Minetest-WorldEditAdditions/worldeditadditions/utils/parse/key_instance.lua

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2022-05-24 00:06:23 +00:00
--- A container for transmitting (axis table, sign) or (dir, sign) pairs
-- and other data within parsing functions.
-- @class
local key_instance = {}
key_instance.__index = key_instance
key_instance.__name = "Key Instance"
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-- Allowed values for "type" field
local types = {
err = true, rev = true,
axis = true, dir = true,
replace = {
error = "err",
axes = "axis",
},
}
-- Simple function for putting stuff in quotes
local function enquote(take)
if type(take) == "string" then
return '"'..take..'"'
else return tostring(take) end
end
--- Creates a new Key Instance.
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-- This is a table with a "type" string, an entry string or table
-- and an optional signed integer (or code number in the case of errors)
-- @param: type: String: Key type (axis, dir(ection), rev (mirroring) or error).
-- @param: entry: String: The main content of the key.
-- @param: sign: Int: The signed multiplier of the key (if any).
-- @return: Key Instance: The new Key Instance.
function key_instance.new(type,entry,sign)
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if types.replace[type] then
type = types.replace[type]
elseif not types[type] then
return key_instance.new("err",
"Key Instance internal error: Invalid type "..enquote(type)..".",
500)
end
local tbl = {type = type, entry = entry}
if sign and sign ~= 0 then
if type == "err" then tbl.code = sign
else tbl.sign = sign end
end
return setmetatable(tbl, key_instance)
end
--- Checks if Key Instance "entry" field is a table.
-- @param: tbl: Key Instance: The Key Instance to check.
-- @return: Bool: Returns true if Key Instance has a non 0 sign value.
function key_instance.entry_table(a)
if type(a.entry) == "table" then
return true
else return false end
end
--- Checks if Key Instance has a signed multiplier.
-- @param: tbl: Key Instance: The Key Instance to check.
-- @return: Bool: Returns true if Key Instance has a non 0 sign value.
function key_instance.has_sign(a)
if not a.sign or a.sign == 0 then
return false
else return true end
end
--- Checks if Key Instance is an error.
-- @param: tbl: Key Instance: The Key Instance to check.
-- @return: Bool: Returns true if Key Instance is an error.
function key_instance.is_error(a)
if a.type == "err" then return true
else return false end
end
function key_instance.__tostring(a)
local ret = "{type = "..enquote(a.type)..", entry = "
if type(a.entry) == "table" and #a.entry <= 3 then
ret = ret.."{"
for _i,v in ipairs(a.entry) do
ret = ret..enquote(v)..", "
end
ret = ret:sub(1,-3).."}"
else ret = ret..enquote(a.entry) end
if a:is_error() and a.code then ret = ret..", code = "..a.code.."}"
elseif a:has_sign() then ret = ret..", sign = "..a.sign.."}"
else ret = ret.."}" end
return ret
end
return key_instance