Types

Types annotations restrict a datum without capturing it into a name. They appear after the colon : in a capture.

Type names

Wolf provides a few basic type names, some of which you’ve seen already:

• num - floating point numbers
• int - integers
• uni - the unique value - only equal to itself
• bool - boolean outcomes
• str - strings of characters
• ty - a type definition

Tuple types

As with captures, tuple syntax can be used to represent the type of various tuples.

In place of sub-values or sub-captures, sub-types are provided as entries.

[num. str, bool]
[.name str, .age num]

As shorthand for arrays with known quantities of a single type, write the quantity as an integer, followed by the type.

-- These are equivalent.
[num, num, num]
[3 num]

-- These are also equivalent.
[str, bool, bool]
[str, 2 bool]

Rest-of-tuple types

The rest of a tuple’s data can be constrained to a certain type using ellipses .... This includes both named and unnamed data.

This is most commonly used to represent dynamically-sized arrays.

-- Any quantity of strings.
[... str]

-- A name, an age, and some booleans.
[.name str, .age num, ... bool]