Hi,
there is some inconsistency in depth reporting:
≡ U.V.W.X.Y.Z←0
0
≡ U
6
≡ U.V.W.X.Y.Z←,0
1
≡ U
6 ⍝ should be 7 ??
≡ U.V.W.X.Y.Z←⊂,0
2
≡ U
7 ⍝ should be 8 ??
Q: Does depth on structured variables not have a different meaning?
This takes me to an ancient idea of a 'name operator'.
Structured variables brought the idea back to light:-)
There are two 'name operators' in APL:
Nabla (∇) operates on names. ∇function_name -> edit function.
Dyadic Del (∆): S∆function, T∆function -> stop and trace a name
Both operators "take" the name. They are not modifying the name content.
One might argue the names being operated on are function names and
applying a plain operator to function content is not meaningful and
the distinction, to have operators acting on strings representing names
and to have operators acting on variable content is moot.
Lets see what happens if we made the distinction:
What is it?
name operator ←→ *NO* ⍝ I have not been looking for a special APL-like
character yet. I just use NO for the time being.
What does it?
My original idea was to save writing characters -> "quoting" :
suffix←'0001'
Instead of writing ⍎'VARNAME_' , suffix , ' ← 1234567890'
one could write VARNAME_ *NO *suffix ← 1234567890 -> VARNAME_ *NO
*suffix ←→ VARNAME_*0001*
suffix ← 1
Instead of writing ⍎'VARNAME_' , ('0005'⍕suffix) , ' ← 1234567890'
one could write VARNAME_ *NO *( '0005' ⍕ suffix ) ← 1234567890 ->
VARNAME_ *NO *( '0005' ⍕ suffix ) ←→ VARNAME_*0001*
Independent sets of name-characters are being joined by *NO* into a
valid name.
As a side effect, *NO* does even allow to express scarce arrays:
"VARNAME_ *NO¨ *(⍕1234567890+⍳9)"
as well as hashes: "VARNAME_ *NO¨ *('hash_value_a' 'hash_value_b')"
One can say in above cases *NO* is dyadic.
Next, why not extending the use of *NO *to apply common operators to
STRUCTURED.NAME (! not to the content STRUCTURED.NAME !)?.
A.B.C.D.E.F ← ⊂,0 ⍝ structured name with data
≡ A.B.C.D.E.F ←→ 2
≡ A.B.C.D.E ←→ DOMAIN ERRROR -> not a leaf-node
*NO* with Left Operators:
≡*NO *A ←→ 6 ⍝ zero on a plain variable name
⍴ *NO* A.B.C.D.E.F ←→ 6 ⍝ empty on a plain variable name
3↑*NO* A.B.C.D.E.F ←→ A.B.C
1 0 1 0 1 0 / *NO* A.B.C.D.E.F ←→ A.C.E
Monadic *NO*, binding to name characters.
*NO* A.B.C ⍳ *NO* B ←→ 2
*NO* D ∊ *NO* A.B.C.D ←→ 1
*NO* A.B.C.D.E.F [ 5 6 ] ←→ E.F
Rename a variable:
(*NO* A.B.C.D.E.F [ 2 ] ) ← *NO* OTHER ← → A.OTHER.C.D.E.F
... and so on.
Just wondering whether those thoughts have any merit.....
Best Regards
Hans-Peter
