Programming Flix

Primitive Types

Flix supports the primitive types:

Float64 and Int32 values can be written without suffix, i.e. 123.0f64 can simply be written as 123.0 and 123i32 can be written as 123.

Built-in Literals

Flix has built-in syntactic sugar for lists, sets, maps and regex.

List Literals

A list literal is written using the infix :: constructor. For example:

1 :: 2 :: 3 :: Nil

which is syntactic sugar for:

Cons(1, Cons(2, Cons(3, Nil)))

Alternatively, the same list can also be written as:

List#{1, 2, 3}

Set Literals

A set literal is written using the notation Set#{v1, v2, ...}. For example:

Set#{1, 2, 3}

which is syntactic sugar for:

Set.insert(3, Set.insert(2, Set.insert(1, Set.empty())))

Note that the elements are inserted from left to right, thus 1 is inserted first.

Map Literals

A map literal is written using the notion Map#{k1 => v1, k2 => v2, ...}. For example:

Map#{1 => "Hello", 2 => "World"}

which is syntactic sugar for:

Map.insert(2, "World", Map.insert(1, "Hello", Map.empty()))

Note that similar to sets above, the entries are inserted left to right. In particular, if multiple entries share the same key, the rightmost one overwrites the previous values.

Regex Literals

A regex literal is written using the notation regex"...". For example:

Regex.isMatch(regex"abc", "abc")

Additionally, regex literals support regex escape sequences with the following notation regex"\\...". For example:

Regex.isMatch(regex"\\w", "W")