APL Cultivation was a series of 90-minute live chat lessons given by Adám Brudzewsky in the APL Orchard chat room in the period 2017–2020. Over the course of 2021–2022, Stefan Kruger edited the content into a book called APL Cultivations.
The first season consisted of 29 weekly sessions running from 18 October 2017 until 16 May 2018, covering most aspects of basic APL programming. Initially, the lessons were not organised, but were given completely impromptu. However, between lessons 2 and 3, Erik Konstantopoulos bookmarked the first two lessons using Stack Exchange's chat conversation bookmarking feature, and thus established the lessons as a numbered series. The name was first used for lesson 15 at the end of January 2018, but was since applied retroactively to all such lessons.
The series continued on 28 November 2019, with more in-depth lessons every two-three weeks. This was sparked by interest among participants of a presentation by Morten Kromberg and Aaron Hsu called Pragmatic Array Oriented Functional Programming, held during Jio talks 2019, after which a series of "APL Hacknights" were to be held in the APL Orchard. However, the audience of the first such eventtypos turned out mostly to be people who had not been at the Jio talk, and it was decided to fold this new series into a continuation of the previous one. This series ran for 20 sessions until 25 August, 2020.
Lessons
First season
| Lesson |
Title |
Date
|
| 1 |
Introduction to Arrays in APL |
Oct 18, 2017
|
| 2 |
Diving Into Functions in APL |
Oct 25, 2017
|
| 3 |
Some APL Operators: <source lang=apl inline>/ ⌿ \ ⍀ ¨ ⍣ ⍨</syntaxhighlight> |
Nov 1, 2017
|
| 4 |
More APL operators: <source lang=apl inline>∘ @ ⌶</syntaxhighlight> |
Nov 8, 2017
|
| 5 |
Even more APL operators: <source lang=apl inline>⌺ ⌸</syntaxhighlight> |
Nov 15, 2017
|
| 6 |
APL functions: <source lang=apl inline>+-×÷*⍟⌹○!? !⌈⌊⊥⊤⊣⊢ =≠≤<>≥≡≢ ∨∧⍲⍱ ↑↓</syntaxhighlight> |
Nov 22, 2017
|
| 7 |
APL functions: <source lang=apl inline>⊂⊃⊆⌷</syntaxhighlight> |
Nov 29, 2017
|
| 8 |
APL functions: <source lang=apl inline>⍋⍒ ⍳</syntaxhighlight> |
Dec 6, 2017
|
| 9 |
APL functions: <source lang=apl inline>⍸∊⍷∪∩~ /\⌿⍀ ,⍪</syntaxhighlight> |
Dec 13, 2017
|
| 10 |
APL functions <source lang=apl inline>⍴⌽⊖⍉ ⍎⍕</syntaxhighlight> |
Dec 20, 2017
|
| 11 |
System Functions: behaviour, session |
Jan 3, 2018
|
| 12 |
Constants, tools & external utils |
Jan 10, 2018
|
| 13 |
Code management, I/O, dates, Unicode files, errors |
Jan 17, 2018
|
| 14 |
Stack & workspace info, misc |
Jan 24, 2018
|
| 15 |
Control structures |
Jan 31, 2018
|
| 16 |
APL objects: namespaces |
Feb 6, 2018
|
| 17 |
APL objects: classes |
Feb 14, 2018
|
| 18 |
Class constructors & destructors |
Feb 21, 2018
|
| 19 |
APL objects: class properties |
Feb 27, 2018
|
| 20 |
APL objects: many-in-one properties, inheritance |
Mar 7, 2018
|
| 21 |
APL objects: overriding methods, keyed/numbered properties |
Mar 14, 2018
|
| 22 |
Programming techniques and style |
Mar 21, 2018
|
| 23 |
Transcribing to and reading trains |
Mar 28, 2018
|
| 24 |
<source lang=apl inline>⎕R</syntaxhighlight> and <source lang=apl inline>⎕S</syntaxhighlight> |
Apr 3, 2018
|
| 25 |
Understanding function application |
Apr 11, 2018
|
| 26 |
Concurrent APL threads |
Apr 18, 2018
|
| 27 |
Lookup without replacement |
Apr 25, 2018
|
| 28 |
User commands |
May 9, 2018
|
| 29 |
More user commands |
May 16, 2018
|
Second season
| Lesson |
Title |
Date
|
| 30 |
Counting words faster |
Nov 28, 2019
|
| 31 |
Tradfns |
Dec 19, 2019
|
| 32 |
Basic use of ⍤ |
Jan 2, 2020
|
| 33 |
Advanced use of ⍤ |
Jan 16, 2020
|
| 34 |
<source lang=apl inline>f⍣k</syntaxhighlight> in depth |
Jan 30, 2020
|
| 35 |
<source lang=apl inline>f⍣g</syntaxhighlight> in depth |
Feb 13, 2020
|
| 36 |
The variant option operator: <source lang=apl inline>⍠ ⎕OPT</syntaxhighlight> |
Feb 27, 2020
|
| 37 |
<source lang=apl inline>⊥</syntaxhighlight> in depth |
Mar 12, 2020
|
| 38 |
<source lang=apl inline>⊤</syntaxhighlight> in depth |
Mar 26, 2020
|
| 39 |
Array programming techniques |
Apr 7, 2020
|
| 40 |
Condition-controlled loops |
Apr 21, 2020
|
| 41 |
<source lang=apl inline>⌹</syntaxhighlight> in depth |
May 5, 2020
|
| 42 |
Array coding style in depth |
May 12, 2020
|
| 43 |
Complex numbers in depth |
Jun 2, 2020
|
| 44 |
Simple plotting (with Nicolas Delcros) |
Jun 16, 2020
|
| 45 |
Simple plotting continued (with Nicolas Delcros) |
Jun 30, 2020
|
| 46 |
Unique mask <source lang=apl inline>≠</syntaxhighlight> and constant <source lang=apl inline>⍨</syntaxhighlight> |
Jul 14, 2020
|
| 47 |
Atop <source lang=apl inline>⍤</syntaxhighlight> and Over <source lang=apl inline>⍥</syntaxhighlight> |
Jul 28, 2020
|
| 48 |
<source lang=apl inline>⎕C</syntaxhighlight> <source lang=apl inline>⎕DT</syntaxhighlight> <source lang=apl inline>1200⌶</syntaxhighlight> |
Aug 11, 2020
|
| 49 |
Extensions in 18.0: <source lang=apl inline>⊂</syntaxhighlight> <source lang=apl inline>⍸⍣¯1</syntaxhighlight> <source lang=apl inline>⎕JSON</syntaxhighlight> |
Aug 25, 2020
|
External links