[Gretl-devel] Re: built-in strings: $ vs. @
On Wed, 1 Jul 2020, Sven Schreiber wrote:
Am 29.06.20 um 16:49 schrieb Allin Cottrell:
> On Mon, 29 Jun 2020, Sven Schreiber wrote:
>
>> ? eval @gretldir
>>> C:
>> Das Symbol 'C' ist nicht definiert # [undefined]
>> ? eval $gretldir
>> C:\Program Files\gretl
>> ?
>>
>> I would have expected @gretldir to either work, or to return an empty
>> string, or to throw an error, but not this problem. Maybe some backslash
>> trouble?
>
> Actually the first result should be expected. "@" does string
> substitution, and after substiitution has been done the input line
> line reads
>
> eval C:\Program Files\gretl
>
> To get the effect you apparently expected you'd need to do
>
> eval "@gretldir"
I guess you're right!
In some contexts one ends up thinking, "Why doesn't @-substitution
put the replacement in quotes?" But of course that would render such
substitution useless for its primary purpose.
Allin