require('strict');  
local error_msg = '<span style=\"font-size:100%\" class=\"error\"><code style=\"color:inherit; :inherit; padding:inherit;\">&#124;_template=</code> missing or empty</span>';  
----------------------------< I S _ I N _ T A B L E >--------------------------------------------------------  
scan through tbl looking for value; return true if found, false else  
local function is_in_table (tbl, value)
for k, v in pairs (tbl) do
if v == value then return true end
end
return false;
end  
----------------------------< A D D _ P A R A M E T E R >----------------------------------------------------  
adds parameter name and its value to args table according to the state of boolean list argument; kv pair for
template execution; k=v string for template listing.  
local function add_parameter (k, v, args, list)
if list then
table.insert( args, table.concat ({k, '=', v})); -- write parameter names and values to args table as string
else
args[k] = v; -- copy parameters to args table
end
end  
--[[--------------------------< A L I A S _ M A P _ G E T >----------------------------------------------------  
returns a table of local template (parent ) parameter names and the target template names that match where
in [key]=<value> pairs where:
[key] is local template parameter name (an alias)
<value> is target template parameter name (the canonical parameter name used in the working template)  
The parameter |_alias-map= has the form:
|_alias-map=<list>
where <list> is a comma-separated list of alias / canonical parameter name pairs in the form
<from> : <to>
where:
<from> is the local template's parameter name (alias)
<to> is the target template's parameter name (canonical)
for enumerated parameters place an octothorp (#) where the enumerator digits are placed in the parameter names:
<from#> : <to#>  
local function alias_map_get (_alias_map)
local T = mw.text.split (_alias_map, '%s*,%s*'); -- convert the comma-separated list into a table of alias pairs
local mapped_aliases = {}; -- mapped aliases will go here
local l_name, t_name; -- parameter names  
for _, alias_pair in ipairs (T) do -- loop through the table of alias pairs
l_name, t_name = alias_pair:match ('(.-)%s*:%s*(.+)'); -- from each pair, get local and target parameter names
if l_name and t_name then -- if both are set
if tonumber (l_name) then
l_name = tonumber (l_name); -- convert number-as-text to a number
end
mapped_aliases[l_name] = t_name; -- add them to the map table
end
end  
return mapped_aliases;
end  
--_template= parameter (name of the working template); nil else  
local function frame_args_get (frame_args, args, list)
local template;  
for k, v in pairs (frame_args) do -- here we get the wrapper template's 'default' parameters
if 'string' == type (k) and (v and ('' ~= v)) then -- do not pass along positional or empty parameters
if '_template' == k then
template = v; -- save the name of template that we are wrapping
elseif '_exclude' ~= k and '_reuse' ~= k and '_include-positional' ~= k and '_alias-map' ~= k then -- these already handled so ignore here;
add_parameter (k, v, args, list); -- add all other parameters to args in the style dictated by list
end
end
end  
return template; -- return contents of |_template= parameter
end  
--[=[--------------------------< P F R A M E _ A R G S _ G E T >------------------------------------------------  
Fetches the wrapper template's 'live' parameters; adds live parameters that aren't members of the exclude table to
args table; positional parameters may not be excluded  
no return value  
]=]  
local function pframe_args_get (pframe_args, args, exclude, _include_positional, list)
for k, v in pairs (pframe_args) do
if 'string' == type (k) and not is_in_table (exclude, k) then -- do not pass along excluded parameters
if v and ('' ~= v) then -- pass along only those parameters that have assigned values
if 'unset' == v:lower then -- special keyword to unset 'default' parameters set in the wrapper template
v = ''; -- unset the value in the args table
end
add_parameter (k, v, args, list) -- add all other parameters to args in the style dictated by list; alias map only supported for local-template parameters
end
end
end  
if _include_positional then
for i, v in ipairs (pframe_args) do -- pass along positional parameters
if 'unset' == v:lower then -- special keyword to unset 'default' parameters set in the wrapper template
v = ''; -- unset the value in the args table
end
add_parameter (i, v, args, list);
end
end
end  
----------------------------< _ M A I N >--------------------------------------------------------------------  
Collect the various default and live parameters into args styled according to boolean list.  
returns name of the working or listed template or nil for an error message  
local function _main (, args, list)
local template;
local exclude = {}; -- table of parameter names for parameters that are not passed to the working template
local reuse_list = {}; -- table of pframe parameter names whose values are modified before they are passed to the working template as the same name
local alias_map = {}; -- table that maps parameter aliases to working template canonical parameter names
local _include_positional;  
if .args._exclude and ('' ~= .args._exclude) then -- if there is |_exclude= and it's not empty
exclude = mw.text.split (.args._exclude, "%s*,%s*"); -- make a table from its contents
end
-- TODO: |_reuse= needs a better name (|_reuse=)
if .args._reuse and ('' ~= .args._reuse) then -- if there is |_reuse= and it's not empty
reuse_list = mw.text.split (.args._reuse, "%s*,%s*"); -- make a table from its contents
end  
if .args['_alias-map'] and ('' ~= .args['_alias-map']) then -- if there is |_alias-map= and it's not empty
alias_map = alias_map_get (.args['_alias-map']); -- make a table from its contents
end  
template = frame_args_get (.args, args, list); -- get parameters provided in the
if nil == template or '' == template then -- this is the one parameter that is required by this module
return nil; -- not present, tell calling function to emit an error message
end  
_include_positional = 'yes' == .args['_include-positional']; -- when true pass all positional parameters along with non-excluded named parameters to ...
-- ... the working template; positional parameters are not excludable  
local _pframe_args = :getParent.args; -- here we get the wrapper template's 'live' parameters from pframe.args
local pframe_args = {}; -- a local table that we can modify  
for k, v in pairs (_pframe_args) do -- make a copy that we can modify
pframe_args[k] = v;
end  
-- here we look for pframe parameters that are aliases of canonical parameter names; when found
-- we replace the alias with the canonical. We do this here because the reuse_list works on
-- canonical parameter names so first we convert alias parameter names to canonical names and then
-- we remove those canonical names from the pframe table that are reused (provided to the working
-- template through the args table)  
for k, v in pairs (alias_map) do -- k is alias name, v is canonical name
if pframe_args[k] then -- if pframe_args has parameter with alias name
pframe_args[v] = _pframe_args[k]; -- create new canonical name with alias' value
pframe_args[k] = nil; -- unset the alias
end
end  
for k, v in pairs (pframe_args) do -- do enumerated parameter alias -> canonical translation
if 'string' == type (k) then -- only named parameters can be enumerated
if alias_map[k..'#'] then -- non-enumerated alias matches enumerated parameter pattern? enumerator at end only
pframe_args[alias_map[k..'#']:gsub('#', '')] = v; -- remove '#' and copy parameter to pframe_args table
pframe_args[k] = nil; -- unset the alias
elseif k:match ('%d+') then -- if this parameter name contains digits
local temp = k:gsub ('%d+', '#'); -- make a copy; digits replaced with single '#'
local enum = k:match ('%d+'); -- get the enumerator