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 and extends Dyalog APL version 18.2. If Dyalog APL moves forward in ways that are incompatible with what is found here, the vision will be updated accordingly. This project should therefore not be relied on as stable.

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' '#'
Equal	=	🔶	monad: Rank (≢⍴)	=10 20 30 gives 1'
GreaterOrEqual	≥	🔵	monad: sort descending	≥3 1 4 1 5 gives 5 4 3 1 1
GreaterThan	>	🔵	monad: Join	>2 2⍴⍪¨1 2 3 4 gives 2 2⍴1 2 3 4
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.
LessOrEqual	≤	🔵	monad: sort ascending	≤3 1 4 1 5 gives 1 1 3 4 5
LessThan	<	🔵	monad: Major Cells	<2 2 2⍴⎕A gives (2 2⍴'ABCD')(2 2⍴'EFGH')
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
QuestionMark	?	🔵	dyadic allows ⍺ to be any shape (not just vector shape) and ⍵ is shape of array to select indices from	3 5?4 13 deals 3 hands of 5 cards from deck of 4 suits from A to K
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
∆NG	⎕NG	🔺	Name Get	ref⎕NG'Bea' 'Abe'
∆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
∆NV	⎕NV	🔺	Names and Values	`ref⎕NV -2 9
∆SIGNAL	⎕SIGNAL	🔵	Allows ⎕DMX-style ref argument	⎕SIGNAL ⎕DMX

* 🔺 new feature 🔶 added valence 🔵 expanded domain ⚠ breaking change ✅ scheduled for 20.0