[fpc-devel] for-in-index loop

[Michael Van Canneyt]

On Sat, 26 Jan 2013, Paul Ishenin wrote:

> 26.01.13, 2:32, Michael Van Canneyt пишет:
>
>> Pascal is an explicitly declarative language. Anonymous functions go
>> 100% against this. It is the readability horror I associate with
>> Javascript.
>
> I wonder where you were when Operators feature has been added to pascal? Or 
> generics?

Generics was implemented without my knowledge. I only found out when suddenly
the classes unit had been changed to use them. After a horrible discussion, this 
was reversed, because of the drop in speed you got when using generics.

Operators are a natural thing:
Pascal defines some basic types and operations on them.
Pascal allows you to define extra types, so it is natural 
that it allows you to define these operations on them.

> I think now when operators for simple types are present in the language it is 
> too late to care about explicitly declarative language. It is simple not 
> explicit anymore.
>
> And index (or better to call it key) extension for for-in loop will not make 
> it less explicit for sure.

Personally, I think the tuple approach proposal is more general, and therefor better.

Once more, I do not think that language extensions are bad. 
I judge them on a case by case basis.

But if I must choose between

for a,b in c do

(with C a tuple enumerator/iterator) or

for a in c index b do

Then the former is ten times (well, a lot) better.

So if someone were to introduce that to solve the original poster's problem, 
you will not hear me protesting, it will have been well worth the energy 
I put in this discussion.

Michael.