Learning resources

"I have long been struck by the contrast between the success with which the adventurous learn APL by simply using it, and the frequent failure of lecture courses to communicate the simplicity and applicability of the language." Ken Iverson. A Working Introduction to APL, 1981.

To facilitate self-study, the resources here are classified by target audience. However, if you get stuck, don't hesitate to request help in the APL Orchard chat room or ask a question on Stack Exchange.

For non-programmers

Some of the best resources for somebody new to APL and programming in general are:

• APL Wiki's simple examples
• The Learn tab on TryAPL
• The book Mastering Dyalog APL by Bernard Legrand
• The book APL2 at a Glance by Jim Brown, Sandra Pakin, and Ray Polivka (also in German)
• Learning APL with APLX (also as PDF)
• The Zark APL Tutor
• APL a Day: Introduction, Functions, Arrays, Values, Arrays have Shape
• A Practical Introduction to APL 1 & 2 (3 & 4 is for experts)
• Découvrez le langage APL: parts 1, 2, 3 by Eric Schrafstetter (in French)
• Learn APL with neural networks (video series)
• MENACE in APL (An early Reinforcement Learning project reimplemented in APL)
• The tutorial from the old APL Wiki
• APLtrainer tutorials (video series)

Follow one or a couple of these tutorials through and play around a bit. To learn APL the advice is similar to that for learning other languages: have a goal (something you want to accomplish) and try to do it. Along the way you are sure to come across the pitfalls and gotchas of the language, and with time you may come to understand what APL thinking means.

For programmers unfamiliar with APL

This is a list of tutorials and other resources of interest to someone who knows about programming or is familiar with another programming language, but wants to learn more about APL.

• APL Wiki's advanced examples
• APL Wiki's Books
• APL Wiki's Papers
• APL Cultivation (chat lessons)
• TryAPL online interpreter with lessons
• APL Workshop (self-study course)
• Learn X in Y minutes
• Let's Learn A Programming Language
• The book Mastering Dyalog APL by Bernard Legrand
• The book APL2 at a Glance by Jim Brown, Sandra Pakin, Ray Polivka (also in German)* Zark tutorial
• Trying APL
• Learn APL with neural networks (video series)
• Artificial Neural Networks
• FizzBuzz
• APL deserves its renaissance too (interactive explanation of John Scholes' Conway's Game of Life)
• An Introduction to APL (video)

For novice APLers

• APL2 in Depth by Norman Thomson and Ray Polivka

• A Practical Introduction to APL 3 & 4

• Learn APL with neural networks (video series)

If you already have a fair grasp of APL's primitive functions and operators, you can sharpen your skills by challenging yourself with these:

• APLcart Quiz: Be challenged to write a function for a given task or to explain what a given function does. (Based on APLcart data.)

• APL Crosswords: 1 4 5 — Fill in expressions and snippets to fulfil all the clues.

• 2016 Year Game: Find APL expressions involving exactly the digits 2 0 1 6 in that order to equal the numbers 0 to 100.

• 2017 Code Golf Challenge: Find the shortest possible APL expression that evaluates 1…52 without using any number or character literals.

• Previous years' problems from the APL Problem Solving Competition. Phase I problems are available with automated testing.

• APL-eusis: A game for honing your ability to "think in APL".

• Advent of Code: A collection of small programming puzzles.

For advanced APLers

Here is a list of "how-to"s on various subjects:

• Learn APL with neural networks (video series)

• Error trapping with Dyalog APL

• Error trapping in Dyalog APL forms

• Calling APL from other languages

• Calling other languages from APL

• Performance tuning

• APL on the web

• Parallel computing

• Cryptography ← Migrate https://old.aplwiki.com/CryptographyWithDyalogAndDotNet

• WPF XAML Demo

Haven't used APL in a while?

Those who learned APL "in the early days" should note that several implementations have made significant extensions to the language and system in the last decade or two.

• General video: Dyalog APL for other APL users (assignment, control structures, namespaces, migration level, Bind, user-defined operators, dfns, error trapping, shyness, namelists, GCD, LCM, Power operator, and more)

• New primitive functions: ⊢ Same, Right; ⊣ Same, Left; ⌷ Materialise, Index; ≡ Depth, Match; ≢ Tally, Not Match; ≠ Nub Sieve; ⍸ Where, Interval Index; ⊆ Nest, Partition

• New primitive operators: ⍨ Commute, Constant; @ At; ∘ Bind, Beside; ⍤ Atop, Rank; ⍥ Over; ⍤ Rank; ⌸ Key; ⌺ Stencil; ⍠ Variant; & Spawn

• Lambdas (dfns): Intro; Details; Operators; The dfns workspace (collection of categorized utilities with extensive comments and notes)

• Tacit programming: Dyalog APL documentation: Intro; Details; short video; long video; APL Cultivation lesson; Function composition

• Other features and concepts: Keywords; Object-oriented programming; namespaces; Total array ordering; Leading axis theory; Complex numbers