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

[Michael Van Canneyt]

On Mon, 1 Feb 2016, Maciej Izak wrote:

> 2016-02-01 13:09 GMT+01:00 Michael Van Canneyt <michael at freepascal.org>:
>>
>> No. The compiler already uses &.
>>
>> & means 'the following is an identifier even if it is a keyword'.
>>
>> You can perfectly declare and compile:
>>
>> Var
>>   &if : integer;
>>
>> begin
>>   &if:=1;
>> end.
>>
>> So &if is a bad idea.
>
>
> Yes it is possible. Anyway it is better idea than IfThen. You treat facts
> selectively. How often is used &if and how often is used IfThen?

You missed my point.

>
> &IfThen looks also good (I like shorter syntax &if). With "&" prefix it is
> obvious that this function is unique.

You misunderstand.

The & character cannot be used as part of an identifier, it is a special token.

It is eaten by the scanner. The parser will never see it. 
You simply cannot define "&if' as an identifier. The parser will always see 'if'.

scanner.pas around line 4607.

And modifying the scanner for this exception is a REALLY bad idea.

Michael.