Dave Hanson <drh@Princeton.EDU> (06/11/91)
is the outcome below a bug in STextTable?
it appears to me that STable compares keys with NIL
and that TexT.Compare no longer accepts NIL arguments
(did it ever?).
or perhaps i've made some (obvious) error in using
STexTTable?
elan 344 cat Main.m3
MODULE Main;
IMPORT STextTable;
VAR tab := STextTable.New();
count: REF INTEGER;
BEGIN
count := NEW(REF INTEGER);
count^ := 1;
EVAL STextTable.Put(tab, "foo", count)
END Main.
elan 345 m3 Main.m3 -lm3data
elan 346 a.out
M3 runtime error: Text.Compare: NIL argument
Quit (core dumped)
elan 347 kalsow (Bill Kalsow) (06/11/91)
Yes, it's a bug in STextTable. It calls Text.Compare with NIL arguments. The language report specifies that passing NIL to any procedure in the Text interface is a checked runtime error. Early releases of SRC Modula-3 didn't adhere to this piece of the specification. Version 1.6 does. We'll fix STextTable for the next release. Thanks for the bug report. - Bill Kalsow
goldberg@parc.xerox.com (David Goldberg) (06/12/91)
This bug has been addressed earlier: Date: Mon, 1 Apr 1991 18:00:12 PST From: muller@src.dec.com (Eric Muller) Subject: SRC-M3 1.6: bug in STextTable. To: modula3.parc@xerox.com Norman Ramsey and David Golberg reported that STextTable sometime fails with a runtime error in Text.Compare. The Text module now implements its interface properly, i.e. it complains when a NIL Text.T is passed to one of the Text routines. Unfortunately I failed to modify all the clients of Text so that they do not call Text.xxx with a NIL Text.T. Here is a version of STextTable.Compare that will do the right thing: PROCEDURE Compare (arg: REFANY; key1, key2: STable.Key): INTEGER = BEGIN IF key1 = NIL THEN key1 := ""; END; IF key2 = NIL THEN key2 := ""; END; RETURN Text.Compare (key1, key2) END Compare; Thanks to Norman and David for reporting this bug. -- Eric.