> On Mar 2, 7:29 am, Andrew Haley
> wrote:
>

>> Cesar Rabak yahoo.com.br> wrote:

>>> keo...@gmail.com escreveu:
>>> [snipped]

>>>> As I am interested but not yet very proficient in stack based
>>>> programming languages, I ask you: how would you solve this problem in
>>>> FORTH?

>

>>> Did you study the solution given in the post # 53?

>

>> The code is over-factored, making it hard to read. There is also too
>> much stack noise: this problem really doesn't need DUP SWAP etc.

>
> I don't see any problem with that code. It looks fine to me.
>

>> A simple solution is

>

>> : bang
>> 100 1 do
>> i 15 mod 0= if ." FizzBuzz " else
>> i 3 mod 0= if ." Fizz " else
>> i 5 mod 0= if ." Buzz " else
>> i . then then then
>> loop ;

>
> Your solution looks fine to me too.
>
> Your code brings up something for me. I notice those three then then
> thens. Forth doesn't usually have a way to skip over the rest of a
> loop and then repeat. We have ways to break out of the loop, but not a
> command to skip to the end of the loop. So we have ugly things like
> then then then to do it, both in DO loops and in BEGIN loops.
>
> I've never felt the need for an improvement there. Multiple THENs
> don't actually cause a performance hit, only a very slight compile-
> time hit. Wil Baden made his THENS command which palliates it.
>
> Somehow I never noticed until now that you can get a similar result
> with multiple BEGINs.
>
> : bang1
> 0 BEGIN BEGIN 1+ cr
> dup 3 mod DUP 0= if ." Fizz" then
> over 5 mod dup 0= if ." Buzz" then
> or 0= UNTIL
> dup .
> dup 100 >
> UNTIL ;
>
> I certainly don't want to propose this as clear writing or even
> adequate code (like, the method would run over if you changed the
> limit to 99BEG), it's just that I never thought of this as a single
> loop with a continuation. If you had a word that was just like UNTIL
> except it left a copy of the dest, it would effectively skip to (but
> not past) the end of the loop on failure or execute the rest of the
> loop on success.
>
> BEGIN ... SKIP-TO-REPEAT ... SKIP-TO-REPEAT ... SKIP-TO-REPEAT ...
> WHILE ... REPEAT
>
> Again, I've never felt the need to have something like this, I've
> always just accepted THEN THEN THEN as good enough.
>
> Additional control structure words might someimes make the flow of
> control clearer, provided we all remembered what they did. What we
> already have is adequate.
>
> : bang2
> 101 0 do
> i 3 mod 0= 1 and
> i 5 mod 0= 2 and or
> case
> 0 of i . endof
> 1 of Fizz endof
> 2 of Buzz endof
> 3 of FizzBuzz endof
> endcase
> loop ;
>
> This one doesn't read better either, but at least the most common
> cases are tested the most often. A jump table might be more efficient
> but also less readable.
>
> : DUP. dup . ;
>
> CREATE TABLE
> ' DUP. ,
> ' Fizz ,
> ' Buzz ,
> ' FizzBuzz ,
>
> : do-it
> CELLS TABLE + @ EXECUTE ;
>
> : which-action ( n -- n 0|1|2|3 )
> dup
> i 3 mod 0= 1 and
> i 5 mod 0= 2 and or ;
>
> : Bang3
> 0 begin
> 1+ dup 101 <
> while
> which-action do-it
> repeat drop ;
>
> I guess when the first methods I learned give a result that isn't too
> long, then that's the most readable. There's nothing hard to
> understand about nested IF THENs. Just, if they get too complex you
> can lose track of how deeply they're nested and which places which
> result happens.