Re: [Chicken-users] sequences egg

[Thomas Chust]

2010/11/18 Felix <address@hidden>:
> [...]
> I've put together a little library of generic "sequence" operations,
> and would like to get some feedback, since I'm not sure about the
> nomenclature and API.
> [...]

Hello,

in my opinion this library is a good idea. A feature I would like to see in this
kind of library would be some comprehension mechanism (similar to SRFI-42 or
Racket's for comprehensions).

I also noticed that iterator operations are apparently broken when the iterator
is based on a list:

        $ csi
        
        CHICKEN
        (c)2008-2010 The Chicken Team
        (c)2000-2007 Felix L. Winkelmann
        Version 4.6.3
        linux-unix-gnu-x86 [ manyargs dload ptables ]
        compiled 2010-11-12 on kali (Linux)
        
        ; [... *snip* loading modules ...]
        #;1> (use sequences)
        ; [... *snip* loading modules ...]
        #;2> (define l '(foo bar baz))
        #;3> (define i (iterator l))
        #;4> (elt l i)
        
        Error: (elt0-generic) argument mismatch - was given `((foo bar baz)
#<iterator>)' but expected: ((elt0-generic<<list>-<fixnum>> <list>
<fixnum>) (elt0-generic<<vector>-<fixnum>> <vector> <fixnum>)
(elt0-generic<<vector>-<random-access-iterator>> <vector>
<random-access-iterator>) (elt0-generic<<string>-<fixnum>> <string>
<fixnum>) (elt0-generic<<string>-<random-access-iterator>> <string>
<random-access-iterator>)
(elt0-generic<<linear-sequence>-<linear-iterator>> <linear-sequence>
<linear-iterator>) (elt0-generic<<linear-sequence>-<fixnum>>
<linear-sequence> <fixnum>)
(elt0-generic<<random-access-sequence>-<random-access-iterator>>
<random-access-sequence> <random-access-iterator>)
(elt0-generic<<random-access-sequence>-<fixnum>>
<random-access-sequence> <fixnum>))
        
                Call history:
        
                <syntax>          (elt l i)
                <eval>    (elt l i)     <--
        #;4> (advance i)
        
        Error: bad argument type - not a structure of the required type
        (foo bar baz)
        linear-sequence
        
                Call history:
        
                <syntax>          (advance i)
                <eval>    (advance i)   <--

Ciao,
Thomas


-- 
When C++ is your hammer, every problem looks like your thumb.