Module:Layout/Production/Library/Array

 Deze module is nog in ontwikkeling (versie 0.0) en wordt getest.

De Module:Layout is bedoeld om snel, consistent en uitgebreid een pagina op te maken.
Er is een op de module afgestemde handleiding over deze onderwijswiki beschikbaar.

De module wordt geïnitialiseerd met de configuratie in Module:Layout/Production/Configuration.

Controleer op scriptfouten of opmaak notificaties.

Test

Deze module wordt getest door Module:Layout/Production/Test/Array.

All 3 tests are ok.

	Name	Expected	Actual
	test_array_copy
	test_array_search
	test_array_slice

Code

---

local array = {};

-- This function makes a unique duplicate in stead of a reference to an array including its nested tables.
-- The resulting "deep" copy contains no references to the original table or its nested tables.
-- For copying elements in the table that are functions this does NOT work be aware.
-- In Lua, you cannot directly create a copy of a function.
-- You can use the loadstring function to create a new function with the same body as the original function.
-- Only functions with upvalues (external local variables) using this method will not preserve the upvalues in the copied function. 
-- If your array has functions that rely on upvalues, you may need a more advanced approach to deep copy the array.
function array.copy( original )
    local original_type = type( original );
    local copy;
    if original_type == 'table' then
        copy = {};
        -- We use this function recursively for all the elements in the table to get as deep as needed for nested tables.
        for original_key, original_value in next, original, nil do
            copy[ array.copy( original_key ) ] = array.copy( original_value );
        end
        -- A metatable is a table that can be associated with another table to provide additional behavior,
        -- like customizing how the table handles arithmetic operations or indexing.
        -- Also the metatable must have a "deep" copy.
        setmetatable( copy, array.copy( getmetatable( original ) ) );
    else -- number, string, boolean, etc
    	-- No worries for referencing in stead of copying
        copy = original;
    end
    return copy;
end

-- The array.slice function takes a table (slice_table), 
-- along with optional first, last, and step arguments, 
-- and returns a new table containing a slice of the original table.
-- This function allows negative indexing, counting from the end of the table.
function array.slice( slice_table, first, last, step )
-- Initializes an empty table called sliced which will store the elements of the slice.
  local sliced = {};
  -- Handle a negative start
  if first ~= nil and first < 0 then first = first + #slice_table + 1; end
  -- Handle a negative end
  if last ~= nil and last < 0 then last = last + #slice_table + 1; end
  for i = first or 1, last or #slice_table, step or 1 do
    sliced[ #sliced + 1 ] = slice_table[ i ];
  end
  return sliced;
end

-- This function searches for a value in a certain table and returns the key if the value is found
function array.search( search_table, search_value, case_insensitive ) -- : integer 
    -- If case_insensitive is not set explicively to true, use case-sensitive search.
    case_insensitive = case_insensitive or false;

    -- Iterate through each key-value pair in the table.
    for key, value in pairs(search_table) do
        -- Check if the value matches the search value, using a case-sensitive or case-insensitive comparison as requested.
        if ( not case_insensitive and value == search_value ) or ( case_insensitive and string.lower( value ) == string.lower( search_value ) ) then
            -- If the search value is found, return the corresponding key.
            return key;
        end
    end
    
    -- If the search value is not found, return false to indicate failure.
    return false;
end

return array;