Doc: fix remaining over-length entries in SQL keywords table.

tglsfdc · tglsfdc · commit 4d1563717fb1 · 2020-05-11T20:03:55.000-04:00
Even after the tweaking I did in commit 5545b69, some of the longer keywords mentioned in the SQL standard don't fit the available space in PDF output. I experimented with various solutions like putting such keywords on their own table lines, but everything looked ugly or confusing or both; worse, the weirdness also appeared in the HTML version, which (normally) doesn't need it. The best answer seems to be to insert &zwsp; into long keywords so that they can be broken into two lines when, and only when, needed. It doesn't look too awful if the break happens after an underscore --- and fortunately, all the problematic keywords have underscores. Discussion: https://postgr.es/m/6916.1589146280@sss.pgh.pa.us
diff --git a/doc/src/sgml/generate-keywords-table.pl b/doc/src/sgml/generate-keywords-table.pl
@@ -82,8 +82,13 @@ END
 
 foreach my $word (sort keys %keywords)
 {
+	# Insert zwsp's into very long keywords, so that they can be broken
+	# into multiple lines in PDF format (or narrow HTML windows).
+	my $printword = $word;
+	$printword =~ s/_/_&zwsp;/g if (length($printword) > 20);
+
 	print "   <row>\n";
-	print "    <entry><token>$word</token></entry>\n";
+	print "    <entry><token>$printword</token></entry>\n";
 
 	print "    <entry>";
 	if ($keywords{$word}{pg}{'unreserved'})
