I have noticed what I believe are some inconsistencies (bugs?) with how GNU APL handles reloading/overwriting/erasing of symbols which are 'trad fns' versus 'lambda fns'.
Consider the following )DUMP file:
--8<--
#!/usr/local/bin/apl --script
⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝
⍝ ⍝
⍝ sink.apl 2021-07-09 20:04:14 (GMT-8) ⍝
⍝ ⍝
⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝
Life←{↑1 ⍵∨.∧3 4=+/,¯1 0 1∘.⊖¯1 0 1∘.⌽⊂⍵}
∇a←MatToVecArray M
⍝⍝ Return rows in M as an array of vectors
⍝⍝ lambda (dfn) version: {(⊂⍺){⍺[⍵;]}¨⍳≢⍵} ⍝⍨M
a←{⊂M[⍵;]}¨⍳≢M
∇
--8<--
The above will )LOAD and )LOAD a second time, without error (as I presume it totally overwrites the current WS). However, )COPY or )PCOPY will give an error for the 'Life' function if it is already loaded into the current WS:
)copy sink Life
DUMPED 2021-07-09 20:04:14 (GMT-8)
)copy sink Life
DUMPED 2021-07-09 20:04:14 (GMT-8)
SYNTAX ERROR
Life←λ1
^ ^
Regular 'trad fns' can be re-loaded into the current WS without issue.
If I add in
⎕EX 'Life'
to sink.apl above the definition, )COPY and PCOPY will now succeed; but if I )DUMP this WS back to file, the ⎕EX is not part of the )DUMP output so problems will re-occur.
As an final note, as an APL newcomer: When is it preferable to use ⎕EX instead of )ERASE ?)
Thanks,
-Russ