Minecraft Function Language (Not affiliated with Mojang, hobby project)

Minecraft Function Lang, a basic scripting language for minecraft

This project isn't intended to be used anywhere, just a hobby project to create a scripting language with more functionality than the .mcfunction format, which is literally just a command list with comment support

Note: The parser uses '$' to differentiate between regular command lines and statements/expressions

PS, do not expect this to be an ultra-fast implementation of a scripting language, this is just a hobby project that works with an interpreter

TODO

1. Lexer
2. Parser
3. If statements
4. Functions
5. Loops ($for and $while)
6. Operators
   1. add (+)
   2. sub (-)
   3. div (/)
   4. mul (*)
   5. pow (x**y)
   6. or (|)
   7. and (&)
   8. xor (^)
   9. negate (!)
   10. bitwise negate (~)
7. String templating ($bindingIdentifier and ${expression}) for both commands and quoted strings
8. Accessing properties on objects and calling methods
9. PaperMC support (Currently just a parser and interpreter)

Features

Completely backwards compatible with .mcfunction files

Support for all operators found in hava

$let x = 10
$let y = 20

$print(-x)
$print(+x)
$print(++x)
$print(--x)
$print(x--)
$print(x++)
$print(x + y)
$print(x - y)
$print(x * y)
$print(x / y)
$print(x | y)
$print(x & y)
$print(x % y)
$print(x << y)
$print(x < y)
$print(x > y)
$print(x >= y)
$print(x <= y)
$print(x <<< y)
$print(x >> y)
$print(x >>> y)

String and command templating

$const const_value = 12
$const other_const = 13

# Final result will be 'tellraw @a {"text":"25"}' 
tellraw @a {"text":"${const_value + other_const}"}

# Final result will be "const_value+other_const = 25"
$const const_string = "const_value+other_const = ${const_value + other_const}"

Run commands alongside statements and expressions

$const MAX_TICKS = 200

$global-let tickCount = 0
$tickCount++

$if (tickCount >= MAX_TICKS) {
  tellraw @a {"text":"Timer has ended, kicking all players out of arena","color":"green","bold":true}
  teleport @a[x=0,y=75,z=0,distance=..20] 51.5 80 51.5
}

schedule("1t")

for, while and do {} while () loops

#FizzBuzz

$let output = ""

$for ($let i = 0; i < 100; i++) {
  $if (i % 3 == 0) {
    $output += "Fizz"
  }
  
  $if (i % 5 == 0) {
    $output += "Buzz"
  }
  
  $if (output == "") {
    $output = i
  }
  
  tellraw @a "${output}"
  $output = ""
}

Built in values and functions

print(message...)

Prints an array of messages that are joined together to the console

Example:

$print("Hello, world!")

systemTimeMillis

Numeric value for the system time in milliseconds, wrapper for Java's System.currentTimeMillis()

Example:

# Gets the system time at this moment
$time = systemTimeMillis

scriptTime

Seconds since the script was activated, floating point number.

Example:

# Gets the script time at this moment
$time = scriptTime

Using through Java

import me.jules.mcfl.*;
import me.jules.mcfl.interpreter.*;
import me.jules.mcfl.ast.*;

// ...

Path filePath = /* Get the path of the file you want to load */;

// Parse file
FunctionFile file = FunctionLang.parse(filePath);

// Create file scope and execution context
Scope scope = FunctionLang.defineStandardScope();
ExecContext ctx = new ExecContext();

// This will take a string command as input and 'execute' it
ctx.setExecutor(command -> {
  System.out.println("command=" + command);
  return 0;
});

// Evaluate file
try {
  file.execute(ctx, scope);
} catch (EvaluationError err) {
  err.printStackTrace();
}