passing parameters in a send call.

Graham Samuel livfoss at mac.com
Mon May 22 11:00:31 EDT 2006


On Sun, 21 May 2006 15:28:28 -0600, Dar Scott <dsc at swcp.com> wrote
> On May 21, 2006, at 3:01 PM, Sarah Reichelt wrote:
>
>
>> I always use something like:
>>   send "myAdd " & pArrayA to stack "someStack"
>>
>> so that the variable is evaluated before the send.
>>
>
> Hi, Sarah!
>
> I'll pick on two aspects of that.
>
>
> First of all, I haven't been convinced that there are any merits to
> this:
>
>     send "myCmd " & x & comma & y to ...
>
> Over this:
>
>     send "myCmd x, y" to ...
>
> And it has some potential problems, such as when x contains a comma.
> (Also, the latter lends itself to some future (I hope) compiler
> optimization that compiles code that does not require runtime
> compiling.)
>
>
> Second, in this particular case where pArrayA is an array, the
> expression '"myAdd " & pArrayA' will resolve to "myAdd ".  The array
> value looks empty to '&'.

Isn't it true that

    send "myCmd x,y" to...

  just sends that exact string (minus the quotes)  to the target: if  
so, the target environment can only resolve x and y if it's in the  
same name space as the script that did the sending (I mean if it is  
able to evaluate x and y), which is in general not true (after all,  
the point of handler parameters is to pass information from one  
context to another). So if I'm right

    send "myCmd"& x &","& y to...

first evaluates x and y in the context of the sender (which is what  
Sarah said) and therefore achieves the expected result, whereas the  
other method doesn't. Arrays being a special case may not work  
anyway, but I'm trying to make a more general point.

I hope what I've just written makes sense.

Graham


----------------------------------------
Graham Samuel / The Living Fossil Co. / UK and France




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