,---------------.
| Contributions |
`---------------´


,------------------------------------------
| 2020-04-10 23:20:57  rrt  wrote:
| requestClarification - Reference implementation does not seem to cope with changes to the stack
| see: https://forth-standard.org/standard/tools/BracketELSE#contribution-134
`------------------------------------------
I just noticed, having used the reference implementation of [IF]/[ELSE]/[THEN] in my own Forth system, that it keeps markers on the data stack, and hence does not work correctly if you write e.g. `1 [IF] 2 [ELSE] 3 [THEN]`. I have stared at the standard text, and it does not seem to forbid this usage; also I see that e.g. GForth makes use of `[IF]...[ELSE]....[THEN]` to put values on the stack in exactly this way (and GForth has its own rather different implementation.

Assuming I've not misunderstood something here, could a warning about this limitation be added to the reference implementation until such time as it is improved?


,---------.
| Replies |
`---------´


,------------------------------------------
| 2020-04-04 15:40:24  ikysil  replies:
| referenceImplementation - Suggested reference implementation
| see: https://forth-standard.org/standard/core/FILL#reply-362
`------------------------------------------
Implementation with `BEGIN` leaves `c-addr u` on the stack.

Corrected version:
```
: FILL ( c-addr u char -- )
   ( If u is greater than zero, store char in each of u consecutive characters of memory beginning at c-addr.)
   >R BEGIN
      DUP 0<>
   WHILE
      OVER R@ SWAP C!
      1 /STRING
   REPEAT
   2DROP
   R> DROP
;
```


,------------------------------------------
| 2020-04-11 10:20:02  rrt  replies:
| requestClarification - Reference implementation does not seem to cope with changes to the stack
| see: https://forth-standard.org/standard/tools/BracketELSE#reply-363
`------------------------------------------
This is my misreading, and an unfortunate combination of circumstances in my own code that caused me to leap to this conclusion. So please delete my previous query!