Re: Hash table read syntax in guile 2.0

[Hengqing Hu]

Thanks for the collaboration.

You are right, that's what I mean by a deep list.

One usage of knowing the information is to tell
whether the hash table is empty or not,
Since a hash-empty? procedure is not provided.

在 2013-2-18，10:01，Daniel Hartwig <address@hidden> 写道：

> On 17 February 2013 22:15, Hengqing Hu <address@hidden> wrote:
>> I don't know it's intentional or a bug,
>> but now object->string returns something different.
> 
> It was an intentional change.  Previously you could not tell apart two
> distinct hash tables that happened to have the same number of elements
> and bucket size.  Now you can, because the output includes an unique
> object id.
> 
>> 
>> My understanding of length and fold is the same for deep lists as for
>> hash table.
> 
> Interesting.  By deep list do you mean a list that has lists as it's
> elements, like:
> 
>  (define x '((1 2 3) (4 5 6)))
> 
> or ..?
> 
>> 
>> It's great you have provided a patch so a constant time way
>> to know no of key/value bindings in a hash table could be more accessible..
> 
> Its not an operation fundamental to hash-tables (indeed, some
> implementations can not determine this in constant time), and I think
> that is the main reason for its absence.  What do you use the
> information for?
> 
> Regards