Re^2: make subroutine that takes expression as implicit block as first arg

That won't work, for the proposed case:

Type of arg 1 to main::mygrep must be block or sub {} (not numeric eq 
+(==)) at /tmp/mygrep line 7, near "10)"
Execution of /tmp/mygrep aborted due to compilation errors.
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Perhaps something like this?

sub mygrep { my $s = "grep $_[0]"; eval $s; }

print for mygrep('$_ % 2 == 0, 0..10');    # :-)
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--
"Language shapes the way we think, and determines what we can think about."
-- B. L. Whorf

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Re^3: make subroutine that takes expression as implicit block as first arg by kennethk (Abbot) on Aug 13, 2010 at 20:01 UTC
I added a use case, as this sort of structure is a bit sensitive - perl apparently interprets the OP proposed use case as an anonymous hash because parentheses are present. When I was going through a clever phase, I played a bit with prototypes, and decided they are generally more trouble than they are worth. IMHO, of course.	[reply]