All tips of the day
Factor handbook » Developer tools » Help system » Tips of the day


Generate stand-alone applications from vocabularies with the UI application deployment tool.

Press ⌃I to print the stack effect of the code in the input field without executing it (Stack effect checking).

Press ⌃W to single-step through the code in the input field (UI walker).

Press ⌃T to time execution of the code in the input field (Timing code and collecting statistics).

All UI developer tools support a common set of UI tool keyboard shortcuts. Each individual tool has its own shortcuts as well; the F1 key is context-sensitive.

To look at the most recent error, run :error. To look at the most recent error's callstack, run :c.

Learn to use Dataflow combinators.

Learn to use Editor integration to be able to jump to the source code for word definitions from the listener.

Check out to get answers to frequently-asked questions.

Consider joining the Factor Discord server: The developers are active and happy to help.

You can write documentation for your own code using the Help system.

You can write graphical applications using the UI framework.

Power tools: see, edit, help, about, apropos, time, infer.

Tips of the day implement the Definition protocol and new tips of the day can be defined using the TIP: parsing word.

Try some simple demo applications:
"demos" run

Then look at the source code in extra/.

To save time on reloading big libraries such as the furnace web framework, save the image after loading them using the save word.

Use the leaks. combinator to track down resource leaks.

You can read documentation by pressing F1.

The listener tool remembers previous lines of input. Press ⌃P and ⌃N to cycle through them.

When you mouse over certain objects, a black border will appear. Left-clicking on such an object will perform the default operation. Right-clicking will show a menu with all operations.

The status bar displays stack effects of recognized words as they are being typed in.

Press TAB to complete word, vocabulary and Unicode character names. The latter two features become available if the cursor is after a USE:, USING: or CHAR:.

If a word's vocabulary is loaded, but not in the search path, you can use restarts to add the vocabulary to the search path. Auto-use mode (⌘U) invokes restarts automatically if there is only one restart.

Scroll the listener from the keyboard by pressing ⌘PAGE_UP and ⌘PAGE_DOWN.

Press F2 or run refresh-all to reload changed source files from disk.

On Windows: use C+Break to interrupt tight loops in your code started in the listener, such as
[ t ] [ ] while

Caution: this may crash the Factor runtime if the code uses cooperative multitasking or asynchronous I/O.

Editor gadgets support undo and redo; press ⌘Z and ⌘Y.

Learn the keyboard shortcuts used in Editor gadgets.

Use apropos to search for words, vocabularies and help articles.