[fpc-pascal] New feature: IfThen() intrinsic

[Michael Van Canneyt]

On Tue, 2 Feb 2016, Henry Vermaak wrote:

> On Tue, Feb 02, 2016 at 11:24:57AM +0100, Michael Van Canneyt wrote:
>> On Tue, 2 Feb 2016, Henry Vermaak wrote:
>>
>>> On Tue, Feb 02, 2016 at 10:49:03AM +0100, Michael Van Canneyt wrote:
>>>> So the iif in either functional or expression form has my vote.
>>>
>>> I'm surprised that you support iif in function call form.  Making
>>> something that looks like a function call but may not behave as a
>>> function call (short cut eval) seems like a recipe for disaster.
>>
>> Would you mind explaining why ?
>
> When you call a function all the arguments get evaluated before the
> function gets called.  iif will look exactly like a function call, but
> all the arguments may not be evaluated (that's the point, right).  This
> is inconsistent and ambiguous, two things that pascal tries to eschew.
>
> Even worse is that it's not a reserved symbol, so it can still be
> overridden.  A call to iif in one unit may evaluate all its arguments,
> while it may not in another unit.
>
> Pascal is not a language full of programmer traps, let's try not to add
> any!

Well, see my reply about 'robust' code for an observation about these details.

Michael.