response

type struct Name { ... }
type enum Name { ... }
type trait Name { ... }
type union Name { ... }

Begins a type declaration; the keyword that follows says which kind. On its own, type Name = Existing; declares an alias.

type struct Name {
    field: Type;
    method(&this) -> Ret { ... }
}

A value type with named fields and optional methods. Structs live on the stack and are passed by value. Fields are public by default and may carry = default values; methods take their receiver as &this, mut &this, or this.

type struct Response {
    status: StatusCode;
    version: String;
    headers: Headers;
    body: Array<u8>;
}

HTTP response.

type struct String<A = GlobalAlloc> {
    buffer: RawBuffer<u8, A>;
    length: u64;
}

String: owned, heap-allocated, length-typed UTF-8.

type struct Headers {
    inner: HashMap<String, String>;
}

HTTP headers: case-insensitive name/value map.

type struct Array<T, A = GlobalAlloc> where A: Allocator {
    ptr: T*;
    length: i64;
    capacity: i64;
    alloc: A;
}

Array<T, A>: growable, heap-backed, contiguous sequence.

primitive u8

8-bit unsigned integer.

static name(param: Type) -> Ret { ... }

A method that belongs to the type rather than an instance, called as Type::name(..). For structs, static new(..) returning a struct literal is the idiomatic constructor.

type struct Response {
    status: StatusCode;
    version: String;
    headers: Headers;
    body: Array<u8>;
}

HTTP response.

static Response::text(status: StatusCode, body: Str) -> Response

Convenience: Response::text(StatusCode::ok(), "hello") with Content-Type text/plain; charset=utf-8 and Content-Length set.

type struct Str {
    bytes: u8*;
    length: u64;
}

Str: a borrowed UTF-8 string slice.

static Response::json(status: StatusCode, body: Array<u8>) -> Response

Convenience for JSON: sets Content-Type and Content-Length. The caller is responsible for producing valid JSON; no validation is performed.

Response::set_body(mut &this, body: Array<u8>) -> void

Install body and set Content-Length to match. Ownership of the array transfers to the response.

mut &this
mut &Type

An exclusive, mutating borrow. As a receiver, mut &this lets the method modify the fields - and callers can see that from the signature alone. As a parameter type, mut &T lets the callee mutate through the reference while the caller keeps ownership.

&this
mut &this
this

The receiver of a method. Its first parameter declares how the method takes it: &this borrows read-only, mut &this borrows exclusively, and this / mut this move the value in and consume it. In the body, this.field reaches the members.

primitive void

No value; only valid as a return type.

static Response::from_status_line(line: Str) -> Result<Response, IoError>

Parse a Status-Line (HTTP/x.y SP code SP reason, no CRLF) into a response with empty headers and no body. A missing code or a non-numeric one is InvalidData. The reason phrase is advisory and discarded; the code is what callers dispatch on.

type enum Result<T, E> {
    Ok(T);
    Err(E);
}

Result: a value that may be an error.

Response::encode_into(&this, out: Array<u8>*) -> Result<(), IoError>

Append the whole message — status line, headers, blank line, body — to out, normally the connection's pending() buffer.

primitive ()

The unit type: a value that carries no information, and the empty tuple. Distinct from void, which is the absence of a value - Result<(), E> succeeds with nothing to return. 0 bytes.

function name<T>(param: Type) -> Ret { ... }

Declares a function. Parameters are written name: Type and are never inferred; the return type follows -> and defaults to void. Declaration order does not matter: every signature is collected before any body is checked, so functions may call each other freely and recurse.

type struct Request {
    method: Method;
    path: String;
    version: String;
    headers: Headers;
    body: Array<u8>;
    params: HashMap<String, String>;
}

HTTP request.

return value;

Leaves the current function with the given value. A function whose return type is not void must return one; a bare return; is for void. In an async function it completes the future with the value.

static Response::text(status: StatusCode, body: Str) -> Response

Convenience: Response::text(StatusCode::ok(), "hello") with Content-Type text/plain; charset=utf-8 and Content-Length set.

static Str::new(text: string) -> Str

Construct from a NUL-terminated C-style string literal. The caller certifies that text is valid UTF-8 and outlives this view. The NUL terminator is not included in the view.

const NAME: Type = value;

At module level, a true compile-time constant, conventionally SCREAMING_SNAKE_CASE. (mut at module level declares mutable global state instead.)

primitive u64

64-bit unsigned integer.

import a::b;
import a::b::{ X, Y };
import a::b as c;
import a::b::*;

Brings a module, or selected items from it, into scope. One path per declaration: use the brace form for several items, as to alias, and * for everything public (prefer the brace form; wildcards invite name collisions).

namespace std;

std: the Cryo standard library.

namespace std::net;

net: network primitives + HTTP.

namespace std::net::http;

http: HTTP/1.1 with keep-alive.

namespace std::net::http::response;

HTTP response.

static Response::json(status: StatusCode, body: Array<u8>) -> Response

Convenience for JSON: sets Content-Type and Content-Length. The caller is responsible for producing valid JSON; no validation is performed.

Response::set_body(mut &this, body: Array<u8>) -> void

Install body and set Content-Length to match. Ownership of the array transfers to the response.

Response::encode_into(&this, out: Array<u8>*) -> Result<(), IoError>

Append the whole message — status line, headers, blank line, body — to out, normally the connection's pending() buffer.

static Response::from_status_line(line: Str) -> Result<Response, IoError>

Parse a Status-Line (HTTP/x.y SP code SP reason, no CRLF) into a response with empty headers and no body. A missing code or a non-numeric one is InvalidData. The reason phrase is advisory and discarded; the code is what callers dispatch on.

implement struct Name { ... }
implement trait Trait for Type { ... }
implement u64 { ... }

Adds methods to a type outside its declaration. implement struct T (or enum, or a bare primitive) opens an inherent block; implement trait Tr for T supplies a trait's methods for one type. Resolution is at compile time - no dynamic dispatch.

implement trait Trait for Type { ... }

Introduces a trait implementation: the block supplies, for one concrete type, the method bodies the trait requires.

type trait Drop {
    drop(mut &this) -> void;
}

Drop: explicit destructor.

implement trait Trait for Type { ... }

Names the type a trait implementation is for. The block that follows supplies the bodies the trait requires.