Syntax

A tour of every piece of the May language: literals, control flow, functions, and the pipe operator.

Comments

There are no special comment delimiters. Use whitespace and naming to keep code clear.

Literals

42         // int
3.14       // float
"hello"    // string
[1, 2, 3]  // array
{ k: 1 }   // object

Variables

Declare a variable with a type keyword followed by a name and an initializer:

int score = 100;
string name = "May";
float ratio = 0.5;
array nums = [1, 2, 3];
object user = { name: "Ada", age: 30 };
var anything = 42;

Use var when you do not want to commit to a type. The other keywords double as documentation for what the variable holds.

Operators

Arithmetic

a + b   // add (also concatenates strings)
a - b   // subtract
a * b   // multiply
a / b   // divide
a++     // increment in place

Comparison

a == b
a != b
a < b
a > b
a <= b
a >= b

The pipe operator

The pipe ( | ) feeds the value on its left into the function on its right. It chains transformations without nesting.

"hello world" | upper | print;
// is equivalent to
print(upper("hello world"));

Pipes work with any single-argument function, including ones you write.

Control flow

If / else

if (score >= 90) {
    print("A");
} else {
    print("Not yet");
}

While

int i = 0;
while (i < 5) {
    print(toString(i));
    i++;
}

Use break to exit a loop and continue to skip to the next iteration.

Functions

Functions begin with a return type, a name, parameters with their types, and a body. Use return to send a value back.

int add(int a, int b) {
    return a + b;
}

add(3, 4) | print;

Functions that do not need to return a value can return void:

string greet(string name) {
    return "Hello, " + name;
}

Objects and field access

Objects are key-value collections written with curly braces. Access fields with the arrow operator ->:

object user = { name: "Ada", age: 30 };
user->name | print;
user->age | print;

Field access is also how you reach into the request object returned by read_request:

object req = read_request(client);
print(req->method + " " + req->path);

Arrays

Arrays use square brackets. Use length() to get the size and index with brackets:

array nums = [10, 20, 30];
nums[0] | print;
nums | length | print;

Imports and exports

Pull in standard library modules by name:

import "io";
import "http";
import "html";

Pull in your own files by relative path. Mark anything you want to expose with the export keyword:

// utils.may
export string greet(string name) {
    return "Hello, " + name;
}

// main.may
import "utils.may";
greet("world") | print;

That is the whole language