Difference between revisions of "Module:Arguments"

(don't use "if frame == mw.getCurrentFrame()")
(memoize nils, add type checks for frame and options, use string library functions instead of mw.text.trim and mw.ustring.find, define four different tidyVal functions to avoid checking options every time)
Line 1: Line 1:
 
-- This module provides easy processing of arguments passed to Scribunto from #invoke.
 
-- 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.
 
-- 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 arguments = {}
 +
 +
local nilArg = {} -- Used for memoizing nil arguments in metaArgs.
 +
 +
-- 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)
 +
if type(val) == 'string' then
 +
val = val:match('^%s*(.-)%s*$')
 +
if val == '' then
 +
return nil
 +
else
 +
return val
 +
end
 +
else
 +
return val
 +
end
 +
end
 +
 +
local function tidyValTrimOnly(key, val)
 +
if type(val) == 'string' then
 +
return val:match('^%s*(.-)%s*$')
 +
else
 +
return val
 +
end
 +
end
 +
 +
local function tidyValRemoveBlanksOnly(key, val)
 +
if type(val) == 'string' then
 +
if val:find('%S') then
 +
return val
 +
else
 +
return nil
 +
end
 +
else
 +
return val
 +
end
 +
end
 +
 +
local function tidyValNoChange(key, val)
 +
return val
 +
end
  
 
function arguments.getArgs(frame, options)
 
function arguments.getArgs(frame, options)
options = type(options) == 'table' and options or {}
+
checkType('getArgs', 1, frame, 'table', true)
 +
checkType('getArgs', 2, options, 'table', true)
 +
frame = frame or {}
 +
options = options or {}
  
 
-- Get the arguments from the frame object if available. If the frame object is not available, we are being called
 
-- Get the arguments from the frame object if available. If the frame object is not available, we are being called
 
-- from another Lua module or from the debug console, so put the args in a special table so we can differentiate them.
 
-- from another Lua module or from the debug console, so put the args in a special table so we can differentiate them.
 
local fargs, pargs, luaArgs
 
local fargs, pargs, luaArgs
if type(frame) == 'table' and type(frame.args) == 'table' and type(frame.getParent) == 'function' then
+
if type(frame.args) == 'table' and type(frame.getParent) == 'function' then
fargs = frame.args
+
if not options.parentOnly then
pargs = frame:getParent().args
+
fargs = frame.args
 +
end
 +
if not options.frameOnly then
 +
pargs = frame:getParent().args
 +
end
 +
if options.parentFirst then
 +
fargs, pargs = pargs, fargs
 +
end
 
else
 
else
luaArgs = type(frame) == 'table' and frame or {}
+
luaArgs = frame
 
end
 
end
  
Line 22: Line 76:
 
setmetatable(args, metatable)
 
setmetatable(args, metatable)
  
local function tidyVal(key, val)
+
-- Generate the tidyVal function. If it has been specified by the user, we use that; if not, we choose one of four functions
-- Processes a value according to the options given to getArguments. Can trim whitespace and remove blanks.
+
-- depending on the options chosen. This is so that we don't have to call the options table every time the function is called.
-- Keys are not used here, but they can be used by user-generated functions, so defining it here to avoid breakage.
+
local tidyVal = options.valueFunc
if type(val) == 'string' then
+
if tidyVal then
if options.trim ~= false then
+
if type(tidyVal) ~= 'function' then
val = mw.text.trim(val)
+
error("bad value assigned to option 'valueFunc' (function expected, got " .. type(tidyVal) .. ')', 2)
end
+
end
if options.removeBlanks == false or mw.ustring.find(val, '%S') then
+
elseif options.trim ~= false then
return val
+
if options.removeBlanks ~= false then
end
+
tidyVal = tidyValDefault
 
else
 
else
return val
+
tidyVal = tidyValTrimOnly
 
end
 
end
end
+
else
 
+
if options.removeBlanks ~= false then
-- Use a user-generated function to tidy the values if specified.
+
tidyVal = tidyValRemoveBlanksOnly
local valueFunc = options.valueFunc
 
if valueFunc then
 
local valueFuncType = type(valueFunc)
 
if valueFuncType == 'function' then
 
tidyVal = valueFunc
 
 
else
 
else
error('type error in option "valueFunc": expected function, got ' .. valueFuncType, 2)
+
tidyVal = tidyValNoChange
 
end
 
end
 
end
 
end
Line 51: Line 100:
 
-- Accepts multiple tables as input and merges their keys and values into one table using the specified iterator.
 
-- 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 precendence.
 
-- If a value is already present it is not overwritten; tables listed earlier have precendence.
 +
-- We are also memoizing nil values, but those values can be overwritten.
 
for _, t in ipairs(tables) do
 
for _, t in ipairs(tables) do
 
for key, val in iterator(t) do
 
for key, val in iterator(t) do
if metaArgs[key] == nil then
+
local metaArgsVal = metaArgs[key]
metaArgs[key] = tidyVal(key, val)
+
if metaArgsVal == nil or metaArgsVal == nilArg then
 +
local tidiedVal = tidyVal(key, val)
 +
if tidiedVal == nil then
 +
metaArgs[key] = nilArg
 +
else
 +
metaArgs[key] = tidiedVal
 +
end
 
end
 
end
 
end
 
end
Line 61: Line 117:
  
 
-- Set the order of precedence of the argument tables. If the variables are nil, nothing will be added to the table,
 
-- 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.
+
-- which is how we avoid clashes between the frame/parent args and the Lua args.
local argTables = {}
+
local argTables = {fargs}
if options.frameOnly then
+
argTables[#argTables + 1] = pargs
table.insert(argTables, fargs)
+
argTables[#argTables + 1] = luaArgs
elseif options.parentOnly then
 
table.insert(argTables, pargs)
 
elseif options.parentFirst then
 
table.insert(argTables, pargs)
 
table.insert(argTables, fargs)
 
else
 
table.insert(argTables, fargs)
 
table.insert(argTables, pargs)
 
end
 
table.insert(argTables, luaArgs)
 
  
 
--[[
 
--[[
-- Define metatable behaviour. Arguments are stored in the metaArgs table, and are only fetched from the
+
-- Define metatable behaviour. Arguments are memoized in the metaArgs table, and are only fetched from the
-- argument tables once. Also, we keep a record in the metatable of when pairs and ipairs have been called,
+
-- argument tables once. Nil arguments are also memoized using the nilArg variable in order to increase
-- so we do not run pairs and ipairs on fargs and pargs more than once. We also do not run ipairs on fargs
+
-- performance. Also, we keep a record in the metatable of when pairs and ipairs have been called, so we
-- and pargs if pairs has already been run, as all the arguments will already have been copied over.
+
-- do not run pairs and ipairs on fargs and pargs 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)
 
local val = metaArgs[key]
 
local val = metaArgs[key]
 
if val ~= nil then
 
if val ~= nil then
return val
+
if val == nilArg then
else
+
return nil
for i, argTable in ipairs(argTables) do
+
else
local argTableVal = tidyVal(key, argTable[key])
+
return val
if argTableVal ~= nil then
+
end
metaArgs[key] = argTableVal
+
end
return argTableVal
+
for _, argTable in ipairs(argTables) do
end
+
local argTableVal = tidyVal(key, argTable[key])
 +
if argTableVal == nil then
 +
metaArgs[key] = nilArg
 +
else
 +
metaArgs[key] = argTableVal
 +
return argTableVal
 
end
 
end
 
end
 
end
 +
return nil
 
end
 
end
  
 
metatable.__newindex = function (t, key, val)
 
metatable.__newindex = function (t, key, val)
if not options.readOnly and (not options.noOverwrite or args[key] == nil) then
+
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.
 +
else
 
metaArgs[key] = val
 
metaArgs[key] = val
 
end
 
end

Revision as of 14:06, 11 December 2013

-- 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.

-- 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) if type(val) == 'string' then val = val:match('^%s*(.-)%s*$') if val == then return nil else return val end else return val end end

local function tidyValTrimOnly(key, val) if type(val) == 'string' then return val:match('^%s*(.-)%s*$') else return val end end

local function tidyValRemoveBlanksOnly(key, val) if type(val) == 'string' then if val:find('%S') then return val else return nil end else return val end end

local function tidyValNoChange(key, val) return val end

function arguments.getArgs(frame, options) checkType('getArgs', 1, frame, 'table', true) checkType('getArgs', 2, options, 'table', true) frame = frame or {} options = options or {}

-- Get the arguments from the frame object if available. If the frame object is not available, we are being called -- from another Lua module or from the debug console, so put the args in a special table so we can differentiate them. local fargs, pargs, luaArgs if type(frame.args) == 'table' and type(frame.getParent) == 'function' then if not options.parentOnly then fargs = frame.args end if not options.frameOnly then pargs = frame:getParent().args end if options.parentFirst then fargs, pargs = pargs, fargs end else luaArgs = frame end

-- Set up the args and metaArgs tables. args will be the one accessed from functions, and metaArgs will hold the actual arguments. -- The metatable connects the two together. local args, metaArgs, metatable = {}, {}, {} setmetatable(args, metatable)

-- Generate the tidyVal function. If it has been specified by the user, we 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("bad value assigned to option 'valueFunc' (function expected, got " .. type(tidyVal) .. ')', 2) end elseif options.trim ~= false then if options.removeBlanks ~= false then tidyVal = tidyValDefault else tidyVal = tidyValTrimOnly end else if options.removeBlanks ~= false then tidyVal = tidyValRemoveBlanksOnly else tidyVal = tidyValNoChange 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 precendence. -- 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 local metaArgsVal = metaArgs[key] if metaArgsVal == nil or metaArgsVal == nilArg then local tidiedVal = tidyVal(key, val) if tidiedVal == nil then metaArgs[key] = nilArg else metaArgs[key] = tidiedVal end 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, and are only fetched from the -- argument tables once. Nil arguments are also memoized using the nilArg variable in order to increase -- 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 and -- 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 val ~= nil then if val == nilArg then return nil else 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 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. else metaArgs[key] = val end end

metatable.__pairs = function () if not metatable.donePairs then mergeArgs(pairs, argTables) metatable.donePairs = true metatable.doneIpairs = true end return pairs(metaArgs) end

metatable.__ipairs = function () if not metatable.doneIpairs then mergeArgs(ipairs, argTables) metatable.doneIpairs = true end return ipairs(metaArgs) end

return args end

return arguments