Draft:Odin (programming language)

Odin

Paradigms	imperative, procedural
Designed by	Ginger Bill
First appeared	July 7, 2016 (2016-07-07)
Typing discipline	Static, strong, inferred, structural, generic
Platform	x86-64, ARM, WebAssembly
OS	Cross-platform
License	3-clause BSD
Filename extensions	.odin
Website	odin-lang.org
Influenced by
Pascal, C, Go, Oberon-2, Newsqueak, Jai, GLSL

Odin is an imperative, general-purpose, statically typed, distinctly typed, compiled system programming language designed by Ginger Bill.

The language is designed for "high performance, modern systems, and built-in data-oriented data types", supports compile-time parametric polymorphism, runtime reflection, cross-compilation, manual memory management, array programming, and SOA data types.

Example

package main

import "core:fmt"

main :: proc() {
	program := "+ + * 😃 - /"
	accumulator := 0

	for token in program {
		switch token {
		case '+': accumulator += 1
		case '-': accumulator -= 1
		case '*': accumulator *= 2
		case '/': accumulator /= 2
		case '😃': accumulator *= accumulator
		case: // Ignore everything else
		}
	}

	fmt.printf("The program \"%s\" calculates the value %d\n",
	           program, accumulator)
}

Design

Odin is designed as being an alternative for the C programming language on "high performance, modern systems", with features like compile-time parametric polymorphism, array programming, and runtime reflection.

Syntax

Odin's declaration syntax is inspired by Newsqueak and Jai.

// Variable declarations
x : int = 123
x := 123 // Type inference

// Constant value declarations
X :: 123
Y : int : 123

// Function declaration
Z :: proc() {}

Explicit procedure overloading

Odin has procedure overloading, but unlike C++ the overloads have to be specified explicitly.

bool_to_string :: proc(b: bool) -> string {...}
int_to_string  :: proc(i: int)  -> string {...}

// "to_string" is will call either "bool_to_string" or "int_to_string" depending on type.
to_string :: proc{bool_to_string, int_to_string}

Array programming

Odin provides array programming, enabling arithmetics on array elements:

a := [3]f32{ 1, 2, 3 }
b := [3]f32{ 5, 6, 7 }
c := a * b
d := a + b
e := 1 + (c - d) / 2
fmt.printf("%.1f\n", e) // [0.5, 3.0, 6.5]

The language also features "swizzling" of arrays, similar to the operation in shader languages like GLSL.

// Declaring type Vector to be the same as array of 3 f32's.
Vector3 :: [3]f32

// Cross product using swizzle function
cross :: proc(a, b: Vector3) -> Vector3 {
	i := swizzle(a, 1, 2, 0) * swizzle(b, 2, 0, 1)
	j := swizzle(a, 2, 0, 1) * swizzle(b, 1, 2, 0)
	return i - j
}

// Cross product using shorter swizzle notation
cross_shorter :: proc(a, b: Vector3) -> Vector3 {
	i := a.yzx * b.zxy
	j := a.zxy * b.yzx
	return i - j
}

Matrix support

A matrix is a mathematical type built into Odin. It is a regular array of numbers, arranged in rows and columns. Odin's matrix support allows for matrix-array and matrix-matrix operations making it a Level 3 Basic Linear Algebra Subprograming language.

a: matrix[2, 3]f32 // matrix that has 2 rows and 3 columns with an element type of f32
b: matrix[3, 2]f32 // matrix that has 3 rows and 2 columns with an element type of f32
v: [2]f32          // array that has 2 elements with an element type of f32

a = matrix[2, 3]f32{
	1, 9, -13,
	20, 5, -6,
}
b = matrix[3, 2]f32{
	3, 5,
    7, 9,
}
v = [2]f32{2, -4}

m  := a * b // matrix-matrix multiplication
vp := m * v // matrix-array multiplication

The internal representation of a matrix in Odin is stored in column-major format while the matrix literals are written in standard (row-major like) order (e.g. matrix[2, 3]f32 is internally [3][2]f32 (with different a alignment requirement)). Column-major is used in order to utilize (SIMD) vector instructions effectively on modern hardware, if possible.

Comparisons with other languages

The syntax of Odin resembles Go's syntax with many adjustments.

Compared to C, Odin:

• Removes UB from the language
• Removes text-based preprocessing stage
• Introduces strong typing
• Adds array programming and improves runtime reflection
• Has explicit function overloading

Compared to Go, Odin:

• Has manual memory management
• Does not have interfaces

Notable software built with Odin

• EmberGen, a real-time volumetric fluid simulator by JangaFX.

See also

• Pascal
• C
• Go
• Newsqueak
• Array_programming
• Basic Linear Algebra Subprograms (BLAS)
• SIMD

External links

• Official website
• Odin at Handmade Network