Gate

A dynamically typed interpreted language written in Rust.

Usage

To run a program, pass it as an argument to the Gate interpreter.

$ gate hello_world.gate
Hello world!

There's also a REPL available.

$ gate -i
> 5 + 6.6
Number(11.6)

Syntax

Types

Gate supports basic types such as nil, booleans, numbers and strings.

> nil
Nil
> false
Boolean(false)
> true
Boolean(true)
> 3
Number(3)
> -2.3
Number(-2.3)
> "foo bar"
Str("foo bar")

Variables

Variables are assigned using the = operator.

> x = 32
Number(32)

Since variable assignment is an expression, they can be chained together.

> a = b = c = 2
Number(2)
> a
Number(2)
> b
Number(2)
> c
Number(2)

Control flow

Loops and if statements form the building blocks of control flow in Gate. Note that they too are expressions.

> if x == 12 { "It's 12" } else { "Definitely not 12" }
Str("Definitely not 12")
> while x < 3 { x = x + 1 }
Number(3)

Blocks

Blocks allow you to evaluate multiple expressions. They evaluate to the value of the last expression. This allows you to compose multiple expressions in interesting ways.

> { 0 true "foo" }
Str("foo")
> x = { b = 1   if b == 1 "it's 1" else "not 1"}
Str("it\'s 1")