Editing Module:Arguments

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-- This module provides easy processing of arguments passed to Scribunto from
-- This module provides easy processing of arguments passed to Scribunto from #invoke.
-- #invoke. It is intended for use by other Lua modules, and should not be
-- It is intended for use by other Lua modules, and should not be called from #invoke directly.
-- called from #invoke directly.


local libraryUtil = require('libraryUtil')
local libraryUtil = require('libraryUtil')
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local arguments = {}
local arguments = {}


-- Generate four different tidyVal functions, so that we don't have to check the
local nilArg = {} -- Used for memoizing nil arguments in metaArgs.
-- options every time we call it.
 
-- Generate four different tidyVal functions, so that we don't have to check the options every time we call it.


local function tidyValDefault(key, val)
local function tidyValDefault(key, val)
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return val
return val
end
end
local function matchesTitle(given, title)
local tp = type( given )
return (tp == 'string' or tp == 'number') and mw.title.new( given ).prefixedText == title
end
local translate_mt = { __index = function(t, k) return k end }


function arguments.getArgs(frame, options)
function arguments.getArgs(frame, options)
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options = options or {}
options = options or {}


--[[
-- Get the arguments from the frame object if available. If the frame object is not available, we are being called
-- Set up argument translation.
-- from another Lua module or from the debug console, so assign the args to a new variable so we can differentiate them.
--]]
options.translate = options.translate or {}
if getmetatable(options.translate) == nil then
setmetatable(options.translate, translate_mt)
end
if options.backtranslate == nil then
options.backtranslate = {}
for k,v in pairs(options.translate) do
options.backtranslate[v] = k
end
end
if options.backtranslate and getmetatable(options.backtranslate) == nil then
setmetatable(options.backtranslate, {
__index = function(t, k)
if options.translate[k] ~= k then
return nil
else
return k
end
end
})
end
 
--[[
-- Get the argument tables. If we were passed a valid frame object, get the
-- frame arguments (fargs) and the parent frame arguments (pargs), depending
-- on the options set and on the parent frame's availability. If we weren't
-- passed a valid frame object, we are being called from another Lua module
-- or from the debug console, so assume that we were passed a table of args
-- directly, and assign it to a new variable (luaArgs).
--]]
local fargs, pargs, luaArgs
local fargs, pargs, luaArgs
if type(frame.args) == 'table' and type(frame.getParent) == 'function' then
if type(frame.args) == 'table' and type(frame.getParent) == 'function' then
if options.wrappers then
if not options.parentOnly then
--[[
fargs = frame.args
-- The wrappers option makes Module:Arguments look up arguments in
end
-- either the frame argument table or the parent argument table, but
if not options.frameOnly then
-- not both. This means that users can use either the #invoke syntax
pargs = frame:getParent().args
-- or a wrapper template without the loss of performance associated
-- with looking arguments up in both the frame and the parent frame.
-- Module:Arguments will look up arguments in the parent frame
-- if it finds the parent frame's title in options.wrapper;
-- otherwise it will look up arguments in the frame object passed
-- to getArgs.
--]]
local parent = frame:getParent()
if not parent then
fargs = frame.args
else
local title = parent:getTitle():gsub('/sandbox$', '')
local found = false
if matchesTitle(options.wrappers, title) then
found = true
elseif type(options.wrappers) == 'table' then
for _,v in pairs(options.wrappers) do
if matchesTitle(v, title) then
found = true
break
end
end
end
 
-- We test for false specifically here so that nil (the default) acts like true.
if found or options.frameOnly == false then
pargs = parent.args
end
if not found or options.parentOnly == false then
fargs = frame.args
end
end
else
-- options.wrapper isn't set, so check the other options.
if not options.parentOnly then
fargs = frame.args
end
if not options.frameOnly then
local parent = frame:getParent()
pargs = parent and parent.args or nil
end
end
end
if options.parentFirst then
if options.parentFirst then
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end
end


-- Set the order of precedence of the argument tables. If the variables are
-- Set up the args and metaArgs tables. args will be the one accessed from functions, and metaArgs will hold the actual arguments.
-- nil, nothing will be added to the table, which is how we avoid clashes
-- The metatable connects the two together.
-- between the frame/parent args and the Lua args.
local args, metaArgs, metatable = {}, {}, {}
local argTables = {fargs}
setmetatable(args, metatable)
argTables[#argTables + 1] = pargs
argTables[#argTables + 1] = luaArgs


--[[
-- Generate the tidyVal function. If it has been specified by the user, we use that; if not, we choose one of four functions
-- Generate the tidyVal function. If it has been specified by the user, we
-- depending on the options chosen. This is so that we don't have to call the options table every time the function is called.
-- use that; if not, we choose one of four functions depending on the
-- options chosen. This is so that we don't have to call the options table
-- every time the function is called.
--]]
local tidyVal = options.valueFunc
local tidyVal = options.valueFunc
if tidyVal then
if tidyVal then
if type(tidyVal) ~= 'function' then
if type(tidyVal) ~= 'function' then
error(
error("bad value assigned to option 'valueFunc' (function expected, got " .. type(tidyVal) .. ')', 2)
"bad value assigned to option 'valueFunc'"
.. '(function expected, got '
.. type(tidyVal)
.. ')',
2
)
end
end
elseif options.trim ~= false then
elseif options.trim ~= false then
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end
end


--[[
local function mergeArgs(iterator, tables)
-- Set up the args, metaArgs and nilArgs tables. args will be the one
-- Accepts multiple tables as input and merges their keys and values into one table using the specified iterator.
-- accessed from functions, and metaArgs will hold the actual arguments. Nil
-- If a value is already present it is not overwritten; tables listed earlier have precendence.
-- arguments are memoized in nilArgs, and the metatable connects all of them
-- We are also memoizing nil values, but those values can be overwritten.
-- together.
--]]
local args, metaArgs, nilArgs, metatable = {}, {}, {}, {}
setmetatable(args, metatable)
 
local function mergeArgs(tables)
--[[
-- Accepts multiple tables as input and merges their keys and values
-- into one table. If a value is already present it is not overwritten;
-- tables listed earlier have precedence. We are also memoizing nil
-- values, which can be overwritten if they are 's' (soft).
--]]
for _, t in ipairs(tables) do
for _, t in ipairs(tables) do
for key, val in pairs(t) do
for key, val in iterator(t) do
if metaArgs[key] == nil and nilArgs[key] ~= 'h' then
local metaArgsVal = metaArgs[key]
if metaArgsVal == nil or metaArgsVal == nilArg then
local tidiedVal = tidyVal(key, val)
local tidiedVal = tidyVal(key, val)
if tidiedVal == nil then
if tidiedVal == nil then
nilArgs[key] = 's'
metaArgs[key] = nilArg
else
else
metaArgs[key] = tidiedVal
metaArgs[key] = tidiedVal
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end
end
end
end
-- Set the order of precedence of the argument tables. If the variables are nil, nothing will be added to the table,
-- which is how we avoid clashes between the frame/parent args and the Lua args.
local argTables = {fargs}
argTables[#argTables + 1] = pargs
argTables[#argTables + 1] = luaArgs


--[[
--[[
-- Define metatable behaviour. Arguments are memoized in the metaArgs table,
-- Define metatable behaviour. Arguments are memoized in the metaArgs table, and are only fetched from the
-- and are only fetched from the argument tables once. Fetching arguments
-- argument tables once. Nil arguments are also memoized using the nilArg variable in order to increase
-- from the argument tables is the most resource-intensive step in this
-- performance. Also, we keep a record in the metatable of when pairs and ipairs have been called, so we
-- module, so we try and avoid it where possible. For this reason, nil
-- do not run pairs and ipairs on fargs and pargs more than once. We also do not run ipairs on fargs and
-- arguments are also memoized, in the nilArgs table. Also, we keep a record
-- pargs if pairs has already been run, as all the arguments will already have been copied over.
-- in the metatable of when pairs and ipairs have been called, so we do not
-- run pairs and ipairs on the argument tables more than once. We also do
-- not run ipairs on fargs and pargs if pairs has already been run, as all
-- the arguments will already have been copied over.
--]]
--]]


metatable.__index = function (t, key)
metatable.__index = function (t, key)
--[[
-- Fetches an argument when the args table is indexed. First we check
-- to see if the value is memoized, and if not we try and fetch it from
-- the argument tables. When we check memoization, we need to check
-- metaArgs before nilArgs, as both can be non-nil at the same time.
-- If the argument is not present in metaArgs, we also check whether
-- pairs has been run yet. If pairs has already been run, we return nil.
-- This is because all the arguments will have already been copied into
-- metaArgs by the mergeArgs function, meaning that any other arguments
-- must be nil.
--]]
if type(key) == 'string' then
key = options.translate[key]
end
local val = metaArgs[key]
local val = metaArgs[key]
if val ~= nil then
if val ~= nil then
return val
if val == nilArg then
elseif metatable.donePairs or nilArgs[key] then
return nil
return nil
else
return val
end
end
end
for _, argTable in ipairs(argTables) do
for _, argTable in ipairs(argTables) do
local argTableVal = tidyVal(key, argTable[key])
local argTableVal = tidyVal(key, argTable[key])
if argTableVal ~= nil then
if argTableVal == nil then
metaArgs[key] = nilArg
else
metaArgs[key] = argTableVal
metaArgs[key] = argTableVal
return argTableVal
return argTableVal
end
end
end
end
nilArgs[key] = 'h'
return nil
return nil
end
end


metatable.__newindex = function (t, key, val)
metatable.__newindex = function (t, key, val)
-- This function is called when a module tries to add a new value to the
-- args table, or tries to change an existing value.
if type(key) == 'string' then
key = options.translate[key]
end
if options.readOnly then
if options.readOnly then
error(
error('could not write to argument table key "' .. tostring(key) .. '"; the table is read-only', 2)
'could not write to argument table key "'
.. tostring(key)
.. '"; the table is read-only',
2
)
elseif options.noOverwrite and args[key] ~= nil then
elseif options.noOverwrite and args[key] ~= nil then
error(
error('could not write to argument table key "' .. tostring(key) .. '"; overwriting existing arguments is not permitted', 2)
'could not write to argument table key "'
.. tostring(key)
.. '"; overwriting existing arguments is not permitted',
2
)
elseif val == nil then
elseif val == nil then
--[[
metaArgs[key] = nilArg -- Memoize nils.
-- If the argument is to be overwritten with nil, we need to erase
-- the value in metaArgs, so that __index, __pairs and __ipairs do
-- not use a previous existing value, if present; and we also need
-- to memoize the nil in nilArgs, so that the value isn't looked
-- up in the argument tables if it is accessed again.
--]]
metaArgs[key] = nil
nilArgs[key] = 'h'
else
else
metaArgs[key] = val
metaArgs[key] = val
end
end
local function translatenext(invariant)
local k, v = next(invariant.t, invariant.k)
invariant.k = k
if k == nil then
return nil
elseif type(k) ~= 'string' or not options.backtranslate then
return k, v
else
local backtranslate = options.backtranslate[k]
if backtranslate == nil then
-- Skip this one. This is a tail call, so this won't cause stack overflow
return translatenext(invariant)
else
return backtranslate, v
end
end
end
end
end


metatable.__pairs = function ()
metatable.__pairs = function ()
-- Called when pairs is run on the args table.
if not metatable.donePairs then
if not metatable.donePairs then
mergeArgs(argTables)
mergeArgs(pairs, argTables)
metatable.donePairs = true
metatable.donePairs = true
metatable.doneIpairs = true
end
return function ( t, k )
local nk, val = next( metaArgs, k )
if val == nilArg then
val = nil
end
return nk, val
end
end
return translatenext, { t = metaArgs }
end
end


local function inext(t, i)
metatable.__ipairs = function ()
-- This uses our __index metamethod
if not metatable.doneIpairs then
local v = t[i + 1]
mergeArgs(ipairs, argTables)
if v ~= nil then
metatable.doneIpairs = true
return i + 1, v
end
end
end
return function ( t, i )
 
local val = metaArgs[i + 1]
metatable.__ipairs = function (t)
if val == nil then
-- Called when ipairs is run on the args table.
return nil
return inext, t, 0
elseif val == nilArg then
val = nil
end
return i + 1, val
end, nil, 0
end
end


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