Metamaya

Metamaya is a declarative programming language with minimal syntax.

The language is currently rather simple, but more exciting features are on the roadmap:

• lazy evaluation
• pattern matching
• cyclic dependency detection
• optional typing...

Installation

In node.js:

npm install metamaya

Usage

In example.mm:

a = b.x;
b = {
    x = 1;
}

In Javascript:

var mm = require("metamaya");
var example = mm.require("./example.mm");
console.log(mm.eval(example.a));

Output:

1

Alternatively, you can compile a string directly.

var mod = mm.compile("x = 3*3");
console.log(mm.eval(mod.x));

Quick tour

Names are statically scoped in metamaya programs. As reassignment is not allowed, a name is simply defined by assigning a value to it.

a = b.c.y; // 1
b = {
    x = 1;
    c = { y = x; }  // x comes from the enclosing scope
}

You can do the usual arithmetics. As you have probably noticed, names can be accessed before the place of definition.

a = (x + y) * (x - y); // -5
x = 2;
y = 3;

Metamaya operators are simply Javascript operators, so you can guess what happens when two strings are added up.

a = "meta";
b = "maya";
mm = a + b; // "metamaya"

The Javascript global context can be accessed from metamaya code.

a = Number("2"); // 2

You can easily define your own functions too.

sqr(x) = x * x
a = sqr(3); // 9

That's all for now. Please note that metamaya is in a very early phase, so anything may change the next week.