Quan-Lang

Quan-Lang is a simple interpreted programming language implemented in Go. It is designed for learning and experimenting with language design, interpreters, and compilers. Quan-Lang features a custom lexer, parser, and interpreter, and supports variables, functions, arithmetic operations, and conditionals.

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Table of Contents

• Features
• Project Structure
• Installation
• Usage
• Example
• Lexer Example
• Contributing
• License

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Features

• Lexer: Converts source code into tokens.
• Parser: Builds an abstract syntax tree (AST) from tokens.
• Interpreter: Evaluates the AST and executes code.
• Variables: Assignment and usage.
• Functions: User-defined functions with parameters and return values.
• Conditionals: if/else statements.
• Arithmetic: Supports +, -, *, /, %, ^, and comparison operators.
• Block Scoping: Functions and conditionals have their own scope.
• Objects: Object literals and property access.
• Arrays: Array literals, indexing, and array utility functions.
• Floats: Native support for floating-point numbers and arithmetic.
• EmptyReturn: Return without value from a function.
• Null: Null value.
• Template Strings: JS-like template strings with ${} expressions.
• Debug Options: Built-in debug utilities and options for tracing/interpreter output.
• Extensible: Modular design for easy extension.
• WebAssembly: Support WebAssembly, this engine can run from browser
• New APIs: Support fetch(), toJson(), toMap()
• Parser: int(), float(), string(), bool()

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Project Structure

quan-lang/
├── array/         # Array utilities
├── debug/         # Debug utilities
├── env/           # Environment (variable/function scope)
├── expression/    # AST node definitions
├── helper/        # Helper functions
├── intepreter/    # Interpreter logic
├── lexer/         # Lexer (tokenizer)
├── paraser/       # Parser (AST builder)
├── quan-lang/     # Language entry point
├── token/         # Token definitions
├── go.mod
├── main.go
├── readme.md
├── sample-program.quan

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Installation

1. Clone the repository:

   git clone https://github.com/yourusername/quan-lang.git
   cd quan-lang

2. Install Go (if not already installed): Download Go

3. Run the interpreter:

   go run main.go

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Usage

You can write Quan-Lang code as a string and execute it using the provided API, or run a .quan script file.

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Example

program := `
    fn calculateInterest(principal, rate, time) {
        return principal * rate * time / 100;
    }
    interest = calculateInterest(loanAmount, 3, 1);
`

env, _ := lang.Execuate(program, &env.Env{
    Vars: map[string]interface{}{"loanAmount": 100000},
})

fmt.Printf("Interest: %f\n", env.Vars["interest"])

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Array, Float, and Debug Example

program := `
    arr = [1, 2, 3.5, 4];
    sum = 0.0;
    for (i = 0; i < len(arr); i = i + 1) {
        sum = sum + arr[i];
    }
    debug("Sum of array:", sum);
`
env, _ := lang.Execuate(program, &env.Env{
    Debug: true, // Enable debug output
})

fmt.Printf("Sum: %f\n", env.Vars["sum"])

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Lexer Example

The lexer scans the input string and produces a slice of tokens.
Here is a simplified excerpt from lexer/lexer.go:

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Contributing

Contributions are welcome! Please open issues or submit pull requests for improvements and bug fixes.

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License

This project is licensed under the MIT License.

Builds

Buid binary

go build main.go 

WebAssembliy

GOOS=js GOARCH=wasm go build -o qlang.wasm main.go     

Maintainer and Creator

Name: jianshangquan Github: Account