amforth-devel

[Amforth-devel] Help with word definition- redef

[pito <pi...@vo...>]

Hi dear friends,
as I am a newbie in forth I would kindly ask you for a minor help with
a definition of a new word - "redef"

: redef ( string"word" -- n1 )

1. n1 = 0, it finds the address ADDR_LAST of "word" (from the newest
side - lefthandside)and memorise it; if not n1=-1 and exit
2. it finds the address of the next "word" (the next olderer in the word
list) and replaces its address with the address in ADDR_LAST; n1++
3. repeats till the end of the wordlist (to the very righthandside word)

;

Example:
> words
redef sqrt power voltage current sqrt current sqrt power sqrt .......
> sqrt redef
3 ok
> words
redef sqrt power voltage current SQRT current SQRT power SQRT .......

where the SQRT (capitals for clarity only) will have a JUMP to sqrt in
their header. So any call to sqrt, even from old instances in any other
older words (which are using sqrt) will point to sqrt.
So at the end of day the newest sqrt (very lefthanside) will be used
only.
Any help would be appreciated. Pito.

Re: [Amforth-devel] Help with word definition- redef

[pito <pi...@vo...>]

Correction:
2. it finds the address of the next "word" (the next olderer in the word
list) and replaces its header with a JUMP to the address in ADDR_LAST;
n1++


----- PŮVODNÍ ZPRÁVA -----
Od: "pito" <pi...@vo...>
Komu: amf...@li...
Předmět: Help with word definition- redef
Datum: 5.7.2010 - 18:19:43

> Hi dear friends,
> as I am a newbie in forth I would kindly ask you for
> a minor help with
> a definition of a new word - "redef"
> 
> : redef ( string"word" -- n1 )
> 
> 1. n1 = 0, it finds the address ADDR_LAST of "word"
> (from the newest
> side - lefthandside)and memorise it; if not n1=-1 and
> exit
> 2. it finds the address of the next "word" (the next
> olderer in the word
> list) and replaces its address with the address in
> ADDR_LAST; n1++
> 3. repeats till the end of the wordlist (to the very
> righthandside word)
> 
> ;
> 
> Example:
> > words
> redef sqrt power voltage current sqrt current sqrt
> power sqrt .......
> > sqrt redef
> 3 ok
> > words
> redef sqrt power voltage current SQRT current SQRT
> power SQRT .......
> 
> where the SQRT (capitals for clarity only) will have
> a JUMP to sqrt in
> their header. So any call to sqrt, even from old instances
> in any other
> older words (which are using sqrt) will point to sqrt.
> So at the end of day the newest sqrt (very lefthanside)
> will be used
> only.
> Any help would be appreciated. Pito.
> 
> 
> 
> 

Re: [Amforth-devel] Help with word definition- redef

[Matthias T. <mt...@we...>]

Hi Pito,

> Hi dear friends,
> as I am a newbie in forth I would kindly ask you for a minor help with
> a definition of a new word - "redef"
> 
> : redef ( string"word" -- n1 )
> 
> 1. n1 = 0, it finds the address ADDR_LAST of "word" (from the newest
> side - lefthandside)and memorise it; if not n1=-1 and exit
> 2. it finds the address of the next "word" (the next olderer in the word
> list) and replaces its address with the address in ADDR_LAST; n1++
> 3. repeats till the end of the wordlist (to the very righthandside word)


That's definitly not a task for a forth "beginner" and goes very deep
into the code of amforth. Sorry, but I cannot provide any assistance
here and now.

Matthias