Re: guile scheme tutorial

[amirouche@hyper.dev]

On 2019-05-07 04:15, rendaw wrote:
> On 5/4/19 8:02 PM, amirouche@hyper.dev wrote:
>> On 2019-05-04 08:08, rendaw wrote:
>>> On 5/3/19 9:45 PM, amirouche@hyper.dev wrote:
>>>> Hello!
>>>> 
>>>> 
>>> (Whoops, replied with the wrong account.)
>>> 
>>> Oh, this is great!  I've actually been putting together a small Guix
>>> guide here:
>>> https://gitlab.com/rendaw/blog/blob/master/how_to_guix_for_those_who_dont.md
>>> 
>>> 
>>> It has a small Guile primer, but it doesn't go into depth or have any
>>> hands on examples like yours.  My goal was to cover just enough so 
>>> that
>>> people could understand Guix configs (or at least 90% of them), so no
>>> recursion, etc.  I'm glad you got into records, I just kind of 
>>> handwaved
>>> that away ("they're functions", not 100% sure this is correct 
>>> either).
>> 
>> That is good. The beginning looks like guix is not worthwhile and then
>> you continue in the second page with an introduction to guile and 
>> guix.
>> I find it nice actually.
>> 
>> I spotted a minor error:
>> 
>>   (system* (string-append #$openssl "/bin/openssl")
>>            "genrsa" "-out" private-key "2048"))
>> 
>>  
>> https://gitlab.com/rendaw/blog/blob/master/how_to_guix_for_those_who_dont.md#running-executables
>> 
>> Indeed you can run programs like that but in guix it is preferred to 
>> run
>> with invoke, see the source :)
>> 
>> Thanks for sharing!
> 
> Oh awesome, thanks!  I saw the recommendation to use invoke (in the
> package guide?) but actually I'd like to know what the difference
> between invoke and system* are... the code above was something I 
> grabbed
> from the Guix source somewhere (cups.scm?)
> 
> I just checked now (defined in guix/build/utils.scm) and it looks like
> invoke raises an exception if the command has a non-zero exit, but
> otherwise they're the same.

Also it returns #t which is expected in every phase procedure.