Names and Keywords

Whim names are case-sensitive. User, user, and USER are three names.

Variables and symbols

A variable starts with $:

$value = 42;

Declared symbols do not:

const LIMIT = 10;

function limit(int $value): int {
  if ($value > LIMIT) {
    return LIMIT;
  }

  return $value;
}

Classes, interfaces, enums, functions, constants, aliases, and newtypes share one symbol table. Two such declarations cannot use the same qualified name.

Properties have their own member names. Methods, class constants, and enum cases share the class-like member table. They cannot reuse one name in the same family.

Qualified names

A backslash separates namespace parts:

App\Model\User

A leading backslash starts at the global namespace:

\Whim\Json\encode

Without that leading slash, Whim resolves a qualified name through imports and the current namespace.

The reserved _ name

The bare name _ cannot name any symbol or member. Whim uses it as a wildcard, a match default, and an unnamed generic slot.

Variables include $, so $_ is valid. It is an ordinary variable, not a discard:

$_ = 'kept';
assert!($_ == 'kept');

Keyword levels

Whim has three keyword levels.

Full keywords, such as if, match, and return, cannot name a function or a constant. Soft keywords, as and is, may name functions but not constants. Context keywords, such as class, int, and readonly, may name functions or constants where the parser can tell what they mean.

Every keyword may name a class-like member because ->, ?->, ::, or a member declaration makes that use clear:

final class Tokens {
  public const MATCH = 'match';

  public function match(): string {
    return self::MATCH;
  }
}

assert!(new Tokens()->match() == 'match');

The keyword appendix lists every word and its level.