Good point.
That said, this version will throw an error if you use a name that
does not have a noun. But I think you could replace ".@}. with ".@}.
::] to deal with that case.
And you could use a different locale by replacing ". with do_locale_
or do__localeref
Thanks,
--
Raul
On Mon, Jul 2, 2012 at 12:10 PM, Henry Rich <henryhr...@nc.rr.com> wrote:
> Regex version:
>
> dolsub =: '\$[A-Z]*'&(".@}. rxapply)
>
> This just uses the current locale.
>
> Henry Rich
>
> On 7/2/2012 11:52 AM, Raul Miller wrote:
>> Some programming languages (unix shell, perl, php) provide a $
>> substitution mechanism where a literal string may contain embedded
>> variable references which get replaced with the value of the variable.
>>
>> This can be handy.
>>
>> Here's an example implementation of this kind of mechanism in J:
>>
>> IDCHARS=: '$ABCDEFGHIJKLMNOPQRSTUVWXYZ'
>>
>> dolsub1=: 1 :0
>> loc=. boxopen m
>> n=. y (e. i. 0:) IDCHARS
>> if. n < 3 do. <y return. end.
>> nm=. }.n{. y
>> if. 0 ~: nc__loc <nm do. <y return. end.
>> <(,":do__loc nm),n}.y
>> )
>>
>> dolsub=: 1 :0
>> 2 }. [: ; [: m dolsub1;.1 '$ ', ]
>> )
>>
>> Example, given:
>>
>> sample=:0 :0
>>
>> This is some sample text
>> Here's an example substitution:
>> ($IDCHARS)
>> )
>>
>> dolsub can replace $IDCHARS with the value defined for IDXCHARS:
>>
>> 'base' dolsub sample
>>
>> This is some sample text
>> Here's an example substitution:
>> ($ABCDEFGHIJKLMNOPQRSTUVWXYZ)
>>
>>
>> Notes:
>>
>> dolsub is an adverb. The locale used to resolve names is its left
>> argument. If you do not want the z locale to be referenced, make sure
>> it's not a part of the locale's path.
>>
>> In this implementation, I only allow names which are ALL CAPS and
>> which are at least 2 characters long. Extending this to support lower
>> case alphanumerics is trivial.
>>
>> In this implementation, I only interpolate names with noun definitions.
>>
>> I do not attempt to provide table formatting for tabular values,
>> because that gets into ambiguities I do not care about. I'm ravelling
>> so I can ignore leading 1 dimensions.
>>
>> The expression y (e. i. 0:) IDCHARS is supported by special code (but
>> that's only a minor speed improvement for this kind of routine).
>>
>> FYI,
>>
>
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
