Difference between revisions of "Module:Hatnote list"

Revision as of 08:25, 5 May 2016

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--                           Module:Hatnote list                              --
--                                                                            --
-- This module produces and formats lists for use in hatnotes. In particular, --
-- it implements the for-see list, i.e. lists of "For X, see Y" statements,   --
-- as used in {{about}}, {{redirect}}, and their variants. Also introduced    --
-- are andList & orList helpers for formatting lists with those conjunctions. --
--------------------------------------------------------------------------------

local mArguments --initialize lazily
local mHatnote = require('Module:Hatnote')
local libraryUtil = require('libraryUtil')
local checkType = libraryUtil.checkType
local p = {}

--------------------------------------------------------------------------------
-- List stringification helper functions
--
-- These functions are used for stringifying lists, usually page lists inside
-- the "Y" portion of "For X, see Y" for-see items.
--------------------------------------------------------------------------------

--default options table used across the list stringification functions
local stringifyListDefaultOptions = {
	conjunction = "and",
	separator = ",",
	altSeparator = ";",
	space = " "
}

-- Stringifies a list generically; probably shouldn't be used directly
function stringifyList(list, options)
	-- Type-checks, defaults, and a shortcut
	checkType("stringifyList", 1, list, "table")
	if #list == 0 then return nil end
	checkType("stringifyList", 2, options, "table", true)
	options = options or {}
	for k, v in pairs(stringifyListDefaultOptions) do
		if options[k] == nil then options[k] = v end
	end
	local s = options.space
	-- Set the separator; if any item contains it, use the alternate separator
	local separator = options.separator
	for k, v in pairs(list) do
		if string.find(v, separator) then
			separator = options.altSeparator
			break
		end
	end
	-- Set the conjunction, apply Oxford comma, and force a comma if #1 has "§"
	local conjunction = s .. options.conjunction .. s
	if #list == 2 and string.find(list[1], "§") or #list > 2 then
		conjunction = separator .. conjunction
	end
	-- Return the formatted string
	return mw.text.listToText(list, separator .. s, conjunction)
end

-- Stringifies a list with "and"
function p.andList (list)
	return stringifyList(list, {conjunction = "and"})
end

-- Stringifies a list with "or"
function p.orList (list)
	return stringifyList(list, {conjunction = "or"})
end

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-- For see
--
-- Makes a "For X, see [[Y]]." list from raw parameters. Intended for the
-- {{about}} and {{redirect}} templates and their variants.
--------------------------------------------------------------------------------

--default options table used across the forSee family of functions
local forSeeDefaultOptions = {
	disambiguator = ' (disambiguation)',
	title = mw.title.getCurrentTitle().text,
	otherText = 'other uses',
	forseeForm = 'For %s, see %s.',
	punctuationCollapseReplacements = {
		["%.%.$"] = ".",
		["%?%.$"] = "?",
		["%!%.$"] = "!",
		["%.%]%]%.$"] = ".]]",
		["%?%]%]%.$"] = "?]]",
		["%!%]%]%.$"] = "!]]"
	}
}

-- Structures arguments into a table for stringification, & options
function p.forSeeArgsToTable (args, from, options)
	-- Type-checks and defaults
	checkType("forSeeArgsToTable", 1, args, 'table')
	checkType("forSeeArgsToTable", 2, from, 'number', true)
	from = from or 1
	checkType("forSeeArgsToTable", 3, options, 'table', true)
	options = options or {}
	for k, v in pairs(forSeeDefaultOptions) do
		if options[k] == nil then options[k] = v end
	end
	-- maxArg's gotten manually because getArgs() and table.maxn aren't friends
	local maxArg = 0
	for k, v in pairs(args) do
		if type(k) == 'number' and k > maxArg then maxArg = k end
	end
	-- Structure the data out from the parameter list
	-- forTable is the wrapper table, with forRow rows
	-- Rows are tables of a "use" string and a "pages" table of pagename strings
	local forTable = {}
	local i = from
	local terminated = false
	-- Repeat to generate and append each row
	repeat
		-- New empty row
		local forRow = {}
		-- If there's a blank use, assume the list's ended, use the default,
		-- and break at the end of this loop-through.
		forRow.use = args[i] or options.otherText
		if not args[i] then terminated = true end
		-- New empty list of pages
		forRow.pages = {}
		-- If there's not at least one page listed, use the default.
		table.insert(forRow.pages, args[i + 1] or (options.title .. options.disambiguator))
		-- If the option after next is "and", do an inner loop where we collect
		-- items following "and"'s until the "and"'s stop. If there's a blank
		-- where we'd expect an item, ignore it: "1|and||and|3" → {1, 3}
		while args[i + 2] == 'and' do
			if args[i + 3] then 
				table.insert(forRow.pages, args[i + 3])
			end
			-- Increment to the next "and"
			i = i + 2
		end
		-- Increment to the next use
		i = i + 2
		-- Add the row to the table
		table.insert(forTable, forRow)
	until terminated or i > maxArg
	
	return forTable
end

-- Takes a table as formatted by forSeeArgsToTable and stringifies it
function p.forSeeTableToString (forSeeTable, options)
	-- Type-checks and defaults
	checkType("forSeeTableToString", 1, forSeeTable, "table")
	checkType("forSeeTableToString", 2, options, "table", true)
	options = options or {}
	for k, v in pairs(forSeeDefaultOptions) do
		if options[k] == nil then options[k] = v end
	end
	-- Format each for-see item and make a table containing them
	local strList = {}
	for k, v in pairs(forSeeTable) do
		local useStr = v.use or options.otherText
		local pagesStr = p.andList(mHatnote.formatPages(unpack(v.pages))) or
			mHatnote._formatLink(options.title .. options.disambiguator)
		local forSeeStr = string.format(options.forseeForm, useStr, pagesStr)
		for k, v in pairs(options.punctuationCollapseReplacements) do
			forSeeStr = string.gsub(forSeeStr, k, v)
		end
		table.insert(strList, forSeeStr)
	end
	-- Return the concatenated list
	return table.concat(strList, ' ')
end

-- Produces a "For X, see [[Y]]" string from arguments. Expects index gaps
-- but not blank or whitespace values; those should be filtered. Ignores
-- arguments less than "from", and named arguments.
function p._forSee (args, from, options)
	local forSeeTable = p.forSeeArgsToTable(args, from, options)
	return p.forSeeTableToString(forSeeTable, options)
end

-- Calls _forSee but pulls from the frame.
function p.forSee (frame, from, options)
	mArguments = require('Module:Arguments')
	return p._forSee(mArguments.getArgs(frame), from, options)
end

return p