One thing to remember is that empty is already defined as a verb
empty
(i.0 0)"_
So if you overwrite this you may break some code if you have previously relied
on the existing verb definition.
I think along the lines that Pascal mentioned that null could be similarly
defined as
null NB. check that it is not already used
|value error: null
null=:(i.0)"_
NULL NB. check that it is not already used - uppercase for global nouns is
a convention I like and is often seen in J code
|value error: NULL
NULL=:'' NB. I use this as the null string (same as what John suggested)
NULL-:null 2 NB. any argument produces NULL from null
1
Hope this helps,
Cheers, bob
> On Jun 7, 2017, at 8:09 AM, 'Jon Hough' via Programming
> <[email protected]> wrote:
>
>
> I may be wrong in doing this, but I usually write
> empty=: ''
> to signify an empty list, array, matrix etc.
>
>
> On Jun 7, 2017, 23:59, at 23:59, Michael Rice <[email protected]> wrote:
>> Is there a special "noun" for an empty list?
>>
>> Creating one seems enigmatic.
>>
>> empty =: 1 2
>> empty
>> 1 2
>> empty =: }. empty
>> empty
>> 2
>> empty =: }. empty
>> empty
>>
>> empty1 =:
>> |syntax error
>> | empty1=:
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