2-d matrices

In matrix.diesel:

A matrix is a two-dimensional indexable collection.

Matrices support querying the number of rows and columns of a matrix, extracting an element, a row, or a column of the matrix. The do and indices_do methods support iterating over the matrix. Conformable matrices can be added and multiplied. A matrix of comparable values is itself comparable, pointwise. Mutable matrices support changing a given matrix element.

One concrete implementation of matrices exists, based on representing matrices by a vector of vectors. The new_vector_matrix_init functions supports creating a new vector_matrix of a given size with its elements initialized as specified by the init_fn closure.

extend module Stdlib;

module Matrix;
abstract class matrix[T];
  fun num_rows(:matrix[`T]):int;
  fun num_cols(:matrix[`T]):int;
  fun fetch(:matrix[`T], row:int, col:int):T;
  fun row(m:matrix[`T], row:int):indexed[T];
  fun col(m:matrix[`T], col:int):indexed[T];
  fun rows(m:matrix[`T]):indexed[indexed[T]];
  fun indices_do(m:matrix[`T], c:&(int,int):void):void;
  fun do(m:matrix[`T], c:&(int,int,T):void):void;
  fun +(m1:matrix[`T <= num], m2:matrix[T]):matrix[T];
  fun *(m1:matrix[`T >= int <= num], m2:matrix[T]):matrix[T];
  fun *_ugly(m1:matrix[`T >= int <= num], m2:matrix[T]):matrix[T];
  extend class matrix[`T <= comparable[T]] isa comparable[matrix[T]];
  fun copy_init(m:matrix[`T], num_rows:int, num_cols:int,
                       init:&(int,int):T):matrix[T];
  fun copy_init[T](:matrix[T], num_rows:int, num_cols:int,
                          init:&(int,int):T):matrix[T];
  fun copy_mutable_init(m:matrix[`T], num_rows:int, num_cols:int,
                               init:&(int,int):T):m_matrix[T];
  fun copy_mutable_init[T](:matrix[T], num_rows:int, num_cols:int,
                                  init:&(int,int):T):m_matrix[T];
abstract class m_matrix[T] isa matrix[T];
  fun store(:matrix[`T], row:int, col:int, value:T):void;
class vector_matrix[T] isa m_matrix[T];
  fun new_vector_matrix_init[T](num_rows:int, num_cols:int,
                                       init:&(int,int):T):m_matrix[T];

end module Matrix;