SET in Ada?

SET in Ada?

[Alfred]

Hi I'm trying to convert some Modula code to Ada. There is a statement
like this:

IF i in {1,5,13,21}  THEN ...

How could this be translated to Ada, because as far as I know, Ada has
no similar "SET" handling.

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Re: SET in Ada?

[Jeffrey Creem]

If you need general purpse set operations then there are quite a few data
structure libraries out there you
can use.

if you are just trying to simulate the exact expression you wrote below then

case I is
  when 1 | 5 | 13 | 21 =>
    Do_The_Then_Stuff;
  when others =>
    Do_The_Else_Stuff;
end;

"Alfred" <SPAM@alfred-hilscher.de> wrote in message
news:3E7203B0.B5B7E076@alfred-hilscher.de...
> Hi I'm trying to convert some Modula code to Ada. There is a statement
> like this:
>
> IF i in {1,5,13,21}  THEN ...
>
> How could this be translated to Ada, because as far as I know, Ada has
> no similar "SET" handling.
>
> --
> ----------------------------------------------
> To send me email replace "SPAM" by "Jedermann"
> ----------------------------------------------

Re: SET in Ada?

[Robert A Duff]

Alfred <SPAM@alfred-hilscher.de> writes:

> Hi I'm trying to convert some Modula code to Ada. There is a statement
> like this:
> 
> IF i in {1,5,13,21}  THEN ...
> 
> How could this be translated to Ada, because as far as I know, Ada has
> no similar "SET" handling.

The corresponding feature in Ada is a packed array of Booleans:

    type Bit_Set is array(...) of Boolean;
    pragma Pack(Bit_Set);
    Set: constant Bit_Set := (1 | 5 | 13 | 21 => True, others => False);
    if Set(I) then...

- Bob

Re: SET in Ada?

[Jeffrey Carter]

Alfred wrote:
> Hi I'm trying to convert some Modula code to Ada. There is a statement
> like this:
> 
> IF i in {1,5,13,21}  THEN ...
> 
> How could this be translated to Ada, because as far as I know, Ada has
> no similar "SET" handling.

You could use PragmArc.Set_Discrete from the PragmAda Reusable Components

http://home.earthlink.net/~jrcarter010/pragmarc.htm

In which case your example would be written as

if Member (I, Make ((1, 5, 13, 21)) then

However, that's a poor use of sets. If you're not defining sets and 
checking for membership in a set variable you probably want a case 
statement.

-- 
Jeff Carter
"That was the most fun I've ever had without laughing."
Annie Hall