Which hashtable API to use?

Which hashtable API to use?

[Alexandru Cojocaru]

Hi,
currently there are three hashtable APIs: R6RS, SRFI-69 and Guile's one.
Which one to choose?

Also what's exactly the difference between hash, hashq and hashv?

Best regards,
Alexandru Cojocaru

Re: Which hashtable API to use?

[Matt Wette]

WIth respect to your second question: hash table operations can compare keys with equal?, eq?, or eqv?.
Which one do you want to use?

On Aug 16, 2013, at 4:38 AM, Alexandru Cojocaru wrote:

> Hi,
> currently there are three hashtable APIs: R6RS, SRFI-69 and Guile's one.
> Which one to choose?
> 
> Also what's exactly the difference between hash, hashq and hashv?
> 
> Best regards,
> Alexandru Cojocaru
> 

Re: Which hashtable API to use?

[Alexandru Cojocaru]

Ok, I got it. Basicaly if I do `(hash '(a) 3)' I'll always get the same 
hash because it uses the contents of the list,
while if I do `(hashq '(a) 3)' I may get different hashes because it 
uses the list's pointer address.

On 16.08.2013 14:47, Matt Wette wrote:
> WIth respect to your second question: hash table operations can compare keys with equal?, eq?, or eqv?.
> Which one do you want to use?
>
> On Aug 16, 2013, at 4:38 AM, Alexandru Cojocaru wrote:
>
>> Hi,
>> currently there are three hashtable APIs: R6RS, SRFI-69 and Guile's one.
>> Which one to choose?
>>
>> Also what's exactly the difference between hash, hashq and hashv?
>>
>> Best regards,
>> Alexandru Cojocaru
>>

Re: Which hashtable API to use?

[Matt Wette]

guile> (define ht (make-hash-table 7))
guile> (hash-set! ht "matt" "awesome")
"awesome"
guile> (hashq-ref ht "matt")
#f
guile> (hash-ref ht "matt")
"awesome"

On Aug 16, 2013, at 6:33 AM, Alexandru Cojocaru wrote:

> Ok, I got it. Basicaly if I do `(hash '(a) 3)' I'll always get the same hash because it uses the contents of the list,
> while if I do `(hashq '(a) 3)' I may get different hashes because it uses the list's pointer address.
> 
> On 16.08.2013 14:47, Matt Wette wrote:
>> WIth respect to your second question: hash table operations can compare keys with equal?, eq?, or eqv?.
>> Which one do you want to use?
>> 
>> On Aug 16, 2013, at 4:38 AM, Alexandru Cojocaru wrote:
>> 
>>> Hi,
>>> currently there are three hashtable APIs: R6RS, SRFI-69 and Guile's one.
>>> Which one to choose?
>>> 
>>> Also what's exactly the difference between hash, hashq and hashv?
>>> 
>>> Best regards,
>>> Alexandru Cojocaru
>>> 
> 

Re: Which hashtable API to use?

[Thien-Thi Nguyen]

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() Alexandru Cojocaru <xojoc@gmx.com>
() Fri, 16 Aug 2013 13:38:38 +0200

   currently there are three hashtable APIs [...]
   Which one to choose?

It's best to choose what you feel comfortable maintaining.
It's next best to choose what you can write and understand.
After that is cut and paste copying from other people's code.
Worst is abiding blindly by advice in a j.r.hacker posting...

-- 
Thien-Thi Nguyen
   GPG key: 4C807502
   (if you're human and you know it)
      read my lisp: (responsep (questions 'technical)
                               (not (via 'mailing-list)))
                     => nil

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