Extend handling for \let a bit, to also allow \let\something=<character>. We

still don't support things like \let^^M=\something, where ^^M could actually be
any active character.  Print a decent warning if we find one we can't handle.

Doc/perl/python.perl

@@ -63,12 +63,23 @@ sub ArabictoRoman {
 sub do_cmd_let{
     local($_) = @_;
     my $matched = 0;
-    s/\s*[\\]([a-zA-Z]+)\s*(=\s*)?[\\]([a-zA-Z]*)/$matched=1; ''/e;
+    s/[\\]([a-zA-Z]+)\s*(=\s*)?[\\]([a-zA-Z]*)/$matched=1; ''/e;
     if ($matched) {
 	my($new, $old) = ($1, $3);
 	eval "sub do_cmd_$new { do_cmd_$old" . '(@_); }';
 	print "\ndefining handler for \\$new using \\$old\n";
     }
+    else {
+	s/[\\]([a-zA-Z]+)\s*(=\s*)?([^\\])/$matched=1; ''/es;
+	if ($matched) {
+	    my($new, $char) = ($1, $3);
+	    eval "sub do_cmd_$new { \"\\$char\" . \@_[0]; }";
+	    print "\ndefining handler for \\$new to insert '$char'\n";
+	}
+	else {
+	    write_warnings("Could not interpret \\let construct...");
+	}
+    }
     $_;
 }