Numpad

A dynamically typed expression language that can be programmed using just one hand on the numpad.

Hello world

The following program prints "Hello world!" and then calculates 1+1:

1..*.72..*.101..*.108..*.108..*.111..*.32..*.119..*.111..*.114..*.108..*.100..*.33..*.10..1+1

Easy right? Next we'll try sorting a list with 5 elements:

1..100//.*2..*3./
2..5
3../.20..40..11..1..16./
100..101-**100..102-+*/.*100./+1..103-0..104-0..105-0..*106
106..**/.102..107./++/.*101./+-*103
107..**/.111..108./++/.*101./+-*104
108..**/.109..110..110./+1++/.*/.*102./+*103./+-*/.*102./+*104
109..105-*/.*102./+*103.././.*102./+*103./-*/.*102./+*104.././.*102./+*104./-*105..*110
110..104-1+*104..*107
111..103-1+*103..104-0..*106

Uhm, ok, maybe not that easy. A full breakdown of the language is available on Numpad's website.

Build

In order to build the compiler from source, run the following:

cargo install --path .

This should add numpad to your ~/.cargo/bin or equivalent. To uninstall it again, run:

cargo uninstall numpad

Run source code

By convention the extension for Numpad programs is .num:

numpad examples/hello.num

Start a REPL

Running numpad with no arguments starts the REPL. A prompt will appear, starting with | , where you can type in your code:

numpad
| 

Input

Although you can use both hands and an entire keyboard to program... what fun is that?

Using only the numpad, the following keys are available to you:

• Numbers : 0 1 2 3 4 5 6 7 8 9
• Dot : .
• Operators : + - * /
• Cursor movement : ← → Home End
• History : ↑ ↓
• Editing : Del
• Input : Enter
• Terminal dependent : Insert PgDn PgUp

Remember to use NumLock to toggle between characters and actions.

Press Enter twice to evaluate from the entry point:

numpad
| 1..*2
| 2..5
| 
Output: (5)
| 

End the REPL session by typing 4 dashes at the start of the line:

numpad
| ----

The first time you run numpad, it will create a history.txt file in the currenct directory. You can use the arrow keys to browse your REPL input history while the REPL is running.

To run the REPL after passing in a source file, use the --repl flag:

numpad hello.num --repl

Read the full documentation on Numpad's website