The Umpteen Programming Language

This repository provides the reference implementation for the Umpteen Programming Language, bootstrapped from Rust. Umpteen is currently in development and frequent breaking changes are expected until v1.0.x

As such, Umpteen is not yet recommended for use in production

Syntax

Comments

Write a line comment with # or a block comment with opening and closing ###

# This is a line comment

###
This is a block comment
Continued over multiple
lines
###

Variables

Create mutable or immutable* bindings with var and let respectively

var x = 10; # x is mutable
let y = 20; # y is immutable
x = 0; # OK ✅
y = 0; # ERROR 🚫

*NOTE: Immutable bindings are not yet implemented

Scope

# Global Scope

let a = 10;
print(a); # 10
{
  # Block-scope
  print(a); # 10

  let a = 20;
  print(a); # 20
}

print(a); # 10

Shadowing*

Immutable bindings support shadowing within the same scope

let a = 10; # OK ✅
let a = 20: # OK ✅
a = 30; # ERROR 🚫

*NOTE: Shadowing within the same scope is not yet implemented

Mutable bindings can be reassigned, however they are not permitted to be shadowed within the same scope. Conversely, shadowing is permitted within a narrower scope

var a = 10; # OK ✅
{
  var a = 20; # OK ✅
}
a = 30; # OK ✅
var a = 40 # ERROR 🚫

Conditionals

Test an expression with the if keyword

if true {
  print("This code prints!"); # ✅
}

if false {
  print("This code is unreachable"); # ⛔
}

As well as else and else if

let something = false;
let somethingElse = false;

if something {
  print("Something!");
} else if somethingElse {
  print("Something else!");
} else {
  print("Neither!");
}

Loops

Execute statements multiple times with the loop keyword. Use break to exit early from the loop body, or continue to halt execution of the current iteration and skip to the next one

var i = 0;
loop {
  print(i);
  i += 1;

  if i > 10 {
    break;
  }
}

Functions

Declare a function with the fnc keyword. Parameters require type annotations. Annotations for return types are required, unless the function returns Empty

fnc fib(n: Number) -> Number {
  if n <= 1 {
    return n;
  }

  return fib(n - 2) + fib(n - 1);
}

Data Types*

• Empty: No value
• Boolean: true or false
• Number: IEEE 754 double-precision floating point representation of numerics
• String: A series of characters
• Object: Compound data types passed by reference instead of by value
  • Fnc: Function type representing a discrete collection of executable instructions
    NOTE: User-defined functions are not yet implemented
  • List: Dynamic Array type, representing a one-dimensional dynamically resizeable numerically indexed collection

*NOTE: The full specification for Umpteen's type system is not yet defined, definition of all types is subject to change prior to v1.0.x

---

WARNING: Umpteen is still in active development and frequent breaking changes are expected prior to v1.0.x. Not yet recommended for production use!