Difference between revisions of "Module:Arguments"
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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
>Mr. Stradivarius (don't use "if frame == mw.getCurrentFrame()") |
>Mr. Stradivarius (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) |
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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) | ||
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 | 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 = | luaArgs = frame | ||
end | end | ||
Line 22: | Line 76: | ||
setmetatable(args, 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 type( | 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 | else | ||
tidyVal = tidyValTrimOnly | |||
end | end | ||
else | |||
if options.removeBlanks ~= false then | |||
tidyVal = tidyValRemoveBlanksOnly | |||
tidyVal = | |||
else | else | ||
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 | ||
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 | ||
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} | ||
argTables[#argTables + 1] = pargs | |||
argTables[#argTables + 1] = luaArgs | |||
--[[ | --[[ | ||
-- Define metatable behaviour. Arguments are | -- 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 | ||
-- | -- 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) | 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 | ||
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 | ||
end | end | ||
return nil | |||
end | end | ||
metatable.__newindex = function (t, key, val) | metatable.__newindex = function (t, key, val) | ||
if | 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 |