Re: [Flashforth-devel] For-next and do-loop practise

[Mikael N. <mik...@pp...>]

Hi,
Some further thoughts:

a)  B A do ... loop
The case a) cannot be translated. It will execute as f).
f)  B A ?do ... loop

: testa #10 #2 - for r@ . next ;  ok<$,ram>
testa 7 6 5 4 3 2 1 0  ok<$,ram>

b) This will also execute as ?do.
B A ?do i . loop

: testb #10 #2 dup !p>r - for @p . p+ next r>p ;  ok<$,ram>
testb 2 3 4 5 6 7 8 9  ok<$,ram>

/Mike

On 16.6.2011 18:56, om1zz wrote:
> Mike, thanks! This should definately be put into you FF User Guide!!
>
> ?? d) e): K and L are arbitrary values which are added to the loop
> counter
> ?? not sure about the limits (the number of times it runs through
> the loop)
>
> a)   B A do ... loop
> B A - 1- for ... next
>
> : testa 10 2 - 1- for 0 . next ; ok<#,ram>
> testa 0 0 0 0 0 0 0 ok<#,ram>
>
> b)   B A do I ... loop
> B A dup !p>r - 1- for @p p+ ... next r>p
>
> : testb 10 2 dup !p>r - 1- for @p . p+ next r>p ; ok<#,ram>
> testb 2 3 4 5 6 7 8 ok<#,ram>
>
> c)   D C do
> B A do ... I J ... loop
> loop
>
> variable j
> D C dup !p>r - 1- for
> B A dup j ! - 1- for
> @p j @ ... p+ 1 j +!
> next r>p
> next
>
> variable j
> : testc
> 10 2 dup !p>r - 1- for
> 10 2 dup j ! - 1- for
> @p j @ . . p+ 1 j +!
> next r>p
> next ; ok<#,ram>
> testc  2 2 3 3 4 4 5 5 6 6 7 7 8 8 ok<#,ram>
>
> it shall be probably:
> ------------------------
> variable j
> : testc
> 10 2 dup j ! - 1- for
> 8 3 dup !p>r - 1- for
> @p j @ . . p+
> next r>p
> 1 j +!
> next ;
>
> testc 2 3 2 4 2 5 2 6 3 3 3 4 3 5 3 6 4 3 4 4 4 5 4
> 6 5 3 5 4 5 5 5 6 6 3 6 4 6 5 6 6 7 3 7 4 7 5 7 6 8 3
> 8 4 8 5 8 6 ok<#,ram>
>
>
> d)   B A do ... K +loop
> B A -  K / for ... next
>
> Issue: Here K is usualy a step of any value (not (B-A/K))
>
> e)   D C do
> B A do ... I J ... K +loop
> L +loop
>
> variable j
> D C dup !p>r - K / for
> B A dup j ! L / for
> @p j @ ... K p++ L j +!
> next r>p
> next
>
> Issue: Here K and L are usualy steps of any value (not (B-A/K))
>
> f)   B A ?do ... loop
> B A - dup if 1- for ... next then
>
> : testf 10 2 - dup if 1- for 0 . next then ; ok<#,ram>
> testf 0 0 0 0 0 0 0 ok<#,ram>
>
>