yet another p6l email mentioning junctions; if they annoy you
just ignore this mail :-)
while reviewing some tests I found the "each() comprehension" in S02
that evaded my attention so far.
Do we really want to keep such a rather obscure syntactic
transformation? I find an explicit grep much more readable; if we want
it to work in a more general case, it might become some kind of junction
that, on autothreading, keeps a mapping between the original item and
the new value, and on collapse returns all items for which the new value
is true. Something along these lines:
g(f(each(1..3))9
becomes
g(each(1 => f(1), 2 => f(2), 3 => f(3)))
becomes
each(1 => g(f(1)), 2 => g(f(2)), 3 => (g(f(3)))
and on collapse returns
1..3.grep:{g(f($_))};
IMHO this would DWIM more in arbitrary code than the special syntactic
form envisioned
Also this part of S02 is rather obscure, IMHO:
> In particular,
>
> @result = each(@x) ~~ {...};
>
> is equivalent to
>
> @result = @x.grep:{...};
Should it be @result = @x.grep:{ $_ ~~ ... } instead? Otherwise
'each(@x) ~~ 1..3' would be transformed into '@x.grep:{1..3}', which
would return the full list. (Or do adverbial blocks some magic smart
matching that I'm not aware of?)
Cheers,
Moritz
