Luederlang v0.0.1

About:

Luederlang is an interpreted language written in Go. Largely inspired by Thorsten Ball's implementation with key changes. Incredibly minimal to fit the hard deadline of the school semester starting. I like naming things after myself, and Luederlang was too good of a name to pass up.

Specs

• Lexer (A5 Military Grade Wagyu)
• Parser (Top Down Operator Precedence / Pratt Parser)
• Evaluator (Treewalking Evaluator)

Features

• C like sytax
• Integers, Booleans, Floats, String literals
• Comments
• Upcasting infix expressions based on operator
• First class and higher-order functions
• Builtin Functions (print, len, help)
• REPL

Missing Features

• Arrays
• Maps
• Loops

Examples

Fizzbuzz without loops and without else-if's:

// ryan.lueder
// A little verbose: we dont have loops but we have recursion
let fizzbuzz = fun(i, n) {
    if (i > n) {
        print("\n");
        return 0;
    }

    // A little verbose: we don't have else-ifs
    if (i % 3 == 0) { print("fizz"); }
    if (i % 5 == 0) { print("buzz"); }
    if (i % 3 != 0 && i % 5 != 0) { print(i); }
    print(" ");

    fizzbuzz(i + 1, n);
}

fizzbuzz(1, 30);

~/ go run main.go ryan.lueder
1 2 fizz 4 buzz fizz 7 8 fizz buzz 11 fizz 13 14 fizzbuzz 16 17 fizz 19 buzz fizz 22 23 fizz buzz 26 fizz 28 29 fizzbuzz

Note that ryan.lueder is the entry point for Luederlang files. This is not enforced by the interpreter but IS industry standard and IS largely believed to be best code style.

Fixed modulus division:

-3 % 5 // => 2, not -3 like in C or Golang

Higher order functions:

// ryan.lueder
// This is the "Hello, World!" program equivalent in Luederlang
let messageUser = fun(msg) {
    return fun(user) {
        msg + " " + user // return not required
    }
}

let helloUser = messageUser("Hello")
print(helloUser("Ryan"))

~/ go run main.go ryan.lueder
Hello Ryan

Typing:

float x = 7.8 // ok
let x = 7.8   // ok

REPL:

~/ go run main.go
type help() for help
>> 5 + 55.5
60.5
>>