Content deleted Content added
m tweak one of the comments and make some beautification fixes, now that this is in the job queue |
fix undefined next() behaviour bug by checking for metatable.donePairs in the __index metamethod; also, format the module so it fits into 80 characters |
||
Line 1:
-- 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')
Line 9 ⟶ 10:
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)
Line 54 ⟶ 56:
options = options or {}
--[[
-- Get the arguments from the frame object if available. If the frame object
-- from another Lua module or from the debug console, so assign the args to a new variable so we can differentiate them.▼
-- is not available, we are being called from another Lua module or from the
▲ --
-- differentiate them.
--]]
local fargs, pargs, luaArgs
if type(frame.args) == 'table' and type(frame.getParent) == 'function' then
Line 71 ⟶ 77:
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 --
local args, metaArgs, metatable = {}, {}, {}
setmetatable(args, metatable)
--[[
-- 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
▲ --
-- every time the function is called.
--]]
local tidyVal = options.valueFunc
if tidyVal then
if type(tidyVal) ~= 'function' then
error(
.. '(function expected, got '
.. type(tidyVal)
.. ')',
2
)
end
elseif options.trim ~= false then
Line 98 ⟶ 115:
local function mergeArgs(iterator, tables)
--[[
-- Accepts multiple tables as input and merges their keys and values
-- If a value is already present it is not overwritten; tables listed earlier have precedence.▼
-- into one table using the specified iterator. If a value is already
-- We are also memoizing nil values, but those values can be overwritten.▼
-- overwritten.
--]]
for _, t in ipairs(tables) do
for key, val in iterator(t) do
Line 116 ⟶ 137:
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 --
local argTables = {fargs}
argTables[#argTables + 1] = pargs
Line 123 ⟶ 145:
--[[
-- 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. --
-- 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 --
-- over. --]]
metatable.__index = function (t, key)
local val = metaArgs[key]
if metatable.donePairs or val ~= nil then
--[[
-- We have either memoized the argument already, or pairs has been
-- called, meaning that mergeArgs has already copied all of the
-- available arguments into the metaArgs table. We need to check for
-- pairs as we can't memoize nils to the metaArgs table while pairs
-- is iterating. Adding new instances of nilArg to the metaArgs
-- table while pairs is iterating over it produces undefined
-- behaviour in the next() function.
--]]
if val == nilArg then
return nil
Line 153 ⟶ 187:
metatable.__newindex = function (t, key, val)
if options.readOnly then
error(
.. 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)
▲
2
)
elseif val == nil then
metaArgs[key] = nilArg -- Memoize nils.
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