Syntax quick reference

Declarations

var value: i32 = 1;
var next: i32 = value + 1;
const LIMIT: i32 = 64;
static total: i64 = 0;
type Identifier = u64;

var is the local form and requires an explicit type. const and static are top-level declarations.

Functions

fun max(left: i32, right: i32) -> i32 {
    if (left > right) {
        return left;
    }
    return right;
}

Generics

fun identity<T>(value: T) -> T {
    return value;
}

var value: i32 = identity<i32>(10);

Generic calls require explicit type arguments.

Structs and enums

struct Pair {
    left: i32;
    right: i32;
}

enum Result -> i32 {
    Ok = 0,
    Error,
}

Conditionals and loops

if (ready) {
    println("ready");
}

while (count < 10) {
    count += 1;
}

for (var i: i32 = 0; i < 10; i += 1) {
    println("{}", i);
}

match (status) {
    Ready => { println("ready"); }
    0 => { println("zero"); }
    _ => { println("other"); }
}

if, while, for, and match use parenthesized headers.

Arrays and pointers

var values: array<i32, 4> = [1, 2, 3, 4];
var p: ptr<i32> = &values[0];
var first: i32 = deref p;

Console I/O

print("value = ");
println("{}", value);
input("{}", value);

The first argument is a string literal. Each exact {} placeholder requires one following expression; input destinations must be assignable.

Imports and FFI

import("std::string::len")::{len};
import("./helpers" as helpers);
import("math")::{add, Point};
extern(c) fun native_call(value: i32) -> i32;

export(c) fun wave_call(value: i32) -> i32 {
    return value + 1;
}

Use pub on declarations imported by other Wave modules, and pub import("path")::{name}; to re-export selected public names.

Target-conditioned items

#[target(os="linux", arch="riscv64")]
extern(c) fun platform_call(value: i32) -> i32;

Supported condition keys are arch, os, env, and abi. The attribute controls the next top-level item.

Inline assembly

var result: i64 = 0;
asm {
    "mv a0, a1"
    in("a1") 7
    out("a0") result
    clobber("memory")
}

Instruction text and register names are target-specific. Declare every input, output, and hidden clobber required by the block.

Compiler queries

wavec build main.wave --emit=check
wavec print supported-targets
wavec print supported-emit-kinds