Re: map syntax error -- weird

[LanX]

IMHO the parser is confused if or if not you mean to pass an anonymous hash instead of a code block to map.

Put the list into parens

  DB<105>  map { ( "x" => $_ ) } qw(1 2 3); 
 => ("x", 1, "x", 2, "x", 3)

  DB<106>  map { ( "x" => $y ) } qw(1 2 3); 
 => ("x", undef, "x", undef, "x", undef)

  DB<110> @opts = map { ( "$_=s" => \$opt{$_} ) } @vals;
 => ("title=s", \undef, "artist=s", \undef, "album=s", \undef)

[McA]

Rolf was faster with his answer than me. Allow one annotation: perldoc -f map has a paragraph explaining this ambiguity.

McA

[LanX]

oops true! =)

 
               "{" starts both hash references and blocks, so "map { ..."
               could be either the start of map BLOCK LIST or map EXPR, LIST.
               Because perl doesn’t look ahead for the closing "}" it has to
               take a guess at which its dealing with based what it finds just
               after the "{". Usually it gets it right, but if it doesn’t it
               won’t realize something is wrong until it gets to the "}" and
               encounters the missing (or unexpected) comma. The syntax error
               will be reported close to the "}" but you’ll need to change
               something near the "{" such as using a unary "+" to give perl
               some help:

Since PBP "map EXPR, LIST" fell completely out of my scope, but it explains why a hash-ref could even be considered valid here.