Feature: matrix and union

[timoniq]

Matrix

: ?transpose('T'[x][y]) -> 'T'[y][x].

To make size variables invisible in predicate case's scope their names should start with underscore, such as _x.

Implementation. After such cast matrix will gain matrix-confirmation.

Union

Builtin union template – external datatype sets union operator.

union<'T', ...>
optional<'T'>

s = 1 .. 3;
optional<s> a;

Declaration of a optional<'T'> template

none_T ~ @{none}.
optional<'T'> = union<'T', none_T>

Solutions: @none, 1, 2, 3.

: ?transpose_array('T'[][]) -> optional<'T'>[][].

todo

• [ ] matrix
• [x] union

[timoniq]

union feature completed

union instance can be used as predicate:

x = union(int, string);

or with type clarification:

x ~ union{int, string};
-- also it can have more than two types here
y ~ union{int, int[], string};
-- clarification will automatically wrap into nested union:
-- union(int, union(int[], string))

optional is made out of any type and @Nothing atom from Nothing universum.

optional_int ~ union{int, Nothing};