Re: recursion

On 16/07/2024 10:02 pm, sjack wrote:

Anton Ertl <anton@mips.complang.tuwien.ac.at> wrote:

forward foo
>
: bar ( n -- ) dup . 1- foo ;
>
: foo ( n -- ) dup 0> if bar else drop then ;
>
5 foo \ prints "5 4 3 2 1 "
>

 
 
Toad code using Wil Baden type local macros ( /MM: MM ):
 
"dup . 1- myself" /mm: bar  OK
 
: foo dup 0> if mm bar else drop then ;  OK
 
5 foo 5 4 3 2 1  OK
 
Note: The macro BAR does not remain in the system image.

I would use:

  defer foo

  : bar ( n -- ) dup . 1- foo ;

  :noname ( n -- ) dup 0> if bar else drop then ; is foo

  5 foo \ prints "5 4 3 2 1 "

DEFER may not be as fast as a directly patched definition but neither
has that prevented a generation from using it.