Whitespace is irrelevant p r i n t "Hello, world"; doesn't print "Hello, world" though, so you can't just put whitespace anywhere.
Also $x = "Hello"; print "$ x" will print "Hello" but @x = "Hello"; print "@ x" will print "@ x", and @$ x, $# x and $ #x are all syntax errors unless you remove the spaces.
#Edited: added those examples
use feature 'say';
our $x = "Hello";
our @y = "Hi";
our $z = ["Bonjour"];
while (<DATA>)
{
chomp;
print "$_ \t";
no warnings;
eval "$_; 1" or say $@ =~ tr/\n/ /r;
}
__DATA__
say "$x";
say "$ x";
say "@y";
say "@ y";
say @ y;
say $#y;
say $# y;
say $ #y;
say @ $z;
say @$ z;
say "$x"; Hello
say "$ x"; Hello
say "@y"; Hi
say "@ y"; @ y
say @ y; Hi
say $#y; 0
say $# y; syntax error at (eval 6) line 2, at EOF (Might be a
+runaway multi-line ;; string starting on line 1)
say $ #y; syntax error at (eval 7) line 1, at EOF
say @ $z; Bonjour
say @$ z; syntax error at (eval 9) line 1, near "@$ z"
If you [...] insert [...] white spaces between sigils and identifiers, you are somehow shooting on your own feet.
If you do it on purpose yes, but it's pretty easy to do it by mistake, either because of a typo, or because you expected spaces to be relevant inside a string, or even in some cases without noticing what's wrong, and perl may not warn you:
use v5.14;
use strict;
use warnings;
use constant MASK => 0xF0;
use constant VAL => 0x0F;
sub get_val1 { VAL }
sub get_val2() { VAL }
sub get_mask { MASK }
# Is & a function sigil or the bitwise and?
say VAL & get_mask;
say get_val1 & get_mask;
say get_val1 & MASK;
say get_val2 & MASK;
say get_val1() & MASK;
0
15
15
0
0
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