Mutable and Immutable 

  const pi: f64 = 3.14159;    -- immutable, must be initialized
var count: i32 = 0;          -- mutable

count := count + 1;          -- reassignment uses :=
count += 1;                  -- compound assignment

:= for reassignment, = for initialization and equality comparison. This comes from Pascal. = in expression position is always equality — there is no == in Violet.

  if count = 5 {               -- = means equality here
    debug.print("five!\n");
}

Type Inference 

  var x = 42;                  -- inferred as i32
var s = "hello";             -- inferred as []const u8
var f = 3.14;                -- inferred as f64

Constants

Constants are compile-time values. They can be used anywhere a comptime value is expected:

  const MAX_SIZE: usize = 1024;
const APP_NAME: []const u8 = "myapp";
const VERSION: u32 = 1;

Multiple Bindings 

  -- destructuring from anonymous struct
var .{ x, y } = getPoint();

-- multiple assignment
var a: i32 = 1;
var b: i32 = 2;
a := b;
b := a;   -- this doesn't swap! a is already 2

To swap:

  var tmp = a;
a := b;
b := tmp;