Version 5 Features
Introduction to APL
Writing a Function
Overview of APL
Bringing up the QuickSym window
The QuickSymTM feature of APLX allows you to enter special APL symbols without using a special keyboard layout. By pressing a single key (the 'Menu' key in Windows, which is usually to the right of the space bar next to the Ctrl key, or a function key - by default F1 - under MacOS), you can bring up a panel which displays the APL symbols:
You can now enter one or more APL symbols by using the mouse to click on the corresponding image in the QuickSym pop-up window. To assist in selecting the character, hovering the mouse over a symbol brings up a brief description of what it does (if it has one-argument and two-argument forms which have different functions, these will be shown on separate lines).
Using the keyboard with the QuickSym window
The QuickSym window is designed so that it is there when you need it, but gets out of the way when you don't. Once you have displayed the QuickSym window, the keyboard behaves as follows:
- Any key which produces a printing character behaves as normal. This means that you can freely mix typing at the keyboard, and using the mouse to enter symbols from the QuickSym window. For example, with the line shown in the picture, the user has typed xx and then brought up the QuickSym window. By using the mouse to select the assignment arrow
← (in the bottom left corner), and then typing 32, the line will read xx
- Pressing Enter (or Return) closes the QuickSym window. The keystroke is passed to the underlying window. Thus, in the above example, if the user now presses Enter, the QuickSym window will disappear, and the line of APL xx
←32 will be executed.
- Backspace and Delete act in the normal way, and do not close the QuickSym window. This means you can easily correct mistakes in the line you are entering.
- The cursor movement keys (Cursor Left, Cursor Right, Cursor Up, Cursor Down, Page Up, Page Down, and if appropriate Home and End) allow you to navigate around the QuickSym window by using the keyboard rather than the mouse. The currently-selected character will be highlighted in the display. Pressing Ctrl-Enter (Cmd-Enter on the Macintosh) inserts the currently-selected character in the line you are entering, without closing the QuickSym window.
- Pressing the Help key (F1 on Windows, Ctrl-H on Linux) brings up the APLX Help page for the selected character.
- The Escape key, or pressing the Menu or function key again, closes the QuickSym pop-up, without having any other effect.
- Any other key closes the QuickSym window, and is ignored.
The contextual menu
Right-clicking on a character in the QuickSym Window (or click-and-hold on the Macintosh) brings up a pop-up menu:
This offers the following options:
- 'Help on symbol' brings up the APLX Help page for the selected symbol (this is the same as pressing F1 under Windows, or the Help key under MacOS, when you have selected a symbol with the cursor keys). If the symbol has more than one Help page, there will normally be a link on the page which appears. If the symbol does not have a Help page, this option will be disabled.
- 'Copy symbol to clipboard' puts the selected character into the clipboard. This is useful if you just want to copy an APL character to another application.
- 'Show symbol on keyboard' brings up the keyboard layout window, with the key on which the character appears highlighted. This is very useful if you are familiarising yourself with the APL keyboard layout, or are used to a different APL layout: