[Jprogramming] Parsing {{ }}

['Mike Day' via Programming]

Oh well.  I thought you might have test-bedded these forms in J before moving to C, Henry, in which case there might have been a readymade J script!

As for Raul’s suggestion,  that’s fine,  but, in as far as I have copied across to J701,  just typing the verb’s name in the session reveals the n : 0 ... ) form.  Essentially,  this leads to amending the J903 script,  which rather defeats the purpose.  I haven’t use nested ddefs.

Anyway,  I’ve got a little way into writing a basic parser which will suffice.

Thanks,

Mike

Sent from my iPad

> On 11 Jan 2022, at 14:42, Henry Rich <henryhrich at gmail.com> wrote:
> 
> There is nothing I know of that does what {{ }} does.  But Raul's idea is pretty close.  As he notes, it fails for nested {{ }} (there is much code that expects the result of 5!:5 <'explicitname' to have the form m : string, but nested {{ }} seemed OK).
> 
> Henry Rich
> 
>> On 1/11/2022 9:19 AM, Raul Miller wrote:
>> If you avoid nested {{ }} blocks, 5!:5 would do this.
>> 
>> In other words, this works:
>> 
>>    mean=: {{ (+/ % #) y}}
>>    5!:5<'mean'
>> 3 : '(+/ % #) y'
>> 
>> But this would be useless for your purposes:
>> 
>>    mean=: {{ {{x + y}} {{u/}} {{x % y}} {{#y}} }}
>>    5!:5<'mean'
>> 3 : '{{ x + y }}  {{ u/ }}  {{ x % y }}  {{ #y }}  '
>> 
>> FYI,
>> 
>> 
>> --
>> Raul
>> 
>> On Tue, Jan 11, 2022 at 4:25 AM 'Mike Day' via Programming
>> <programming at jsoftware.com> wrote:
>>> For Henry I expect: as I share code between J903 on the laptop and J701 on this iPad,  I’ve been avoiding the use of {{ }} objects.  (My iPad can’t support Ian’s new J902.)
>>> 
>>> But I was just wondering about adding a routine to the J701 start.ijs script to parse a J903 script translating direct definitions to their earlier equivalents.  And then I thought there might already be native J code to do this.
>>> 
>>> So: do I need to invent this wheel?
>>> 
>>> Thanks,
>>> 
>>> Mike
>>> 
>>> Sent from my iPad
>>> ----------------------------------------------------------------------
>>> For information about J forums see http://www.jsoftware.com/forums.htm
>> ----------------------------------------------------------------------
>> For information about J forums see http://www.jsoftware.com/forums.htm
> 
> 
> -- 
> This email has been checked for viruses by AVG.
> https://www.avg.com
> 
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm