Changes
fix undefined next() behaviour bug by checking for metatable.donePairs in the __index metamethod; also, format the module so it fits into 80 characters
-- This module provides easy processing of arguments passed to Scribunto from -- #invoke.-- It is intended for use by other Lua modules, and should not be -- called from #invoke directly.
local libraryUtil = require('libraryUtil')
local checkType = libraryUtil.checkType
local arguments = {}
local nilArg = {} -- Used for memoizing nil arguments in metaArgs.
local function tidyValDefault(key, val)
if type(val) == 'string' then
end
end
local function tidyValTrimOnly(key, val)
if type(val) == 'string' then
end
end
local function tidyValRemoveBlanksOnly(key, val)
if type(val) == 'string' then
end
end
local function tidyValNoChange(key, val)
return val
end
function arguments.getArgs(frame, options)
checkType('getArgs', 1, frame, 'table', true)
frame = frame or {}
options = options or {}
local fargs, pargs, luaArgs
if type(frame.args) == 'table' and type(frame.getParent) == 'function' then
luaArgs = frame
end
local args, metaArgs, metatable = {}, {}, {}
setmetatable(args, metatable)
local tidyVal = options.valueFunc
if tidyVal then
if type(tidyVal) ~= 'function' then
error( "bad value assigned to option 'valueFunc'" .. ' (function expected, got " ' .. type(tidyVal) .. ')', 2 )
end
elseif options.trim ~= false then
end
end
local function mergeArgs(iterator, tables)
--[[ -- Accepts multiple tables as input and merges their keys and values -- into one table using the specified iterator. -- If a value is already -- present it is not overwritten; tables listed earlier have precedence. -- We are also memoizing nil values, but those values can be -- overwritten. --]]
for _, t in ipairs(tables) do
for key, val in iterator(t) do
end
end
local argTables = {fargs}
argTables[#argTables + 1] = pargs
argTables[#argTables + 1] = luaArgs
--[[
-- Define metatable behaviour. Arguments are memoized in the metaArgs table, -- and are only fetched from the -- argument tables once. Nil arguments are -- also memoized using the nilArg variable in order to increaseperformance. -- performance. Also, we keep a record in the metatable of when pairs and ipairs have -- been called, so we -- do not run pairs and ipairs on fargs and pargs more -- than once. We also do not run ipairs on fargs andpargs if pairs has -- pargs if pairs has already been run, as all the arguments will already have been copied -- over.
--]]
metatable.__index = function (t, key)
local val = metaArgs[key]
if metatable.donePairs or val ~= nil then --[[ -- We have either memoized the argument already, or pairs has been -- called, meaning that mergeArgs has already copied all of the -- available arguments into the metaArgs table. We need to check for -- pairs as we can't memoize nils to the metaArgs table while pairs -- is iterating. Adding new instances of nilArg to the metaArgs -- table while pairs is iterating over it produces undefined -- behaviour in the next() function. --]]
if val == nilArg then
return nil
return nil
end
metatable.__newindex = function (t, key, val)
if options.readOnly then
error( 'could not write to argument table key "' .. tostring(key) .. '"; the table is read-only', 2 )
elseif options.noOverwrite and args[key] ~= nil then
error( 'could not write to argument table key "' .. tostring(key) .. '"; overwriting existing arguments is not permitted', 2 )
elseif val == nil then
metaArgs[key] = nilArg -- Memoize nils.
end
end
metatable.__pairs = function ()
if not metatable.donePairs then
end
end
metatable.__ipairs = function ()
if not metatable.doneIpairs then
end, nil, 0
end
return args
end
return arguments