Módulo:Arguments: diferenças entre revisões

4 227 bytes adicionados ,  23h05min de 28 de novembro de 2018
(Cópia de w:en:Module:Arguments (créditos: Mr. Stradivarius e Anomie))
 
 
-- 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 called from #invoke directly.
-- called from #invoke directly.
 
local libraryUtil = require('libraryUtil')
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)
return val
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)
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
if type(frame.args) == 'table' and type(frame.getParent) == 'function' then
if not options.parentOnlywrappers 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
if options.parentFirst then
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
if tidyVal 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
elseif options.trim ~= false then
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 precedence.
-- 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 key, val in iteratorpairs(t) do
localif metaArgsValmetaArgs[key] == metaArgsnil and nilArgs[key] ~= 'h' then
if metaArgsVal == nil or metaArgsVal == nilArg then
local tidiedVal = tidyVal(key, val)
if tidiedVal == nil then
metaArgsnilArgs[key] = nilArg's'
else
metaArgs[key] = tidiedVal
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, 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)
--[[
-- 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]
if val ~= nil then
ifreturn val == nilArg then
elseif metatable.donePairs or nilArgs[key] then
return nil
elsereturn nil
return val
end
end
for _, argTable in ipairs(argTables) do
local argTableVal = tidyVal(key, argTable[key])
if argTableVal =~= nil then
metaArgs[key] = nilArg
else
metaArgs[key] = argTableVal
return argTableVal
end
end
nilArgs[key] = 'h'
return nil
end
 
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
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
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
--[[
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
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
 
metatable.__pairs = function ()
-- Called when pairs is run on the args table.
if not metatable.donePairs then
mergeArgs(pairs, argTables)
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
return translatenext, { t = metaArgs }
end
 
metatable.__ipairs =local function inext(t, i)
-- 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
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