.weaschem: initial, UNTESTED, parsing implementation

....it's not hooked up at all yet.
WEA will not even load the file yet, and we don't have tests either
....tests might be a bit of a problem given we use minetest.parse_json directly.
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Starbeamrainbowlabs 2023-08-12 03:05:10 +01:00
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@ -0,0 +1,256 @@
local weac = worldeditadditions_core
local Vector3 = weac.Vector3
--- Library for parsing .weaschem WorldEditAdditions Schematic files.
--
-- Most of these functions return 3 values rather than the usual 2. This might seem overcomplicated, but it enables a higher level of validation in automated testing. These 3 return values take the following form:
--
-- 1. bool: A success/failure bool. `true` means success, and `false`, means failure.
-- 2. string: The error code. "SUCCESS" if #1 (the bool) is `true`. Otherwise set to a code to indicate exactly which error ocurred.
-- 3. any|string: EITHER the expected return value, OR a string with a human-readable error message if `bool=false`.
-- @namespace worldeditadditions_core.parse.file.weaschem
local weaschem = {}
--- Validates and converts a raw table into a Vector3 instance.
-- @param source_obj table The table to convert.
-- @returns bool,string,Vector3|string A success bool, then an error code, then finally EITHER the resulting Vector3 instance (if bool=true) OR an error message as a string.
function weaschem.parse_vector3(source_obj)
if type(source_obj) ~= "table" then return false, "VECTOR3_INVALID_TYPE", "Vector3: Expected a table, but got a value of type '"..type(source_obj).."'." end
if source_obj.x == nil then return false, "VECTOR3_NO_X", "Vector3: No value for the x coordinate was found." end
if source_obj.y == nil then return false, "VECTOR3_NO_Y", "Vector3: No value for the y coordinate was found." end
if source_obj.z == nil then return false, "VECTOR3_NO_Z", "Vector3: No value for the z coordinate was found." end
if type(source_obj.x) ~= "number" then return false, "VECTOR3_INVALID_X", "Vector3: The type of the x coordinate was expected to be number, but found '"..type(source_obj.x).."'." end
if type(source_obj.y) ~= "number" then return false, "VECTOR3_INVALID_Y", "Vector3: The type of the y coordinate was expected to be number, but found '"..type(source_obj.y).."'." end
if type(source_obj.z) ~= "number" then return false, "VECTOR3_INVALID_Z", "Vector3: The type of the z coordinate was expected to be number, but found '"..type(source_obj.z).."'." end
local result = Vector3.clone(source_obj)
return true, "SUCCESS", result
end
function weaschem.parse_header(source)
local raw_obj = minetest.parse_json(source)
if raw_obj == nil then return false, "HEADER_INVALID", "The header is invalid JSON." end
local header = {}
if raw_obj["name"] == nil then return false, "HEADER_NO_NAME", "No name property found in header."
else
header["name"] = raw_obj["name"]
if type(header["name"]) ~= "string" then
return false, "HEADER_NAME_INVALID",
"Invalid name in header: expected string, but found value of type '"..type(raw_obj["name"])"'."
end
end
if raw_obj["description"] ~= nil then
header["description"] = raw_obj["description"]
if type(header["description"]) ~= "string" then
return false, "HEADER_DESCRIPTION_INVALID",
"Invalid description in header: expected string, but found value of type '" .. type(raw_obj["description"]) "'."
end
end
if raw_obj["offset"] == nil then
return false, "HEADER_NO_OFFSET", "No offset property found in header."
else
local success, code, result = weaschem.parse_vector3(raw_obj["offset"])
if not success then return success, code, result end
header["offset"] = result
end
if raw_obj["size"] == nil then return false, "HEADER_NO_SIZE", "No size property found in header."
else
local success, code, result = weaschem.parse_vector3(raw_obj["size"])
if not success then return success, code, result end
header["size"] = result
end
if raw_obj["type"] == nil then
return false, "HEADER_NO_TYPE", "No type property found in header."
else
header["type"] = raw_obj["type"]
if type(header["type"]) ~= "string" then
return false, "HEADER_TYPE_INVALID",
"Invalid type in header: expected string, but found value of type '" .. type(raw_obj["type"]) "'."
end
if header["type"] ~= "full" and header["type"] ~= "delta" then
return false, "HEADER_TYPE_INVALID",
"The value of the header field type was expected to be 'full' or 'delta', but was found to be '" ..
tostring(header["type"]) .. "'."
end
end
if raw_obj["generator"] == nil then
return false, "HEADER_NO_GENERATOR", "No generator property found in header."
else
header["generator"] = raw_obj["generator"]
if type(header["generator"]) ~= "string" then
return false, "HEADER_GENERATOR_INVALID",
"Invalid generator in header: expected string, but found value of generator '" .. type(raw_obj["generator"]) "'."
end
end
return true, "SUCCESS", header
end
function weaschem.parse_id_map(source)
local raw_obj = minetest.parse_json(source)
if raw_obj == nil then return false, "ID_MAP_INVALID", "The node id map is invalid JSON." end
local result = {}
for id_str, node_name in pairs(raw_obj) do
local id = tonumber(id_str)
if id == nil then return false, "ID_MAP_INVALID_ID", "A node id in the node id map is not parsable as a number." end
if string.find(node_name, ":") == nil then return false, "ID_MAP_RELATIVE_NODE_NAME", "A node name does not contain a colon, suggesting it is a relative node id. Relative node ids are not supported." end
if result[id] ~= nil then return false, "ID_MAP_DUPLICATE", "Multiple node ids in the node id map parse to the same number." end
result[id] = node_name
end
return true, "SUCCESS", result
end
function weaschem.parse_data_table(source)
local data_table = {}
local values = weac.split(source, ",", true)
local i = 0
for _, next_val in pairs(values) do
if next_val:find("x") ~= nil then
local multi_count, multi_node_id = string.match(next_val, "(%d+)x(%d+)")
multi_count = tonumber(multi_count)
if type(multi_count) ~= "number" then
return false, "DATA_TABLE_INVALID_COUNT", "Encountered count value in data table at position '"..tostring(i).."'."
end
multi_node_id = tonumber(multi_node_id)
if type(multi_node_id) ~= "number" then
return false, "DATA_TABLE_INVALID_NODE_ID", "Encountered node id value in data table at position '"..tostring(i).."'."
end
for _ = 1,multi_count do
data_table[i] = multi_node_id
i = i + 1
end
else
local node_id = tonumber(next_val)
if type(multi_count) ~= "number" then
return false, "DATA_TABLE_INVALID_NODE_ID",
"Encountered node id value in data table at position '" .. tostring(i) .. "'."
end
data_table[i] = node_id
i = i + 1
end
end
return true, "SUCCESS", data_table
end
--- Parses the WorldEditAdditions schematic file from the given handle.
-- This requires a file handle, as significant optimisations can be made in the case of invalid files.
-- @param handle File A Lua file handle to read from.
-- @param delta_which string If the schematic file is of type delta (i.e. as opposed to full), then this indicates which state is desired. Useful to significantly optimise both CPU and memory usage by avoiding parsing more than necessary if only one state is desired. Possible values: both (default; read both the previous and current states), prev (read only the previous state), current (read only the current state).
-- @returns TODO DOCUMENT THIS.
function weaschem.parse(handle, delta_which)
if delta_which == nil then delta_which = "both" end
if delta_which ~= "both" and delta_which ~= "prev" and delta_which ~= "current" then
return false, "INVALID_DELTA_WHICH", "Invalid delta_which argument. Possible values: both [default], prev, current."
end
local temp, temp2 = handle:read(8, 1)
if temp ~= "WEASCHEM" then
return false, "INVALID_MAGIC_BYTES", "The magic bytes 'WEASCHEM' were not found, so the input is an invalid .weaschem schematic."
end
if temp2 ~= " " then
return false, "INVALID_MAGIC_SPACE", "Invalid character after magic bytes (expected a single U+20 space)"
end
local version = handle:read("*n")
if version ~= 1 then
return false, "INVALID_VERSION", "Invalid schematic version. Expected 1, but found '"..tostring(version).."'."
end
temp = handle:read(1)
if temp ~= "\n" then
return false, "UNEXPECTED_TOKEN", "Invalid character present after schematic version number (expected a new line character U+0A)"
end
temp = handle:read("*l")
local success, code, header = weaschem.parse_header(temp)
if not success then return success, code, header end
temp = handle:read("*l")
if temp == nil then return false, "NO_ID_MAP", "Unable to read the id map from the file." end
local id_map
success, code, id_map = weaschem.parse_id_map(temp)
if not success then return success, code, id_map end
local data_tables = {}
if header["type"] == "full" then
temp = handle:read("*l")
if temp == nil then return false, "NO_DATA_TABLE", "Unable to read the data table full:data from the file." end
success, code, temp2 = weaschem.parse_data_table(temp)
if not success then return success, code, temp2 end
data_tables["data"] = temp2
temp = handle:read("*l")
if temp == nil then return false, "NO_DATA_TABLE", "Unable to read the data table full:param2 from the file." end
success, code, temp2 = weaschem.parse_data_table(temp)
if not success then return success, code, temp2 end
data_tables["param2"] = temp2
else
temp = handle:read("*l")
if temp == nil then return false, "NO_DATA_TABLE", "Unable to read the data table delta:data_previous from the file." end
-- delta_which="current" is the only state in which we would NOT want to parse the previous state. Regardless, we still need to read the line in though even if we immediately discard it otherwise we'll be out of sync.
if delta_which ~= "current" then
success, code, temp2 = weaschem.parse_data_table(temp)
if not success then return success, code, temp2 end
data_tables["data_prev"] = temp2
end
temp = handle:read("*l")
if temp == nil then return false, "NO_DATA_TABLE", "Unable to read the data table delta:param2_previous from the file." end
if delta_which ~= "current" then
success, code, temp2 = weaschem.parse_data_table(temp)
if not success then return success, code, temp2 end
data_tables["param2_prev"] = temp2
end
temp = handle:read("*l")
if temp == nil then return false, "NO_DATA_TABLE", "Unable to read the data table delta:data_current from the file." end
if delta_which ~= "prev" then
success, code, temp2 = weaschem.parse_data_table(temp)
if not success then return success, code, temp2 end
data_tables["data_current"] = temp2
end
temp = handle:read("*l")
if temp == nil then return false, "NO_DATA_TABLE", "Unable to read the data table delta:param2_current from the file." end
if delta_which ~= "prev" then
success, code, temp2 = weaschem.parse_data_table(temp)
if not success then return success, code, temp2 end
data_tables["param2_current"] = temp2
end
end
local result = {
header = header,
id_map = id_map,
data_tables = data_tables
}
return true, "SUCCESS", result
end
return weaschem