Minetest-WorldEditAdditions/worldeditadditions/utils/tables.lua
2021-03-17 11:36:12 -07:00

67 lines
2.1 KiB
Lua

--- Shallow clones a table.
-- @source http://lua-users.org/wiki/CopyTable
-- @param orig table The table to clone.
-- @return table The cloned table.
function worldeditadditions.shallowcopy(orig)
local orig_type = type(orig)
local copy
if orig_type == 'table' then
copy = {}
for orig_key, orig_value in pairs(orig) do
copy[orig_key] = orig_value
end
else -- number, string, boolean, etc
copy = orig
end
return copy
end
--- SHALLOW ONLY - applies the values in source to overwrite the equivalent keys in target.
-- Warning: This function mutates target!
-- @param source table The source to take values from
-- @param target table The target to write values to
function worldeditadditions.table_apply(source, target)
for key, value in pairs(source) do
target[key] = value
end
end
--- Polyfill for unpack / table.unpack.
-- Calls unpack when available, and looks for table.unpack if unpack() isn't
-- found.
-- This is needed because in Lua 5.1 it's the global unpack(), but in Lua 5.4
-- it's moved to table.unpack().
function worldeditadditions.table_unpack(tbl, offset, count)
if type(unpack) == "function" then
return unpack(tbl, offset, count)
else
return table.unpack(tbl, offset, count)
end
end
--- Returns only the last count items in a given numerical table-based list.
function worldeditadditions.table_get_last(tbl, count)
return {worldeditadditions.table_unpack(
tbl,
math.max(0, (#tbl) - (count - 1))
)}
end
--- Returns the key value pairs in a table as a single string
-- @param tbl table input table
-- @param sep string key value seperator
-- @param new_line string key value pair delimiter
-- @return string concatenated table pairs
function worldeditadditions.table_tostring(tbl, sep, new_line)
if type(sep) ~= "string" then sep = ": " end
if type(new_line) ~= "string" then new_line = ", " end
local ret = {}
if type(tbl) ~= "table" then return "Error: input not table!" end
for key,value in pairs(tbl) do
ret:append(key)
ret:append(sep)
ret:append(value)
ret:append(new_line)
end
return ret:concat("")
end