Types

Mach ships a small set of compiler-seeded primitive types plus a uniform grammar for building pointers, arrays, and function types out of them. There are no compiler-known aliases: names like bool, usize, and str are stdlib defs.

Primitive scalars

Eleven names make up the complete set of primitive types the compiler seeds. Everything else is built on top of them.

SIMD vectors planned

The planned design extends the primitive numeric types into vectors by appending x<count>.

f32x4           # 4 lanes of f32
i32x8           # 8 lanes of i32
u8x16          # 16 lanes of u8

The grammar is <u|i|f><width>(x<count>)*. Higher dimensions such as f32x4x4 are legal grammatically; the compiler ships only the entries its target backends can accelerate.

Pointers

*T is a pointer to a value of type T. Take an address with ? and read through it with @.

var x: i64;
var p: *i64 = ?x;       # address-of yields a pointer
val v: i64  = @p;       # dereference reads through it

Arrays

[N]T is an array of exactly N values of type T. Arrays nest as [N][M]T.

val a: [4]i64    = [4]i64{1, 2, 3, 4};
val g: [2][2]i64 = [2][2]i64{ [2]i64{1, 2}, [2]i64{3, 4} };

Function types

fun(T1, T2) R is a first-class function-pointer type, usable as a value's type just like any scalar.

def BinOp: fun(i64, i64) i64;
val op: BinOp = add;
val r:  i64   = op(2, 3);

Named types and aliases

rec and uni declarations produce named types. A def introduces an alias for any type, including the constructed forms above.

def Bytes: [16]u8;     # Bytes now names an array type
def bool: u8;          # the stdlib's own bool alias