 Switch off our die/warn handlers so we don't wind up in our own
    # traps.
    $SIG{__DIE__} = $SIG{__WARN__} = '';

    $exception =~ s/\n(?=.)/\n\t/gas;

    die Carp::longmess("__diagnostics__")
	  =~ s/^__diagnostics__.*?line \d+\.?\n/
		  "Uncaught exception from user code:\n\t$exception"
	      /re;
	# up we go; where we stop, nobody knows, but i think we die now
	# but i'm deeply afraid of the &$olddie guy reraising and us getting
	# into an indirect recursion loop
};

my %exact_duplicate;
my %old_diag;
my $count;
my $wantspace;
sub splainthis {
  return 0 if $TRACEONLY;
  for (my $tmp = shift) {
    local $\;
    local $!;
    ### &finish_compilation unless %msg;
    s/(\.\s*)?\n+$//;
    my $orig = $_;
    # return unless defined;

    # get rid of the where-are-we-in-input part
    s/, <.*?> (?:line|chunk).*$//;

    # Discard 1st " at <file> line <no>" and all text beyond
    # but be aware of messages containing " at this-or-that"
    my $real = 0;
    my @secs = split( / at / );
    return unless @secs;
    $_ = $secs[0];
    for my $i ( 1..$#secs ){
        if( $secs[$i] =~ /.+? (?:line|chunk) \d+/ ){
            $real = 1;
            last;
        } else {
            $_ .= ' at ' . $secs[$i];
	}
    }

    # remove parenthesis occurring at the end of some messages 
    s/^\((.*)\)$/$1/;

    if ($exact_duplicate{$orig}++) {
	return &transmo;
    } else {
	return 0 unless &transmo;
    }

    my $short = shorten($orig);
    if ($old_diag{$_}) {
	autodescribe();
	print THITHER "$short (#$old_diag{$_})\n";
	$wantspace = 1;
    } elsif (!$msg{$_} && $orig =~ /\n./s) {
	# A multiline message, like "Attempt to reload /
	# Compilation failed"
	my $found;
	for (split /^/, $orig) {
	    splainthis($_) and $found = 1;
	}
	return $found;
    } else {
	autodescribe();
	$old_diag{$_} = ++$count;
	print THITHER "\n" if $wantspace;
	$wantspace = 0;
	print THITHER "$short (#$old_diag{$_})\n";
	if ($msg{$_}) {
	    print THITHER $msg{$_};
	} else {
	    if (0 and $standalone) { 
		print THITHER "    **** Error #$old_diag{$_} ",
			($real ? "is" : "appears to be"),
			" an unknown diagnostic message.\n\n";
	    }
	    return 0;
	} 
    }
    return 1;
  }
} 

sub autodescribe {
    if ($VERBOSE and not $count) {
	print THITHER &{$PRETTY ? \&bold : \&noop}("DESCRIPTION OF DIAGNOSTICS"),
		"\n$msg{DESCRIPTION}\n";
    } 
} 

sub unescape { 
    s {
            E<  
            ( [A-Za-z]+ )       
            >   
    } { 
         do {   
             exists $HTML_Escapes{$1}
                ? do { $HTML_Escapes{$1} }
                : do {
                    warn "Unknown escape: E<$1> in $_";
                    "E<$1>";
                } 
         } 
    }egx;
}

sub shorten {
    my $line = $_[0];
    if (length($line) > 79 and index($line, "\n") == -1) {
	my $space_place = rindex($line, ' ', 79);
	if ($space_place != -1) {
	    substr($line, $space_place, 1) = "\n\t";
	} 
    } 
    return $line;
} 


1 unless $standalone;  # or it'll complain about itself
__END__ # wish diag dbase were more accessible
