Hello everyone. I am often annoyed that this code:

#!/usr/bin/perl
print "Line [ ", __LINE__, " ] looks very nice\n";
print "Line [ __LINE__ ] is taken as a string-literal\n";
#print "Line [ @{[__LINE__}] is a syntax error\n";

produces this result:

Line [ 2 ] looks very nice.
Line [ __LINE__ ] is taken as a string-literal.

I would much prefer the syntax of Line 3, or some convenient token such as $LINE (or $__LINE__ or whatever I can just embed in double-quotes). Line 5 is still a lot of fanning-about, but it doesn't even compile.

The syntax of Line 2 works OK, but it is a lot of fanning-about that often makes me reluctant to include this useful bit of debugging information.

Is there a better way to include the __LINE__ information without all this fanning-about?

Thanks for reading.

- David

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David Filmer <davidfilmer@gmail.com> writes:

Hello everyone. I am often annoyed that this code:

#!/usr/bin/perl
print "Line [ ", __LINE__, " ] looks very nice\n";
print "Line [ __LINE__ ] is taken as a string-literal\n";
#print "Line [ @{[__LINE__}] is a syntax error\n";

produces this result:

Line [ 2 ] looks very nice.
Line [ __LINE__ ] is taken as a string-literal.

I would much prefer the syntax of Line 3, or some convenient token
such as $LINE (or $__LINE__ or whatever I can just embed in
double-quotes).

__LINE__ is not a Perl variable. It's just a special token replaced at
compile time by the current source line number.

Line 5 is still a lot of fanning-about, but it doesn't even compile.

s/5/3/

That line has mismatched brackets, but it wouldn't work anyway because
__LINE__ is not a variable.

The syntax of Line 2 works OK, but it is a lot of fanning-about that
often makes me reluctant to include this useful bit of debugging
information.

Is ", and he then ," really a lot of fanning about? Anyway, I don't
know of any alternative, so you'll have to decide it it's worth it.

--
Ben.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 7/03/2021 6:00 pm, David Filmer wrote:

Hello everyone. I am often annoyed that this code:

#!/usr/bin/perl
print "Line [ ", __LINE__, " ] looks very nice\n";
print "Line [ __LINE__ ] is taken as a string-literal\n";
#print "Line [ @{[__LINE__}] is a syntax error\n";

produces this result:

Line [ 2 ] looks very nice.
Line [ __LINE__ ] is taken as a string-literal.

I would much prefer the syntax of Line 3, or some convenient token such as $LINE (or $__LINE__ or whatever I can just embed in double-quotes). Line 5 is still a lot of fanning-about, but it doesn't even compile.

The syntax of Line 2 works OK, but it is a lot of fanning-about that often makes me reluctant to include this useful bit of debugging information.

Is there a better way to include the __LINE__ information without all this fanning-about?

Thanks for reading.

- David

FWIW, I would use printf:

21:29 >perl -wE "printf qq{Line [ %s ] looks nice too\n}, __LINE__;"
Line [ 1 ] looks nice too

21:30 >

Hope that helps,

--
Athanasius <°(((><

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