headers

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

HTTP headers: case-insensitive name/value map.

type struct HashMap<K, V, A = GlobalAlloc> where A: Allocator {
    buckets: Entry<K, V>**;
    bucket_count: u64;
    length: u64;
    alloc: A;
    seed: u64;
}

HashMap<K, V, A>: key-value map with amortized O(1) operations.

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

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

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

HTTP headers: case-insensitive name/value map.

&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 u64

64-bit unsigned integer.

primitive boolean

true / false. Not interchangeable with integers. 1 byte.

Headers::insert(mut &this, name: Str, value: Str) -> void

Insert or replace. Name is normalized to lowercase; CR/LF bytes are stripped from both name and value before storing. Ownership of both values transfers to the headers map.

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.

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

Str: a borrowed UTF-8 string slice.

primitive void

No value; only valid as a return type.

Headers::get(&this, name: Str) -> Option<String>

Case-insensitive lookup. Returns a deep-cloned owned copy of the stored value (header values are small, so copy-on-read is cheap), so the caller owns it independently of the map and must drop it.

type enum Option<T> {
    Some(T);
    None;
}

Option: a value that may be absent.

Headers::parse_line(mut &this, line: Str) -> boolean

Parse a single Name: Value header line (no CRLF). Used by the request parser. Returns None on malformed input; the caller turns that into a 400.

Headers::content_length(&this) -> Result<Option<u64>, IoError>

Content-Length as a number. Ok(None) means the header is absent, which for this parser means "no body".

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

Result: a value that may be an error.

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

Append every stored header to out as HTTP/1.1 field lines, name: value\r\n per entry. The caller appends the trailing blank-line CRLF that separates headers from the message body.

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.

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.

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::headers;

HTTP headers: case-insensitive name/value map.

Headers::get(&this, name: Str) -> Option<String>

Case-insensitive lookup. Returns a deep-cloned owned copy of the stored value (header values are small, so copy-on-read is cheap), so the caller owns it independently of the map and must drop it.

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

Append every stored header to out as HTTP/1.1 field lines, name: value\r\n per entry. The caller appends the trailing blank-line CRLF that separates headers from the message body.

Headers::parse_line(mut &this, line: Str) -> boolean

Parse a single Name: Value header line (no CRLF). Used by the request parser. Returns None on malformed input; the caller turns that into a 400.

false

The boolean literal. Booleans are a distinct 1-byte type, not interchangeable with integers; if and while conditions must be boolean.

Headers::content_length(&this) -> Result<Option<u64>, IoError>

Content-Length as a number. Ok(None) means the header is absent, which for this parser means "no body".

Headers::insert(mut &this, name: Str, value: Str) -> void

Insert or replace. Name is normalized to lowercase; CR/LF bytes are stripped from both name and value before storing. Ownership of both values transfers to the headers map.

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.