On May 30, 2007, at 16:38, David Nicol wrote:
We can declare a line number, in source code, like so
# perl <<foo
#line 54
die smiling
foo
smiling at - line 54.
#
and counting newlines within a Filter::Simple code block is easy
enough
but how do I find out what line to start at, so I can insert #line
comments
into my filter output that will match the input? I am about to
experiment with
caller(N) to see how many frames back to go, then I'll use that,
but I am asking
here in case anyone knows a better way.
caller() is a good solution. I use it, Filter::Util::Call, and some
involved #line magic to maintain sane line numbers in
Filter::Template. This short example defines a "whatever" template,
then expands it inline. The resulting error message follows. (Note
that #line directives seriously confuse perl -d. I half-jokingly
suggested floating-point line numbers so source filters could insert
lines 1.01 through 1.10 between lines 1 and 2 if necessary. But I
digress...)
#!/usr/bin/env perl
use Filter::Template;
template whatever (why) {
die "whatever died: ", why;
}
{% whatever "stuff" %}
__END__
whatever died: stuff at template whatever (defined in moo.perl at
line 6) invoked from moo.perl line 9.
--
Rocco Caputo - [EMAIL PROTECTED]
