SGMLS::Refs - Forward reference handling
Contents
Description
This library can be used together with the SGMLS package to keep track of forward references from one run
to another, like the LaTeX ".aux" files. Each reference manager is an object which reads and then
rewrites a file of perl source, with the file name provided by the caller.
Example:
# Start up the reference manager before the parse.
sgml('start', sub { $refs = new SGMLS::Refs("foo.refs"); });
# Warn about any changed references at the end.
sgml('end', sub { $refs->warn; });
# Look up the title from the last parse, if available.
sgml('<div>', sub {
my $element = shift;
my $id = $element->attribute(ID)->value;
my $title = $refs->get("title:$id") || "[no title available]";
$current_div_id = $id;
output "\\section{$title}\n\n";
});
# Save the title for the next parse.
sgml('<head>', sub { push_output('string'); });
sgml('</head>', sub {
my $title = pop_output();
my $id = $current_div_id;
$refs->put("title:$id",$title);
});
Name
SGMLS::Refs - Forward reference handling
See Also:
SGMLS, SGMLS::Output.
perl v5.36.0 2022-10-13 Refs(3pm)
Synopsis
use SGMLS::Refs;
To create a new reference-manager object using the file "foo.refs":
my $refs = new SGMLS::Refs("foo.refs");
To create a new reference-manager object using the file "foo.refs" and logging changes to the file
"foo.log":
my $refs = new SGMLS::Refs("foo.refs","foo.log");
To record a reference:
$refs->put("document title",$title);
To retrieve a reference:
$title = $refs->get("document title");
To return the number of references changed since the last run:
$num = $refs->changed;
To print a LaTeX-like warning if any references have changed:
$refs->warn;
