Re^5: Line numbers

in reply to Re^4: Line numbers
in thread Line numbers

Right. The added complexity actually comes from introducing the say function, which takes a list.

say (caller(0))[0];
[download]

is expanding to:

say $package, $filename, $line, $subroutine, $hasargs,$wantarray, $eva
+ltext, $is_require, $hints, $bitmask, $hinthash,[0];
[download]

This gives you the syntax error:

say [0];
[download]

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Re^6: Line numbers by LanX (Saint) on Mar 17, 2012 at 02:04 UTC
> is expanding to: > `say $package, $filename, $line, $subroutine, $hasargs,$wantarray, $evaltext, $is +_require, $hints, $bitmask, $hinthash,[0];` nope, and you're showing valid code! After the last comma comes a literal arrayref `[0]`. `DB<100> print $a,[0]; ARRAY(0x84e16b8)` [download] the syntax-error comes from appending `[0]` unseparated to a function call `say()`. and nothing is "expanded" at parsing time. Cheers Rolf	[reply] [d/l] [select]
Re^7: Line numbers by gg48gg (Sexton) on Mar 19, 2012 at 17:42 UTC
Thanks for setting me straight Rolf. I was getting an error because I didn't have the say feature enabled. I guess I shouldn't have stated it so matter-of-fact. I was so sure I had it figured out. I am still a little confused about this and why anonymous' code works... `print '', (caller(0))[0];` [download] and why this gets a syntax error: `print (caller(0))[0];` [download]	[reply] [d/l] [select]
Re^8: Line numbers by LanX (Saint) on Mar 19, 2012 at 18:22 UTC
Because parens around sub-args are optional. `print '', (caller(0))[0];` means `print ( '', (caller(0))[0] );` But providing explicit parens after a sub-name will disable automatic grouping of args. Cheers Rolf	[reply] [d/l] [select]
Re^9: Line numbers by gg48gg (Sexton) on Mar 19, 2012 at 19:02 UTC
Re^6: Line numbers by Anonymous Monk on Mar 17, 2012 at 02:10 UTC
Actually, this is wrong! When you say: `print (caller(0))[0]`, print is interpretated as a function (equaivalent to `print('hi')[0]`), but it works fine if you say: `print '', (caller(0))[0]`	[reply] [d/l] [select]

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