Dyalog APL Vision

This is my vision for a realistic development of core Dyalog APL, including extending the domains of existing primitives/quad-names, and adding a few new ones. Requires Dyalog APL version 18.2 or higher.

How to use

You can easily play with these almost like you use normal Dyalog APL in a session:

Initialisation

From within Dyalog APL 18.2 or higher, enter ]get path/dyalog_vision or to import directly from GitHub ]get https://github.com/abrudz/dyalog_vision

Running code

You have three options:

1. Use the extensions directly with the glyph names, e.g. 4 1 dyalog_vision.RightShoeUnderbar ⎕A.
2. Use dyalog_vision.∆FIX as a drop in for ⎕FIX.
3. Use dyalog_vision.⍙REPL # to start a (limited) session where the glyphs work. Enter → to exit.

Content

• All scalar functions support leading axis agreement.

• All set functions support arguments of any rank.

• ⎕C and monadic ⎕UCS are scalar functions.

• In addition, the following is included:

Name	Symbol	Type*	Extension	Examples
CircleDiaeresis	⍥	🔵✅	Depth when right operand is array. This is similar to Rank (⍤) but applies at nesting level.	f⍥0 applies f like a scalar function and f⍥1 applies to flat subarrays. f⍤1⍥1 applies to flat vectors.
DelDiaeresis	⍢	🔺	Under (a.k.a. Dual). Like f⍥g but conceptually inverts the right operand when done. If g is a selection function, it puts the data back where it came from	-⍢(2 3∘⊃) negates the 2nd element's 3rd element.
DelTilde	⍫	🔺	Obverse; ⍺⍺ but with inverse ⍵⍵	×⍢(FFT⍫iFFT)
DollarSign	$	🔺	string enhancement ${1}:1⊃⍺, ${expr}:⍎expr, \n:JSON	'Dyer' 'Bob'$'Hi, ${2} ${1}! $'Hi, ${first} ${last}! $'2×3=${2×3}'
DownArrow	↓	🔵	dyad allows long ⍺	0 1↓'abc' gives 1 2⍴'bc'
DownTack	⊤	⚠	⊥⍣¯1 when left argument is scalar	2⊤123 gives 1 1 1 1 0 1 1
EpsilonUnderbar	⍷	🔶	monad: Type (like ∊ with ⎕ML←0)	⍷1'a'# gives 0' '#'
JotUnderbar	⍛	🔺✅	reverse composition X f⍛g Y is (f X) g Y and default argument	⌽⍛≡ checks for palindromes. a-⍛↑b takes the last a from b.
LeftShoe	⊂	🔵	dyad allows partitioning along multiple leading axes	(⊂1 1)⊂matrix separates out the first row and column.
LeftShoeUnderbar	⊆	🔵	dyad allows partitioning along multiple leading axes	(⊂1 0 1 1)⊆4 4⍴⎕A splits off the first row and column, and removes the second.
QuadEqual	⌸	🔵	allow array operand to be vocabulary (then uses {⊂⍵} as internal operand)	≢¨'ACGT'⌸'ATT-ACA' gives 3 1 0 2
QuadDiamond	⌺	🔶	auto-extended ⍵⍵, allows small ⍵, optional edge spec(s) (0:Zero; 1:Repl; 2:Rev; 3:Mirror; 4:Wrap; -:Twist) with masks as operand's ⍺	Life on a cylinder: 0 4 Life⌺3 3
Rho	⍴	🔵	dyad: negatives reverse axis, 0.5 auto-size rounding down, 1.5 auto-size rounding up, 2.5 auto-size with padding	Reshape into two columns: 0.5 2⍴data
RightShoeUnderbar	⊇	🔺✅	monad: last (⊃⌽,⍵) dyad: select (⌷⍨∘⊃⍨⍤0 99)	3 1 2⊇'abc' gives 'cab'
Root	√	🔺	(Square) Root	√25 gives 5 3√27 gives 3
UpArrow	↑	🔵	allows long ⍺	2 3↑4 5 gives 2 3⍴4 5 0 0 0 0
Vel	∨	🔶	monad: demote (,[⍳2])	∨2 3 4⍴⎕A gives 6 4⍴⎕A
Wedge	∧	🔶	monad: promote (⍵⍴⍨1,⍴⍵)	'ABC'⍪⍥∧'DEF' gives 2 3⍴⎕A
∆EM	⎕EM	🔵	Self-inverse ⎕EM	⎕EM'RANK ERROR' 'WS FULL' gives 4 1
∆NS	⎕NS	🔵	Accepts ref left arg. Name Set: The list of values to copy into the new/target namespace can have 2-element name-value vectors, setting the name to the given value	ref←⎕NS('Abe' 10)('Bea' 12) ref⎕NS⊂'Carl' 8
∆NG	⎕NG	🔺	Name Get	ref⎕NG'Bea' 'Abe'
∆SIGNAL	⎕SIGNAL	🔵	Allows ⎕DMX-style ref argument	⎕SIGNAL ⎕DMX

* 🔺 new feature 🔶 added valence 🔵 expanded domain ⚠ breaking change ✅ scheduled for 20.0 (except monadic ⊇)