Macro into_matrix 

macro_rules! into_matrix {
    () => { ... };
    (;$domain:expr) => { ... };
    ($x:expr) => { ... };
    ($x:expr;$domain:expr) => { ... };
}

Creates a new matrix AbstractLiteral from some Vec, optionally with some index domain.

• matrix![my_vec]
• matrix![my_vec;my_domain]

To create one from a list of elements, use matrix!.