There is plenty of documentation on what parts of APL do. APLcart seeks to answer How do I… questions.

APLcart is a searchable collection of over two thousand short APL phrases intended for both beginners and professionals, with content provided by the community. Knowledge of basic APL syntax is a prerequisite.

Note that Internet Explorer is not supported.

APLcart can also be used for exercising your APL skills.

→ See also the video introduction.

• APLcart is for finding out how to do things, not for finding out, for example, what a symbol means or what a system function does. Please use the language documentation for such purposes.

• The site may take some seconds to load due to the information being processed by the browser. Once ready, it does not require internet access any more.

• All code in APLcart assumes the latest version of Dyalog APL Unicode edition and system defaults, for example ⎕IO←1, ⎕ML←1, ⎕DIV←0.

See here how to use access-keys on your system.

• Hit here and start typing (access-key Q — for Query — to re-focus)
• Some entries have a ▸ which can be clicked to open example code in a sandbox
• Some entries have a ? which can be clicked to open online documentation
• Hit the logo ⊆⌈ in the top left corner to go to the source code (access-key A — for APLcart)
• Hit ? in the top left corner to start a new query (access-key E — for Explain)
• Hit × at the end of the input field to clear it (access-key X — for expunge)
• Hit # in the top right corner copy to the current search to the address bar (access-key C — for Copy)
• Hit ◐ in the bottom right corner to cycle theme (access-keys B for Black, G for Grey, W for White)
• Hit the result list to enable movement keys for scrolling (access-key Z)
• Hit the input field at the top to start a new query (access-key E — for Query)

DuckDuckGo allows you to search APLcart directly using the !aplcart bang. For example, searching for !aplcart 42 redirects to APLcart. This also means that if you set your browser's default search engine to DuckDuckGo, you can search APLcart directly from your browser address bar by prefixing your search with !aplcart.

The Windows Dyalog IDE allows using an online search when F1 is pressed with the cursor on an unknown word:

• Options ▸ Configure ▸ Help/DMX ▸ Use online help for non-Dyalog topics ▸ URL: https://aplcart.info/?q=%s

RIDE allows adding a website to its menu bar:

• Edit ▸ Preferences ▸ Menu, then below &Help insert &APLcart =https://aplcart.info

You can now press Alt-Alt,a to launch APLcart.

After clicking # simply copy the current address from your browser's address bar to share the current query. Note that your current theme is intentionally not included, to avoid blinding the recipient. Note that the result for such a URL isn't permanent; it depends on APLcart's content at the time of usage.

After aplcart.info you can add ? and the following options, separated by & if you want both a theme and a query:

• w select white theme
• b select black theme
• q=query prepopulate the Tell me about query field

For example, for a white interface looking for "find", use aplcart.info?w&q=find

To answer how do I questions, APLcart currently searches over 2000 entries:

• General syntax, like name f←Y
• Primitives, like !
• Control structures, like :If
• Keywords, like :Access
• System commands, like )CLEAR
• System functions, like ⎕SIGNAL
• System constants, like ⎕A
• System operators, like ⎕R
• System variables, like ⎕IO
• GUI objects, like HTMLRenderer
• I-beams, like 819⌶
• Errors numbers and messages, like 11::DOMAIN ERROR
• User commands, like ]Box
• A selection of simple dfns, dops, and derived functions like (0=|)
• All of dfns.dws, like dfns.cal (In APLcart, entries from here are prefixed dfns. . To use, insert {(⍎⍵⎕NS⍬).⎕CY⍵}'dfns' into your code, then call, for example, dfns.cal.)
• Performance idioms from Dyalog's idiom list, like {(+/∨\' '≠⌽⍵)↑¨↓⍵}
• Idioms from the APL2 idiom list, like (+/|) (fully updated to use modern APL)
• James A. Brown's favourite idioms (fully updated to use modern APL)
• All idioms from the FinnAPL idiom list, like (⊢⍳⌈/) (fully updated to use modern APL)
• The Yale/APL79 idiom list (fully updated to use modern APL)
• Selected entries from Dyalog's #onelinerwednesday series, like (×/⊢÷+/-2×⊢)
• Adapted entries from JSoftware's Phrase Book (translated to APL)
• and other entries submitted by users like you!

• links to documentation
• links to TIO examples (in progress)

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