Feeny Language

Feeny is a dynamic programming language that runs on a self-constructed virtual machine. This implementation includes a bytecode compiler and interpreter, demonstrating core concepts of language implementation.

Features

• Dynamic typing system with primitive types and objects
• Object-oriented programming support with inheritance
• Garbage collection
• NaN boxing optimization for efficient value representation
• Python-like indentation-based syntax

Quick Start

Installation

# Clone the repository
git clone https://github.com/HaleOIC/FeenyLanguage.git
cd feeny

# Build the interpreter
make compile

After running the above commands, an executable file is located in ./bin directory.

Running Your First Feeny Program

1. Create a file hello.feeny:

   printf("Hello, World!\n")
   

2. Run it, there are two versions of interpretation, one is ast-level interpretation with flag -a, the other is bytecode-level interpretation with flag -f:

   ./bin/cfeeny -a hello.feeny # ast interpreter
   ./bin/cfeeny -f hello.feeny # bytecode compiler on vm

Basic Syntax

1. Variables and Functions

    var x = 42          ;Global variable
    defn add(a, b):     ; Function definition
        a + b
   

2. Objects and Methods

    object:
        var x = 10
        var y = 20
        method sum():
            this.x + this.y
   

3. Control Flow

    ; If statement
    if x < 10:
        printf("Less than 10\n")
    else:
        printf("Greater or equal to 10\n")
   
    ; While loop
    while i < 10:
        printf("i = ~\n", i)
        i = i + 1
   

More syntax can be found in ./docs

Example Code

defn three():
    3

defn hello(i):
    printf("Hello ~ ", i)

defn world(j, k):
    printf("World ~ ~\n", j, k)

defn main():
    var i = three()
    hello(i)
    i = 10
    world(4, i)

main()

Test

cd test
./run_test_bytecode_compiler.sh
./run_test_ast_interpreter.sh