Compy

A console-based Lua-programmable computer for children based on LÖVE2D framework.

Principles

• Command-line based UI
• Full control over each pixel of the display
• Ability to easily reset to initial state
• Impossible to damage with non-violent interaction
• Syntactic mistakes caught early, not accepted on input
• Possibility to test/try parts of program separately
• Share software in source package form
• Minimize frustration

Usage

Rather than the default LÖVE storage locations (save directory, cache, etc), the application uses a folder under Documents to store projects. Ideally, this is located on removable storage to enable sharing programs the user writes.

For simplicity and security reasons, the user is only allowed to access files inside a project. To interact with the filesystem, a project must be selected first.

Keys

Command	Keymap
Clear terminal	Ctrl+L
Stop project	Ctrl+Shift+S
Quit project (stop and close)	Ctrl+Shift+Q
Reset application to initial state	Ctrl+Shift+R
Exit application	Ctrl+Esc
Pause project	Ctrl+Pause
Toggle edit/run	F9
Input
Move cursor horizontally	⇦/⇨
Move cursor vertically	⇧/⇩
Go back in command history	PageUp
Go forward in command history	PageDown
Move in history (if in first/last line)	⇧/⇩
Jump to start	Home
Jump to end	End
Jump to line start	Alt+Home
Jump to line end	Alt+End
Insert newline	Shift+Enter ⏎
Delete current line	Ctrl+Y
Duplicate current line	Ctrl+D
Evaluate input	Enter ⏎
Editor
same as Input, except for:
Scroll up	PageUp
Scroll down	PageDown
Move selection (if in first/last line)	⇧/⇩
Move selection	Ctrl+⇧/⇩
Replace selection with input	Enter ⏎
additionally
Delete selected block	Ctrl+Delete
Delete selected block (if input is empty)	Ctrl+Y
Wipe input	Ctrl+W
Load selected content to input (discards previous content)	Esc
Insert selected content into input	Shift+Esc
Scroll to start	Ctrl+PageUp
Scroll to end	Ctrl+PageDown
Scroll up by one line	Shift+PageUp
Scroll down by one line	Shift+PageDown
Move selection to start	Ctrl+Home
Move selecion to end	Ctrl+End
Stop editor	Ctrl+Shift+S
move mode
Switch to moving ("pick up" selection)	Ctrl+M
Move selection	⇧/⇩
Move selection to start	Ctrl+Home
Move selecion to end	Ctrl+End
Cancel moving	Esc
Move line/block to selection and return to normal mode	Enter ⏎
search mode
Search definitions	Ctrl+F
Exit search	Esc
Jump to selected definition	Enter ⏎

Projects

A project is a folder in the application's storage which contains at least a main.lua file. Projects can be loaded and ran. At any time, pressing Ctrl-Shift-Q quits and returns to the console

• list_projects()

  List available projects.

• project(proj)

  Open project proj or create a new one if it doesn't exist. New projects are supplied with example code to demonstrate the structure.

• current_project()

  Print the currently open project's name (if any).

• run_project(proj?) / run(proj?)

  Run either proj or the currently open project if no arguments are passed.

• example_projects()

  Copy the included example projects to the projects folder.

• close_project()

  Close currently opened project.

• edit(file)

  Open file in editor. If it does not exist yet, a new file will be created. See Editor mode

Files

Once a project is open, file operations are available on it's contents.

• list_contents()

  List files in the project.

• readfile(file)

  Open file and display it's contents.

• writefile(file, content)

  Write to file the text supplied as the content parameter. This can be either a string, or an array of strings.

• runfile(file)

  Run file if it's a lua script.

Editor

If a project is open, the files inside can be edited or new ones created. Run the edit() command to do so.

When a file is opened, the editor is scrolled to the end by default, and entered input will be appended to the end.

To modify an existing line, navigate there with ⇧/⇩. Then load the text by pressing Esc, make the desired changes, then send it back with Enter ⏎

Happy with the modifications now, we can quit by pressing Ctrl-Shift-Q

Moving

Select the block you want to move and press Ctrl-M. Move the highlight with ⇧/⇩ and hit Enter ⏎ when you found it's new home.

Searching

Definitions can be searched with Ctrl-F. Pressing this combination switches to search mode, in which the definitions are listed, and there's a highlight, which can be moved as usual. Hitting Enter ⏎ returns to editing, highlighting the selected definition. To exit search mode without moving, press Esc.