jvns/examples.md

## examples.md

      
    Raw
  

              examples.md
            
          
    Strings

The std::str documentation is also quite good.
// Create a string from a literal
let hello: &'static str = "Hello!";
let hello2: &str = "Hello!";

// Create an owned string
let owned_hello: ~str = ~"Hello!";

// Create a managed string
let managed_hello: @str = @"Hello!";

// Mutable owned string
// There are no mutable string slices
let mut buf : ~str = ~"Hello";
buf.push_str(", world!");

// Convert a string to its representation as bytes
// It's impossible to convert back
let hello_as_bytes: &[u8] = "hello!".as_bytes();

// Create a &[u8] using a byte literal
let hello_as_bytes2: &[u8] = bytes!("hello");

// Take a slice of a string
let hello_slice: &str = hello.slice(0, 3);
let owned_hello_slice: &str = owned_hello.slice(0, 3);
Vectors

See also std::vec
// Create a fixed size vector
let x : [uint, ..10] = [5, ..10]
// [5, 5, 5, 5, 5, 5, 5, 5, 5, 5]

// There are no fixed size strings because that wouldn't make sense.

// Create a variable size owned vector
let mut numbers : ~[uint]= ~[0, 1, 2];

// Create a variable size
let mut numbers : &[uint]= &[0, 1, 2];

// Do some other thing
let mut xs = [0, ..10]; 
for (i, r) in range(0, 10).zip(xs.mut_iter()) { *r = i; } 
xs;
// [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Making a mutable vector

let mut numbers: [int] = [0,1,2]; 
numbers[1] = 2; 
numbers; /// [0, 2, 2]

let mut numbers: &[int] = [0,1,2];
numbers[1] = 2; // error: numbers is mutable, not the vector it points to
Functions

For an explanation of function types, see Fn types in Rust
Basically fn() is the only function type you want. *fn() is a type, but it doesn't make sense to use it, and ~fn(), &fn(), @fn() are not types.
For a function using the C calling convention, use extern "C" fn(). The part in quotes signifies the calling convention.
Structs

Make a packed struct using:
#[packed]
struct IDTPointer {
    limit: u16,
    base: u32
}
Exporting things & FFI

Rust FFI tutorial

main is always exported
You can't export global variables.
You can export other functions, but only in libraries

For a function to be exported, it should look like
#[no_mangle]
pub fn x() {
}
and then you need to compile foo.rs with the --lib flag