Re: RPG

[Vernon Hamberg <vhamberg@xxxxxxxxxxxxxxx>]

Hi Mark

Good information - I was coming from a couple Google hits about 
semicolon use.

Still, I think my point is fair, that a semicolon just isn't all that 
weird or crazy.

As I think about it, why did IBM decide to use the semicolon as a 
terminator? I take a shot at reverse-engineering, where I'm usually in 
murky waters!

Maybe it's related to the record-based structure of source members, and 
with parsing that, where a terminator makes it easier - other languages 
seem to use a CRLF or some such to delimit statements - there is no CRLF 
in source files - now I haven't put source into stream files yet, so 
can't say if those delimiters are there.

Enough frivolous speculation!!

Regards
Vern

On 7/19/2016 11:14 PM, Mark S Waterbury wrote:
> Vern:
>
> In Algol, Pascal and Ada, a semicolon is used as a statement 
> separator, not  a  statement terminator.    So you might have:
>
>     if a < b then  begin
>         z  := a;
>         end
>     else begin
>         z := b;
>         end;
>
> (The final semicolon is only needed when this if-else statement is  
> followed by another statement in a compound statement block.)
>
> In PL/I, designed by IBM in the mid-1960s, the semicolon is a 
> statement terminator, as currently used in free-form RPG IV. For example:
>
>     IF (A < B) THEN DO;
>         Z = A;
>         END;
>     ELSE DO;
>         Z = B;
>         END;
>
> C was influenced by PL/I in many ways -- C statements end with a 
> semicolon, except when braces are used, in which case, a ";" never 
> follows the final "}" closing brace.  For example:
>
>         if (a > b)
>             z = a;
>         else
>             z = b;
>
>  -or-
>
>     if (a > b) {
>         z = a;
>         }
>     else {
>         z = b;
>         }
>
> HTH,
>
> Mark S. Waterbury
>
> > On 7/19/2016 4:56 PM, Vernon Hamberg wrote:
> > Crazy quirks? (See John's statement below) Semicolons?
> >
> > Let's see, languages like C, Pascal, Algol, Ada, PL/I, et al, used 
> > semicolons to indicate the end of a line - and Javascript today can 
> > use them although optional, last I looked.
> >
> > Not so crazy anytime, methinks!
> >
> > Vern