Re: map syntax bug-a-boo?

[dvergin]

Now, brethren and sistern, let's all charitabley agree to stipulate that the horrid "map in a void context" was merely for the purpose of reducing the problem to its bare essentials.

It would appear that, because of what you have put inside the {...}, Perl is taking that to be an expression and thus needing a comma after it.

use strict;
my @l = 1..10;
map { 1, 2 }, @l;
map { "$_", 2 }, @l;

does not produce errors. And if you say:

print map { 1, 2 }, @l;
print map { "$_", 2 }, @l;

you will see a bunch of hash-refs. So Perl is seeing {1,2} as an anonymous hash rather than as a BLOCK that happens to return something. (A very reasonable reading now that we look at it that way.)

------------------------------------------------------------
"Perl is a mess and that's good because the
problem space is also a mess." - Larry Wall

[MeowChow]

I was thinking along the same lines, but the fact that the following does work seems to contradict this argument, or at least imply that it's not the whole story:

map { $_, 2 } @l;

Though, now that I think about it, all this probably reflects a perl heuristic/optimization in the parser which says something along the lines of "if, within the bracketed expression, I see a constant and then a comma, I'm going to assume the expression is a hash, and not a block, no matter what comes afterwards...."

   MeowChow                                   
               s aamecha.s a..a\u$&owag.print