gobo-eiffel-develop

[gobo-eiffel-develop] Postcondition failure in {DS_HASH_TABLE}.search_position

[Colin P. A. <co...@co...>]

Hello Eric,

While testing gexslt, I've come across a postcondition violation in
this routine. I tried debugging it, but I couldn't work out why the
problem was occurring.

So I've checked in the code, hoping that you can work out what is
wrong.

The following command line will reproduce the problem:

gexslt group021.xsl group021.xml

I will send the two xml files needed for this to you by private email,
as they are from the W3C suite, and so I should not post them on a
public mailing list.
-- 
Colin Adams
Preston Lancashire

Re: [gobo-eiffel-develop] Postcondition failure in {DS_HASH_TABLE}.search_position

[Eric B. <er...@go...>]

Colin Paul Adams wrote:
> While testing gexslt, I've come across a postcondition violation in
> this routine. I tried debugging it, but I couldn't work out why the
> problem was occurring.

There are two reasons why you could get a postcondition violation
in this routine. Either this routine (or its postcondition) has a
bug, or your hash table contains mutable keys whose comparison
criterion or hash code has changed since it was first inserted.

> So I've checked in the code, hoping that you can work out what is
> wrong.
> 
> The following command line will reproduce the problem:
> 
> gexslt group021.xsl group021.xml

OK, I will have a look.

-- 
Eric Bezault
mailto:er...@go...
http://www.gobosoft.com

Re: [gobo-eiffel-develop] Postcondition failure in {DS_HASH_TABLE}.search_position

[Colin P. A. <co...@co...>]

>>>>> "Eric" == Eric Bezault <er...@go...> writes:

    Eric> There are two reasons why you could get a postcondition
    Eric> violation in this routine. Either this routine (or its
    Eric> postcondition) has a bug, or your hash table contains
    Eric> mutable keys whose comparison criterion or hash code has
    Eric> changed since it was first inserted.

I've thought of another possibility.
The items are datetimes in different time zones.
It may be that I have two items that compare equal, but their hash
codes are not equal.

I'll check on this tomorrow.
-- 
Colin Adams
Preston Lancashire

Re: [gobo-eiffel-develop] Postcondition failure in {DS_HASH_TABLE}.search_position

[Colin P. A. <co...@co...>]

>>>>> "Colin" == Colin Paul Adams <co...@co...> writes:

>>>>> "Eric" == Eric Bezault <er...@go...> writes:
    Eric> There are two reasons why you could get a postcondition
    Eric> violation in this routine. Either this routine (or its
    Eric> postcondition) has a bug, or your hash table contains
    Eric> mutable keys whose comparison criterion or hash code has
    Eric> changed since it was first inserted.

    Colin> I've thought of another possibility.  The items are
    Colin> datetimes in different time zones.  It may be that I have
    Colin> two items that compare equal, but their hash codes are not
    Colin> equal.

Yes that was the problem. 
I had actually thought about it, it seems, but just got it wrong.

Fixed now.
-- 
Colin Adams
Preston Lancashire