Re: Internal visibility

[Clinton Ebadi <clinton@unknownlamer.org>]

Han-Wen Nienhuys <hanwen@xs4all.nl> writes:

> Ludovic Courtès escreveu:
>>>> Guile's string API is aiming not to be 8-bit-assuming, and I would
>>>> guess from the code above that the C++ string class is 8-bit-assuming.
>>> Sorry, I guess I don't understand. What _is_the assumption for
>>> representing strings in GUILE?
>> 
>> Strings in Guile will eventually be sequences of Unicode code points (as
>> opposed to "bytes"), which can be represented in a variety of different
>> ways (UTF-8, UCS-4, etc.).  How Guile represents strings and whether
>> this representation "changes dynamically" (as you suggested) should not
>> be exposed to the applications in order to leave as much freedom as
>> possible to Guile's implementation strategy.
>
> I think that a sequence of Unicode code points this is a somewhat
> limited view of how strings should be used.  Among others, the
> implication is that programs cannot rely on being able to index a
> string in O(1) time (since the string might be UTF-x encoded).
>
> What do I use if I want to have guaranteed O(1) indexing -that is- if
> I want to manipulate strings of bytes?  
>
> How would I read the contents of a binary file without jumping through 
> encoding hoops?

Uniform byte vectors. If you're using C you can just read everything
into a normal C array and then use
scm_take_u8_vector()/scm_u8vector_elements().

-- 
thehurdguy: LOL you'll end up being like that urban myth
thehurdguy: the guy that thinks he's orange juice
thehurdguy: I'll be like "dude, I know a lisp programmer who did
            so much acid, he thinks he's an empty list..."