Re^2: why avoid & on function call

The placement of a sub is important ~~only~~mainly when you call it without parentheses, i.e. as a bareword. When such a call is being parsed, the subs already parsed are recognised and the bareword is parsed as their call, otherwise without strict, the bareword is stringified, and with strict, you get an error.

#!/usr/bin/perl
use warnings;

print "", frob();  # 12
print "", frob;    # frob

use strict;

print "", frob();  # 12
# print "", frob;

sub frob {
    12
}
[download]

Uncommenting the last last print line would make the source unparsable with

Bareword "frob" not allwoed while "strict subs" in use
[download]

Updated: as shown in the text, thanks kcott.

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

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Re^3: why avoid & on function call by kcott (Archbishop) on Dec 27, 2020 at 19:14 UTC
"The placement of a sub is important only when you call it without parentheses, ..." I disagree with the inclusion of the word only in that statement. Here's a situation where placement is important when parentheses are used: `$ perl -wE ' sub meaning () { 42 } say meaning(); ' 42` [download] `$ perl -wE ' say meaning(); sub meaning () { 42 } ' main::meaning() called too early to check prototype at -e line 2. 42` [download] You can, of course, predeclare and leave the definition for later: `$ perl -wE ' sub meaning (); say meaning(); # ... later in code with other subroutine defintions sub meaning () { 42 } ' 42` [download] — Ken	[reply] [d/l] [select]
Re^3: why avoid & on function call by LanX (Saint) on Dec 27, 2020 at 17:59 UTC
Bareword use without parens is also the reason why the `sub NAME;` syntax without function `{BODY}` exists. One can pre-declare functions for the first parse, which are later defined (or resolved via AUTOLOAD) `DB<188> sub frob; frob(1,2,3); sub frob { say "@_" } 1 2 3 DB<189>` [download] Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply] [d/l] [select]