class
	MATRIX_CALCULATOR

inherit
	ARRAYED_LIST [ARRAY [REAL]]
		rename
			make as make_array,
			last as row,
			count as row_count
		end

	EL_BUILDABLE_FROM_XML
		undefine
			copy, is_equal
		redefine
			make_default, building_action_table, PI_building_action_table
		end

	OUTPUT_ROUTINES

create
	make_from_file, make_from_string, make_default

feature {NONE} -- Initialization

	make_default
			--
		do
			make_array (10)
			Precursor
			create vector_result.make (1, 0)
			create row_sum.make (1, 0)
		end

feature -- Access

	vector_result: ARRAY [REAL]

feature -- Basic operations

	find_column_sum
			-- find sum of columns
		local
			i: INTEGER
		do
			vector_result.grow (row.count)
			from start until after loop
				from i := 1 until i > row.count loop
					vector_result [i] := vector_result [i] + row [i]
					i := i + 1
				end
				forth
			end
			log_vector_result ("Sum")
		end

	find_column_average
			-- find average of columns
		local
			i: INTEGER
		do
			find_column_sum
			from i := 1 until i > row.count loop
				vector_result [i] := vector_result [i] / row_count
				i := i + 1
			end
			log_vector_result ("Average")
		end

	log_vector_result (label: STRING)
			--
		do
			across vector_result as l_result loop
				lio.put_labeled_substitution (label, once "column [%S] = %S", [l_result.cursor_index, l_result.item])
				lio.put_new_line
			end
		end

feature {NONE} -- Implementation

	row_sum: ARRAY [REAL]

	col_index: INTEGER

feature {NONE} -- Building from XML

	add_row
			--
		do
			if is_empty then
				extend (create {ARRAY [REAL]}.make (1, 0))
			else
				extend (create {ARRAY [REAL]}.make (1, row.count))
			end
			log_extend (generator, Current)
			col_index := 0
		end

	add_row_col
			--
		do
			col_index := col_index + 1
			lio.put_labeled_substitution ("Calling", "row.force (%S, %S)", [node.to_real, col_index])
			lio.put_new_line
			row.force (node.to_real, col_index)
		end

	building_action_table: EL_PROCEDURE_TABLE [STRING]
			-- Relative to root node: matrix
		do
			create Result.make (<<
				-- matrix sibling node

				["row", agent add_row],
				["row/col/text()", agent add_row_col]
			>>)
		end

	PI_building_action_table: EL_PROCEDURE_TABLE [STRING]
			--
		do
			create Result.make (<<
				["find_column_sum", agent find_column_sum],
				["find_column_average", agent find_column_average]
			>>)
		end

	Root_node_name: STRING = "matrix"

end