Module:Arguments: Difference between revisions
Content added Content deleted
(Created page with "-- 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 di...") |
(fix undefined next() behaviour bug by checking for metatable.donePairs in the __index metamethod; also, format the module so it fits into 80 characters) |
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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 |
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-- It is intended for use by other Lua modules, and should not be |
-- #invoke. It is intended for use by other Lua modules, and should not be |
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-- called from #invoke directly. |
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local libraryUtil = require('libraryUtil') |
local libraryUtil = require('libraryUtil') |
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local checkType = libraryUtil.checkType |
local checkType = libraryUtil.checkType |
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local arguments = {} |
local arguments = {} |
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local nilArg = {} -- Used for memoizing nil arguments in metaArgs. |
local nilArg = {} -- Used for memoizing nil arguments in metaArgs. |
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-- Generate four different tidyVal functions, so that we don't have to check the |
-- Generate four different tidyVal functions, so that we don't have to check the |
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-- options every time we call it. |
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local function tidyValDefault(key, val) |
local function tidyValDefault(key, val) |
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if type(val) == 'string' then |
if type(val) == 'string' then |
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end |
end |
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end |
end |
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local function tidyValTrimOnly(key, val) |
local function tidyValTrimOnly(key, val) |
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if type(val) == 'string' then |
if type(val) == 'string' then |
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end |
end |
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end |
end |
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local function tidyValRemoveBlanksOnly(key, val) |
local function tidyValRemoveBlanksOnly(key, val) |
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if type(val) == 'string' then |
if type(val) == 'string' then |
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end |
end |
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end |
end |
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local function tidyValNoChange(key, val) |
local function tidyValNoChange(key, val) |
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return val |
return val |
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end |
end |
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function arguments.getArgs(frame, options) |
function arguments.getArgs(frame, options) |
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checkType('getArgs', 1, frame, 'table', true) |
checkType('getArgs', 1, frame, 'table', true) |
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frame = frame or {} |
frame = frame or {} |
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options = options or {} |
options = options or {} |
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--[[ |
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-- Get the arguments from the frame object if available. If the frame object is not available, we are being called |
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-- Get the arguments from the frame object if available. If the frame object |
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-- from another Lua module or from the debug console, so assign the args to a new variable so we can differentiate them. |
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-- is not available, we are being called from another Lua module or from the |
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-- debug console, so assign the args to a new variable so we can |
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-- differentiate them. |
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--]] |
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local fargs, pargs, luaArgs |
local fargs, pargs, luaArgs |
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if type(frame.args) == 'table' and type(frame.getParent) == 'function' then |
if type(frame.args) == 'table' and type(frame.getParent) == 'function' then |
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luaArgs = frame |
luaArgs = frame |
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end |
end |
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-- Set up the args and metaArgs tables. args will be the one accessed from |
-- Set up the args and metaArgs tables. args will be the one accessed from |
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-- functions, and metaArgs will hold the actual arguments. The metatable |
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-- The metatable connects the two together. |
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-- connects the two together. |
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local args, metaArgs, metatable = {}, {}, {} |
local args, metaArgs, metatable = {}, {}, {} |
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setmetatable(args, metatable) |
setmetatable(args, metatable) |
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--[[ |
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-- Generate the tidyVal function. If it has been specified by the user, we use that; if not, we choose one of four functions |
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-- Generate the tidyVal function. If it has been specified by the user, we |
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-- depending on the options chosen. This is so that we don't have to call the options table every time the function is called. |
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-- use that; if not, we choose one of four functions depending on the |
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-- options chosen. This is so that we don't have to call the options table |
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-- every time the function is called. |
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--]] |
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local tidyVal = options.valueFunc |
local tidyVal = options.valueFunc |
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if tidyVal then |
if tidyVal then |
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if type(tidyVal) ~= 'function' then |
if type(tidyVal) ~= 'function' then |
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error( |
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error("bad value assigned to option 'valueFunc' (function expected, got " .. type(tidyVal) .. ')', 2) |
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"bad value assigned to option 'valueFunc'" |
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.. '(function expected, got ' |
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.. type(tidyVal) |
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.. ')', |
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2 |
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) |
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end |
end |
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elseif options.trim ~= false then |
elseif options.trim ~= false then |
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end |
end |
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end |
end |
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local function mergeArgs(iterator, tables) |
local function mergeArgs(iterator, tables) |
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--[[ |
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-- Accepts multiple tables as input and merges their keys and values into one table using the specified iterator. |
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-- Accepts multiple tables as input and merges their keys and values |
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-- If a value is already present it is not overwritten; tables listed earlier have precedence. |
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-- into one table using the specified iterator. If a value is already |
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-- We are also memoizing nil values, but those values can be overwritten. |
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-- present it is not overwritten; tables listed earlier have precedence. |
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-- We are also memoizing nil values, but those values can be |
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-- overwritten. |
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--]] |
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for _, t in ipairs(tables) do |
for _, t in ipairs(tables) do |
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for key, val in iterator(t) do |
for key, val in iterator(t) do |
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end |
end |
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end |
end |
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-- Set the order of precedence of the argument tables. If the variables are |
-- Set the order of precedence of the argument tables. If the variables are |
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-- nil, nothing will be added to the table, which is how we avoid clashes |
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-- which is how we avoid clashes between the frame/parent args and the Lua args. |
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-- between the frame/parent args and the Lua args. |
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local argTables = {fargs} |
local argTables = {fargs} |
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argTables[#argTables + 1] = pargs |
argTables[#argTables + 1] = pargs |
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argTables[#argTables + 1] = luaArgs |
argTables[#argTables + 1] = luaArgs |
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--[[ |
--[[ |
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-- Define metatable behaviour. Arguments are memoized in the metaArgs table, |
-- Define metatable behaviour. Arguments are memoized in the metaArgs table, |
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-- and are only fetched from the argument tables once. Nil arguments are |
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-- argument tables once. Nil arguments are also memoized using the nilArg variable in order to increase |
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-- also memoized using the nilArg variable in order to increase performance. |
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-- performance. Also, we keep a record in the metatable of when pairs and ipairs have been called, so we |
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-- Also, we keep a record in the metatable of when pairs and ipairs have |
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-- do not run pairs and ipairs on fargs and pargs more than once. We also do not run ipairs on fargs and |
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-- been called, so we do not run pairs and ipairs on fargs and pargs more |
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-- pargs if pairs has already been run, as all the arguments will already have been copied over. |
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-- than once. We also do not run ipairs on fargs and pargs if pairs has |
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-- already been run, as all the arguments will already have been copied |
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-- over. |
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--]] |
--]] |
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metatable.__index = function (t, key) |
metatable.__index = function (t, key) |
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local val = metaArgs[key] |
local val = metaArgs[key] |
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if val ~= nil then |
if metatable.donePairs or val ~= nil then |
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--[[ |
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-- We have either memoized the argument already, or pairs has been |
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-- called, meaning that mergeArgs has already copied all of the |
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-- available arguments into the metaArgs table. We need to check for |
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-- pairs as we can't memoize nils to the metaArgs table while pairs |
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-- is iterating. Adding new instances of nilArg to the metaArgs |
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-- table while pairs is iterating over it produces undefined |
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-- behaviour in the next() function. |
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--]] |
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if val == nilArg then |
if val == nilArg then |
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return nil |
return nil |
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return nil |
return nil |
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end |
end |
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metatable.__newindex = function (t, key, val) |
metatable.__newindex = function (t, key, val) |
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if options.readOnly then |
if options.readOnly then |
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error( |
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error('could not write to argument table key "' .. tostring(key) .. '"; the table is read-only', 2) |
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'could not write to argument table key "' |
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.. tostring(key) |
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.. '"; the table is read-only', |
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2 |
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) |
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elseif options.noOverwrite and args[key] ~= nil then |
elseif options.noOverwrite and args[key] ~= nil then |
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error( |
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error('could not write to argument table key "' .. tostring(key) .. '"; overwriting existing arguments is not permitted', 2) |
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'could not write to argument table key "' |
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.. tostring(key) |
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.. '"; overwriting existing arguments is not permitted', |
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2 |
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) |
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elseif val == nil then |
elseif val == nil then |
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metaArgs[key] = nilArg -- Memoize nils. |
metaArgs[key] = nilArg -- Memoize nils. |
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end |
end |
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end |
end |
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metatable.__pairs = function () |
metatable.__pairs = function () |
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if not metatable.donePairs then |
if not metatable.donePairs then |
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end |
end |
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end |
end |
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metatable.__ipairs = function () |
metatable.__ipairs = function () |
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if not metatable.doneIpairs then |
if not metatable.doneIpairs then |
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end, nil, 0 |
end, nil, 0 |
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end |
end |
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return args |
return args |
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end |
end |
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return arguments |
return arguments |