Variables and Types

RUDRA is statically typed. Bindings are immutable by default.

Bindings

Use let for an immutable binding and let mut for a mutable one.

fn main() -> int {
    let name = "RUDRA";
    let mut count = 3;
    count = count + 1;
    print(name + "\n");
    print(to_str(count) + "\n");
    return 0;
}
return main();

Type annotations

You can annotate a binding with its type. print accepts only a str and adds no newline, so convert numbers with to_str.

fn main() -> int {
    let title: str = "Systems language";
    let answer: int = 42;
    let ratio: float = 3.5;
    let ok: bool = true;
    print(title + "\n");
    print(to_str(answer) + "\n");
    if ok {
        print("ok\n");
    }
    return 0;
}
return main();

Core types

Type	Description	Example
`int`	Integer	`42`
`float`	Floating-point number	`3.14`
`bool`	Boolean	`true`, `false`
`str`	String	`"text"`

Lists

RUDRA has no fixed-size array literals. Use list[int]: create it with list_new(), add with push, read with get (indexed from zero) and count with list_len. Lists are capped at 512 elements, and an out-of-range access aborts the program (exit 134).

fn main() -> int {
    let nums = list_new();
    push(nums, 10);
    push(nums, 20);
    push(nums, 30);
    print(to_str(get(nums, 0)) + "\n");
    print(to_str(get(nums, 2)) + "\n");
    print(to_str(list_len(nums)) + "\n");
    return 0;
}
return main();

Strings

Strings concatenate with +; str_len returns a string length and substr(s, start, length) extracts part of a string.

fn main() -> int {
    let greeting = "Namaste, " + "RUDRA";
    print(greeting + "\n");
    print(to_str(str_len(greeting)) + "\n");
    print(substr(greeting, 0, 7) + "\n");
    return 0;
}
return main();