ion

ion is a multi-purpose, statically-typed programming language with a focus on productivity.

Specification and examples

Hello world

Here is a classic hello world in ion:

import "std/io"

func main() {
	std::io::println("Hello world!")
}

Any ion program starts at the main entry point and then executes linearly.

Variable declaration

The syntax for variable declarations is:

var my_variable: string = "Hello"

The assignment part is optional only if the type is a primitive with a default value:

Type	Default value
string	""
int	0
bool	false
char	'\0'

Types

Along with the 4 primitive types previously cited and custom structs, the built-in types are:

Type	Syntax
array	[]type
map	[key_type]value_type
const ref	&type
mut ref	@type

Var assignment

my_variable = "new text"
my_array[4] = "another value"
my_array[] = "new item in array"
my_ref = @some_var
*my_ref = "new content"

Func declaration

func my_function(param1: Type1, param2: Type2 = "default_value") -> ReturnType {
	...
}

Struct declaration

struct MyStruct {
	field1: Type1,
	field2: Type2
}

Struct init

var my_var: MyStruct = new MyStruct {
	field1: value1,
	field2: value2
}

Func call

var my_return: ReturnType = my_function(arg1, arg2)

Struct field access

std::io::println(my_struct.field1)

If/else if/else

if condition {
	...
} else if other_condition {
	...
} else {
	...
}

While

while condition {
	...
}

For..in

for item in my_array {
	...
}

for char in my_string {
	...
}

Imports

import "relative/path/to/file"

func main {
	relative::path::to::file::my_function()
}

Standard library

Global/built-in

• print(any)
• readln() -> string

std::io

• std::io::println(string)
• std::io::read_int() -> int

std::conv

• std::conv::char_to_int(char) -> int
• std::conv::str_to_int(string) -> int

std::math

• std::math::pow(int, int) -> int

Usage

ion my_source_file.ion

Note: for now, your files have to be placed alongside the executable, as well as the std folder.