OOLANG

OOLANG is an esoteric stack-based programming language where all instructions/commands are differnet unicode O characters

Usage

oorun, a command line runner, is available on crates.io, and can be installed with Cargo:

cargo install OOLANG

OOLANG files end in .oo, and consist of a number of commands specified each by a single unicode glyph. Any other character is ignored. Comments are supported using the # character, which comments out up to the end of the line.

oorun file.oo will execute your OOLANG program, reading from stdin and printing any output to the console. The return value is also shown. For example,

$ echo -n "Hello, World!" | oorun echo.oo
Running OOLANG file: echo.oo...
Output: Hello, World!
Return value: 13

Language Specification

OOLANG emulates a stack machine, not dissimilar to how the JVM or Python's bytecode interpreter works.

The virtual machine consists of a stack of bytes, and 256 bytes of addressable memory. A valid OOLANG program may consist of any combination of the the following 10 commands:

Command	Unicode Character Name	Command Name	Description
O	Latin Capital Letter O	PUSH	Push the value 1 onto the top of the stack.
0	Digit Zero	POP	Pop the value from the top of the stack, discarding it.
Ǿ	Latin Capital Letter O with Stroke and Acute	INC	Increment the value on the top of the stack.
Ꮻ	Cherokee Letter Wi	DEC	Decrement the value on the top of the stack.
⭕	Heavy Large Circle	ADD	Pop the top two stack values, add them, push the result.
𐍉	Gothic Letter Othal	JNZ	Jump to the address at the top of the stack, if the 2nd-top value is non-zero.
Ꝍ	Latin Capital Letter O with Loop	JZ	Jump to the address at the top of the stack, if the 2nd-top value is zero.
◎	Bullseye	LOAD	Pop a memory address from the stack, and push the value at that address.
◯	Large Circle	STORE	Pop the top two values from the stack, storing the 2nd value at the address specified by the 1st.
⒪	Parenthesized Latin Small Letter O	READ	Read the next byte from stdin, pushing it to the top of the stack, or 0 if stdin is empty.
ₒ	Latin Subscript Small Letter O	WRITE	Pop from the stack and write the value to stdout as an ascii character.

The return value of an OOLANG program is the value at the top of the stack when the program exits.

Architecture

The language and interpreter are written in Rust. The compiled binary executable acts as a command line program, but the interpreter crate also exposes a public API. When compiled to webassembly, this API is used to provide functionality for the Web IDE within the browser.