Loopily

Loopily is a lightweight, QBasic-inspired scripting language built with Node.js. It is designed for learning how interpreters work while staying simple, readable, and extensible.

Features

• Variables using LET
• Output using SAY
• Conditional statements (IF / ELSE)
• Loops (LOOP)
• Functions (FUN)
• Function calls with parameters
• Basic arithmetic and comparison operators
• Runtime error reporting

Installation

Clone the repository:

Make sure Node.js is installed (recommended v16 or later).

Running Loopily

Run a .loop file:

loopily program.loop

Run inline code:

loopily -e "SAY \"Hello Loopily\""

Example Program

SAY "Hello Loopily"

LET name = "Ei Ei Htwe"
SAY name

LOOP 3
SAY "Loop running"
END

Language Syntax

Variables

LET x = 10

Output

SAY "Hello"
SAY x

Loop

LOOP 5
SAY "Running"
END

If / Else

IF x > 5 THEN
SAY "Big number"
ELSE
SAY "Small number"
END

Functions

FUN greet name
SAY "Hello"
SAY name
END

greet "Loopily"

Project Structure

loopily/
├── lexer.js
├── parser.js
├── evaluator.js
├── loopily.js
├── filecreate.js
├── package.json
├── program.loop
└── README.md

Roadmap

• Add real scope system (local variables)
• Add return values from functions
• Improve function call syntax
• Add REPL mode
• Add standard library functions
• Improve error recovery
• Publish as npm package

Notes

Loopily is a learning project focused on understanding:

• Parsing and tokenization
• Abstract Syntax Trees (AST)
• Interpreter design
• Execution flow and scope handling

It is not intended for production use at this stage.

License

MIT License