tau

README

τ

Tau is a dinamically-typed open source programming language designed to be minimal, fast and efficient.

Installation

In order to install Tau, you'll need Go.

Once done, running the following command will successfully install the tau interpreter:

go install github.com/NicoNex/tau@latest

You can try it out in the terminal by simply running $ tau, alternatively to take advantage of the builtin virtual machine and gain a lot of performance run it with $ tau -vm. The flag -vm works when executing files too. For additional info run $ tau --help.

Syntax

Hello World

We all start from here...

println("Hello World")

Examples

File

As every interpreter Tau supports files either by passing the path to the interpreter or by using the shabang.

# helloworld.tau

println("hello world")

$ tau helloworld.tau
hello world

if-else blocks

if 1 > 0 {
	println("yes")
} else {
	println("no")
}

myVar = 10

if myVar > 10 {
	println("more than 10")
} else if myVar == 10 {
	println("it's exactly 10")
} else {
	println(myVar)
}

Declaring a function

loop = fn(times, function) {
	if times != 0 {
		function()
		loop(times-1, function)
	}
}

loop(5, fn() { println("Hello World") })

Noteworthy features

The return value can be implicit:

add = fn(x, y) { x + y }
sum = add(9, 1)
println(sum)
10

Also you can inline the if expressions:

a = 0
b = 1

minimum = if a < b { a } else { b }

The semicolon character ; is implicit on a newline but can be used to separate multiple expressions on a single line.

printData = fn(a, b, c) { println(a); println(b); println(c) }

Functions are first-class and treated as any other data type.

get_minumum = fn(a, b) {
	if a < b {
		return a
	}
	b
}

var1 = 1
var2 = 2

min = get_minimum(var1, var2)
println(min)

>>> 1

REPL

Tau also supports REPL:

>>> add = fn(a, b) { a + b }
>>> string(add)
fn(a, b) { (a + b) }
>>> string(21)
21
>>> recursive_loop = fn(n, func) { if n != 0 { func(n); recursive_loop(n-1, func) } }
>>> recursive_loop(10, fn(n) { println("hello", n) })
hello 10
hello 9
hello 8
hello 7
hello 6
hello 5
hello 4
hello 3
hello 2
hello 1

Data types

Tau is a dynamically-typed programming language and it supports the following primitive types:

Integer

my_var = 10

Float

my_var = 2.5

String

str = "My string here"

Boolean

t = true
f = false

Function

pow = fn(base, exponent) {
	if exponent > 0 {
		return base * pow(base, exponent-1)
	}
	1 # You could optionally write 'return 1', but in this case the return is implicit.
}

List

empty = []
stuff = ["Hello World", 1, 2, 3, true]

Map

empty = {}
stuff = {"Hello": "World", 123: true}

Loop

for i = 0; i < 10; ++i {
	println("hello world", i)
}

lst = [0, 1, 2, 3, 4]

println(lst)
for len(lst) > 0 {
	println(lst = tail(lst))
}

Objects

obj = new()
obj.value1 = 123
obj.value2 = 456

obj.sum_values = fn() {
	obj.value1 + obj.value2
}

obj.child = new()
obj.child.value = obj.sum_values()

Recommended usage

newdog = fn(name, age) {
	dog = new()

	dog.name = name
	dog.age = age

	dog.humanage = fn() {
		dog.age * 7
	}

	return dog
}

snuffles = newdog("Snuffles", 8)
println(snuffles.humanage())

>>> 56