Module:parse utilities

local export = {}

local m_string_utilities = require("Module:string utilities") local parameters_module = "Module:parameters"

local rfind = mw.ustring.find local rsplit = mw.text.split local u = mw.ustring.char local rsubn = mw.ustring.gsub

-- version of rsubn that discards all but the first return value local function rsub(term, foo, bar) local retval = rsubn(term, foo, bar) return retval end

--[==[ intro: In order to understand the following parsing code, you need to understand how inflected text specs work. They are intended to work with inflected text where individual words to be inflected may be followed by inflection specs in angle brackets. The format of the text inside of the angle brackets is up to the individual language and part-of-speech specific implementation. A real-world example is as follows: ` меди́чна<+> сестра́<*,*#.pr> `. This is the inflection of the Ukrainian multiword expression , consisting of two words: the adjective and the noun. The specs in angle brackets follow each word to be inflected; for example, `<+>` means that the preceding word should be declined as an adjective.

The code below works in terms of balanced expressions, which are bounded by delimiters such as `< >` or `[ ]`. The intention is to allow separators such as spaces to be embedded inside of delimiters; such embedded separators will not be parsed as separators. For example, Ukrainian noun specs allow footnotes in brackets to be inserted inside of angle brackets; something like `меди́чна<+> сестра́` is legal, as is ` меди́чна<+> сестра́ `, and the parsing code should not be confused by the embedded brackets, spaces or angle brackets.

The parsing is done by two functions, which work in close concert: {parse_balanced_segment_run} and {split_alternating_runs}. To illustrate, consider the following:

{parse_balanced_segment_run("foo bar", "<", ">")} =

{ {"foo", "", " bar", "", ""}}

then

{split_alternating_runs({"foo", "", " bar", "", ""}, " ")} =

{ {{"foo", "", ""}, {"bar", "", ""}}}

Here, we start out with a typical inflected text spec `foo bar`, call {parse_balanced_segment_run} on it, and call {split_alternating_runs} on the result. The output of {parse_balanced_segment_run} is a list where even-numbered segments are bounded by the bracket-like characters passed into the function, and odd-numbered segments consist of the surrounding text. {split_alternating_runs} is called on this, and splits only the odd-numbered segments, grouping all segments between the specified character. Note that the inner lists output by {split_alternating_runs} are themselves in the same format as the output of {parse_balanced_segment_run}, with bracket-bounded text in the even-numbered segments. Hence, such lists can be passed again to {split_alternating_runs}. ]==]

--[==[ Parse a string containing matched instances of parens, brackets or the like. Return a list of strings, alternating between textual runs not containing the open/close characters and runs beginning and ending with the open/close characters. For example,

{parse_balanced_segment_run("foo(x(1)), bar(2)", "(", ")") = {"foo", "(x(1))", ", bar", "(2)", ""}} ]==] function export.parse_balanced_segment_run(segment_run, open, close) return m_string_utilities.split(segment_run, "(%b" .. open .. close .. ")") end

-- The following is an equivalent, older implementation that does not use %b (written before I was aware of %b). --[=[ function export.parse_balanced_segment_run(segment_run, open, close) local break_on_open_close = m_string_utilities.split(segment_run, "([%" .. open .. "%" .. close .. "])")	local text_and_specs = {} local level = 0 local seg_group = {} for i, seg in ipairs(break_on_open_close) do		if i % 2 == 0 then if seg == open then table.insert(seg_group, seg) level = level + 1 else assert(seg == close) table.insert(seg_group, seg) level = level - 1 if level < 0 then error("Unmatched " .. close .. " sign: '" .. segment_run .. "'") elseif level == 0 then table.insert(text_and_specs, table.concat(seg_group)) seg_group = {} end end elseif level > 0 then table.insert(seg_group, seg) else table.insert(text_and_specs, seg) end end if level > 0 then error("Unmatched " .. open .. " sign: '" .. segment_run .. "'") end return text_and_specs end ]=]

--[==[ Like parse_balanced_segment_run but accepts multiple sets of delimiters. For example,

{parse_multi_delimiter_balanced_segment_run("foo[bar(baz[bat])], quux ", {{"[", "]"}, {"(", ")"}, {"<", ">"}}) = {"foo", "[bar(baz[bat])]", ", quux", " ", ""}}.

Each element in the list of delimiter pairs is a string specifying an equivalence class of possible delimiter characters. You can use this, for example, to allow either "[" or "&amp;#91;" to be treated equivalently, with either one closed by either "]" or "&amp;#93;". To do this, first replace "&amp;#91;" and "&amp;#93;" with single Unicode characters such as U+FFF0 and U+FFF1, and then specify a two-character string containing "[" and U+FFF0 as the opening delimiter, and a two-character string containing "]" and U+FFF1 as the corresponding closing delimiter.

If `no_error_on_unmatched` is given and an error is found during parsing, a string is returned containing the error message instead of throwing an error. ]==] function export.parse_multi_delimiter_balanced_segment_run(segment_run, delimiter_pairs, no_error_on_unmatched) local escaped_delimiter_pairs = {} local open_to_close_map = {} local open_close_items = {} local open_items = {} for _, open_close in ipairs(delimiter_pairs) do		local open, close = unpack(open_close) open = rsub(open, "([%[%]%%%%-])", "%%%1") close = rsub(close, "([%[%]%%%%-])", "%%%1") table.insert(open_close_items, open) table.insert(open_close_items, close) table.insert(open_items, open) open = "[" .. open .. "]"		close = "[" .. close .. "]"		open_to_close_map[open] = close table.insert(escaped_delimiter_pairs, {open, close}) end local open_close_pattern = "([" .. table.concat(open_close_items) .. "])" local open_pattern = "([" .. table.concat(open_items) .. "])" local break_on_open_close = m_string_utilities.split(segment_run, open_close_pattern) local text_and_specs = {} local level = 0 local seg_group = {} local open_at_level_zero

for i, seg in ipairs(break_on_open_close) do		if i % 2 == 0 then table.insert(seg_group, seg) if level == 0 then if not rfind(seg, open_pattern) then local errmsg = "Unmatched close sign " .. seg .. ": '" .. segment_run .. "'"					if no_error_on_unmatched then return errmsg else error(errmsg) end end assert(open_at_level_zero == nil) for _, open_close in ipairs(escaped_delimiter_pairs) do					local open, close = unpack(open_close) if rfind(seg, open) then open_at_level_zero = open break end end if open_at_level_zero == nil then error(("Internal error: Segment %s didn't match any open regex"):format(seg)) end level = level + 1 elseif rfind(seg, open_at_level_zero) then level = level + 1 elseif rfind(seg, open_to_close_map[open_at_level_zero]) then level = level - 1 assert(level >= 0) if level == 0 then table.insert(text_and_specs, table.concat(seg_group)) seg_group = {} open_at_level_zero = nil end end elseif level > 0 then table.insert(seg_group, seg) else table.insert(text_and_specs, seg) end end if level > 0 then local errmsg = "Unmatched open sign " .. open_at_level_zero .. ": '" .. segment_run .. "'"		if no_error_on_unmatched then return errmsg else error(errmsg) end end return text_and_specs end

--[==[ Check whether a term contains top-level HTML. We want to distinguish inline modifiers from HTML. We assume an inline modifier is either a boolean modifier like ` ` or a prefix modifier like ``. All other things inside of angle brackets, e.g. ` `, `   `, `   `, etc., should be flagged as HTML (typically caused by wrapping an argument in ..., ... or similar, but sometimes specified directly, e.g. ` 6 `). By default, we assume the tag in an inline modifier contains either letters, numbers, hyphens or underscore (but not spaces), and must either stand alone or be followed by a colon, leading to a default HTML-checking pattern of {"<[%w_%-]*[^%w_%-:>]"}. But this can be modified; e.g. Module:tl-pronunciation allows modifiers of the form `< pos ^ defn >` or `< pos, pos , pos ^ defn >`, and would need to use its own HTML pattern. It's important we restrict the check for HTML to top-level to allow for generated HTML inside of e.g. qualifier tags, such as ` foo `. ]==] function export.term_contains_top_level_html(term, html_pattern) html_pattern = html_pattern or "<[%w_%-]*[^%w_%-:>]" -- If no HTML anywhere, the answer is no.	if not term:find(html_pattern) then return false end -- Otherwise, we have to call parse_balanced_segment_run and check alternate runs at top level. local runs = export.parse_balanced_segment_run(term, "<", ">") for i = 2, #runs, 2 do if runs[i]:find("^" .. html_pattern) then return true end end return false end

--[==[ Split a list of alternating textual runs of the format returned by `parse_balanced_segment_run` on `splitchar`. This only splits the odd-numbered textual runs (the portions between the balanced open/close characters). The return value is a list of lists, where each list contains an odd number of elements, where the even-numbered elements of the sublists are the original balanced textual run portions. For example, if we do

{parse_balanced_segment_run("foo bar", "<", ">") = {"foo", "<M.proper noun>", " bar", "<F>", ""}}

then

{split_alternating_runs({"foo", "<M.proper noun>", " bar", "<F>", ""}, " ") = {{"foo", "<M.proper noun>", ""}, {"bar", "<F>", ""}}}

Note that we did not touch the text "<M.proper noun>" even though it contains a space in it, because it is an even-numbered element of the input list. This is intentional and allows for embedded separators inside of brackets/parens/etc. Note also that the inner lists in the return value are of the same form as the input list (i.e. they consist of alternating textual runs where the even-numbered segments are balanced runs), and can in turn be passed to split_alternating_runs.

If `preserve_splitchar` is passed in, the split character is included in the output, as follows:

{split_alternating_runs({"foo", "<M.proper noun>", " bar", "<F>", ""}, " ", true) = {{"foo", "<M.proper noun>", ""}, {" "}, {"bar", "<F>", ""}}}

Consider what happens if the original string has multiple spaces between brackets, and multiple sets of brackets without spaces between them.

{parse_balanced_segment_run("foo[dated][low colloquial] baz-bat quux xyzzy[archaic]", "[", "]") = {"foo", "[dated]", "", "[low colloquial]", " baz-bat quux xyzzy", "[archaic]", ""}}

then

{split_alternating_runs({"foo", "[dated]", "", "[low colloquial]", " baz-bat quux xyzzy", "[archaic]", ""}, "[ %-]") = {{"foo", "[dated]", "", "[low colloquial]", ""}, {"baz"}, {"bat"}, {"quux"}, {"xyzzy", "[archaic]", ""}}}

If `preserve_splitchar` is passed in, the split character is included in the output, as follows:

{split_alternating_runs({"foo", "[dated]", "", "[low colloquial]", " baz bat quux xyzzy", "[archaic]", ""}, "[ %-]", true) = {{"foo", "[dated]", "", "[low colloquial]", ""}, {" "}, {"baz"}, {"-"}, {"bat"}, {" "}, {"quux"}, {" "}, {"xyzzy", "[archaic]", ""}}}

As can be seen, the even-numbered elements in the outer list are one-element lists consisting of the separator text. ]==] function export.split_alternating_runs(segment_runs, splitchar, preserve_splitchar) local grouped_runs = {} local run = {} for i, seg in ipairs(segment_runs) do		if i % 2 == 0 then table.insert(run, seg) else local parts = preserve_splitchar and m_string_utilities.split(seg, "(" .. splitchar .. ")") or				rsplit(seg, splitchar) table.insert(run, parts[1]) for j=2,#parts do				table.insert(grouped_runs, run) run = {parts[j]} end end end if #run > 0 then table.insert(grouped_runs, run) end return grouped_runs end

function export.strip_spaces(text) return rsub(text, "^%s*(.-)%s*$", "%1") end

--[==[ Apply an arbitrary function `frob` to the "raw-text" segments in a split run set (the output of split_alternating_runs). We leave alone stuff within balanced delimiters (footnotes, inflection specs and the like), as well as splitchars themselves if present. `preserve_splitchar` indicates whether splitchars are present in the split run set. `frob` is a function of one argument (the string to frob) and should return one argument (the frobbed string). We operate by only frobbing odd-numbered segments, and only in odd-numbered runs if preserve_splitchar is given. ]==] function export.frob_raw_text_alternating_runs(split_run_set, frob, preserve_splitchar) for i, run in ipairs(split_run_set) do		if not preserve_splitchar or i % 2 == 1 then for j, segment in ipairs(run) do				if j % 2 == 1 then run[j] = frob(segment) end end end end end

--[==[ Like split_alternating_runs but applies an arbitrary function `frob` to "raw-text" segments in the result (i.e. not stuff within balanced delimiters such as footnotes and inflection specs, and not splitchars if present). `frob` is a function of one argument (the string to frob) and should return one argument (the frobbed string). ]==] function export.split_alternating_runs_and_frob_raw_text(run, splitchar, frob, preserve_splitchar) local split_runs = export.split_alternating_runs(run, splitchar, preserve_splitchar) export.frob_raw_text_alternating_runs(split_runs, frob, preserve_splitchar) return split_runs end

--[==[ Split the non-modifier parts of an alternating run (after parse_balanced_segment_run is called) on a Lua pattern, but not on certain sequences involving characters in that pattern (e.g. comma+whitespace). `splitchar` is the pattern to split on; `preserve_splitchar` indicates whether to preserve the delimiter and is the same as in split_alternating_runs. `escape_fun` is called beforehand on each run of raw text and should return two values: the escaped run and whether unescaping is needed. If any call to `escape_fun` indicates that unescaping is needed, `unescape_fun` will be called on each run of raw text after splitting on `splitchar`. The return value of this function is as in split_alternating_runs. ]==] function export.split_alternating_runs_escaping(run, splitchar, preserve_splitchar, escape_fun, unescape_fun) -- First replace comma with a temporary character in comma+whitespace sequences. local need_unescape = false for i, seg in ipairs(run) do		if i % 2 == 1 then local this_need_unescape run[i], this_need_unescape = escape_fun(run[i]) need_unescape = need_unescape or this_need_unescape end end

if need_unescape then return export.split_alternating_runs_and_frob_raw_text(run, splitchar, unescape_fun, preserve_splitchar) else return export.split_alternating_runs(run, splitchar, preserve_splitchar) end end

--[==[ Replace comma with a temporary char in comma + whitespace. ]==] function export.escape_comma_whitespace(run, tempcomma) tempcomma = tempcomma or u(0xFFF0) local escaped = false

if run:find("\\,") then run = run:gsub("\\,", "\\" .. tempcomma) -- assign to temp to discard second return value escaped = true end if run:find(",%s") then run = run:gsub(",(%s)", tempcomma .. "%1") -- assign to temp to discard second return value escaped = true end return run, escaped end

--[==[ Undo the replacement of comma with a temporary char. ]==] function export.unescape_comma_whitespace(run, tempcomma) tempcomma = tempcomma or u(0xFFF0)

run = run:gsub(tempcomma, ",") -- assign to temp to discard second return value return run end

--[==[ Split the non-modifier parts of an alternating run (after parse_balanced_segment_run is called) on comma, but not on comma+whitespace. See `split_on_comma` above for more information and the meaning of `tempcomma`. ]==] function export.split_alternating_runs_on_comma(run, tempcomma) tempcomma = tempcomma or u(0xFFF0)

-- Replace comma with a temporary char in comma + whitespace. local function escape_comma_whitespace(seg) return export.escape_comma_whitespace(seg, tempcomma) end

-- Undo replacement of comma with a temporary char in comma + whitespace. local function unescape_comma_whitespace(seg) return export.unescape_comma_whitespace(seg, tempcomma) end

return export.split_alternating_runs_escaping(run, ",", false, escape_comma_whitespace, unescape_comma_whitespace) end

--[==[ Split text on a Lua pattern, but not on certain sequences involving characters in that pattern (e.g. comma+whitespace). `splitchar` is the pattern to split on; `preserve_splitchar` indicates whether to preserve the delimiter between split segments. `escape_fun` is called beforehand on the text and should return two values: the escaped run and whether unescaping is needed. If the call to `escape_fun` indicates that unescaping is needed, `unescape_fun` will be called on each run of text after splitting on `splitchar`. The return value of this a list of runs, interspersed with delimiters if `preserve_splitchar` is specified. ]==] function export.split_escaping(text, splitchar, preserve_splitchar, escape_fun, unescape_fun) if not rfind(text, splitchar) then return {text} end

-- If there are square or angle brackets, we don't want to split on delimiters inside of them. To effect this, we	-- use parse_multi_delimiter_balanced_segment_run to parse balanced brackets, then do delimiter splitting on the -- non-bracketed portions of text using split_alternating_runs_escaping, and concatenate back to a list of -- strings. When calling parse_multi_delimiter_balanced_segment_run, we make sure not to throw an error on -- unbalanced brackets; in that case, we fall through to the code below that handles the case without brackets. if text:find("[%[<]") then local runs = export.parse_multi_delimiter_balanced_segment_run(text, {{"[", "]"}, {"<", ">"}},			"no error on unmatched") if type(runs) ~= "string" then local split_runs = export.split_alternating_runs_escaping(runs, splitchar, preserve_splitchar, escape_fun,				unescape_fun) for i = 1, #split_runs, (preserve_splitchar and 2 or 1) do				split_runs[i] = table.concat(split_runs[i]) end return split_runs end end

-- First escape sequences we don't want to count for splitting. local need_unescape text, need_unescape = escape_fun(text)

local parts = preserve_splitchar and m_string_utilities.split(text, "(" .. splitchar .. ")") or		rsplit(text, splitchar) if need_unescape then for i = 1, #parts, (preserve_splitchar and 2 or 1) do			parts[i] = unescape_fun(parts[i]) end end return parts end

--[==[ Split text on comma, but not on comma+whitespace. This is similar to `mw.text.split(text, ",")` but will not split on commas directly followed by whitespace, to handle embedded commas in terms (which are almost always followed by a space). `tempcomma` is the Unicode character to temporarily use when doing the splitting; normally U+FFF0, but you can specify a different character if you use U+FFF0 for some internal purpose. ]==] function export.split_on_comma(text, tempcomma) -- Don't do anything if no comma. Note that split_escaping has a similar check at the beginning, so if there's a	-- comma we effectively do this check twice, but this is worth it to optimize for the common no-comma case. if not text:find(",") then return {text} end

tempcomma = tempcomma or u(0xFFF0)

-- Replace comma with a temporary char in comma + whitespace. local function escape_comma_whitespace(run) return export.escape_comma_whitespace(run, tempcomma) end

-- Undo replacement of comma with a temporary char in comma + whitespace. local function unescape_comma_whitespace(run) return export.unescape_comma_whitespace(run, tempcomma) end

return export.split_escaping(text, ",", false, escape_comma_whitespace, unescape_comma_whitespace) end

--[==[ Ensure that Wikicode (bracketed links, HTML, bold/italics, etc.) displays literally in error messages by inserting a Unicode word-joiner symbol after all characters that may trigger Wikicode interpr. Replacing with equivalent HTML escapes doesn't work because they are displayed literally. I could not get this to work using ... (those tags display literally) and using using (same thing). FIXME: This is a massive hack; there must be a better way. ]==] function export.escape_wikicode(term) term = term:gsub("([%[<'])", "%1" .. u(0x2060)) return term end

function export.make_parse_err(arg_gloss) return function(msg, stack_frames_to_ignore) error(export.escape_wikicode(("%s: %s"):format(msg, arg_gloss)), stack_frames_to_ignore) end end

-- Parse a term that may include a link 'LINK' or a two-part link 'DISPLAY'. FIXME: Doesn't currently -- handle embedded links like 'FOO BAR' or BAR BAZ' or 'FOOs'; if they are detected, it returns -- the term unchanged and `nil` for the display form. local function parse_bracketed_term(term, parse_err) local inside = term:match("^%[%[(.*)%]%]$") if inside then if inside:find("%[%[") or inside:find("%]%]") then -- embedded links, e.g. 'FOO BAR'; FIXME: we should process them properly return term, nil end local parts = rsplit(inside, "|") if #parts > 2 then parse_err("Saw more than two parts inside a bracketed link") end return unpack(parts) end return term, nil end

--[==[ Parse a term that may have a language code (or possibly multiple comma-separated language codes, if `allow_multiple` is given) preceding it (e.g. {la:minūtia} or {grc:σκατός} or {nan-hbl,hak:毋知}). Return four arguments: list of such objects if `allow_multiple` is given; Wikipedia and Wikisource prefixes) or of the form {{ link }, otherwise the full term; Etymology-only languages are allowed. This function also correctly handles Wikipedia prefixes (e.g. {w:Abatemarco} or {w:it:Colle Val d'Elsa} or {lw:ru:Филарет}) and Wikisource prefixes (e.g. {s:Twelve O'Clock} or {s:Walden} or {s:fr:Perceval ou le conte du Graal} or {s:ro:Mr. Vucea} or {ls:ko:이상적 부인} or {ls:ko:조선 독립의 서}) and converts them into two-part links, with the display form not including the Wikipedia or Wikisource prefix unless it was explicitly specified using a two-part link as in {lw:ru:Митрополи́т Филаре́т} or {ls:ko:조선 독립의 서}. The difference between {w:} ("Wikipedia") and {lw:} ("Wikipedia link") is that the latter requires a language code and returns the corresponding language object; same for the difference between {s:} ("Wikisource") and {ls:} ("Wikisource link").
 * 1) the term minus the language code;
 * 2) the language object corresponding to the language code (possibly a family object if `allow_family` is given), or a
 * 1) the link if the term is of the form { display } (it may be generated into that form with
 * 1) the display part if the term is of the form { display }, otherwise nil.

NOTE: Embedded links are not correctly handled currently. If an embedded link is detected, the whole term is returned as the link part (third argument), and the display part is nil. If you construct your own link from the link and display parts, you must check for this.

`parse_err_or_paramname` is an optional function of one or two arguments to display an error, or a string naming a parameter to display in the error message. If omitted, a function is generated based off of `term`. (The second argument to the function is the number of stack frames to ignore when calling error; if you declare your error function with only one argument, things will still work fine.) ]==] function export.parse_term_with_lang(data_or_term, parse_err_or_paramname) if type(data_or_term) == "string" then data_or_term = { term = data_or_term }		if type(parse_err_or_paramname) == "function" then data_or_term.parse_err = parse_err_or_paramname else data_or_term.paramname = parse_err_or_paramname end end local term = data_or_term.term local parse_err = data_or_term.parse_err or		data_or_term.paramname and export.make_parse_err(("%s=%s"):format(data_or_term.paramname, term)) or		export.make_parse_err(term) -- Parse off an initial language code (e.g. 'la:minūtia' or 'grc:σκατός'). First check for Wikipedia -- prefixes ('w:Abatemarco' or 'w:it:Colle Val d'Elsa' or 'lw:zh:邹衡') and Wikisource prefixes -- ('s:ro:Mr. Vucea' or 'ls:ko:이상적 부인'). Wikipedia/Wikisource language codes follow a similar -- format to Wiktionary language codes (see below). Here and below we don't parse if there's a space after the -- colon (happens e.g. if the user uses inside of 🇨🇴, grrr ...). local termlang, foreign_wiki, actual_term = term:match("^(l?[ws]):([a-z][a-z][a-z-]*):([^ ].*)$") if not termlang then termlang, actual_term = term:match("^([ws]):([^ ].*)$") end if termlang then local wiki_links = termlang:find("^l") local base_wiki_prefix = termlang:find("w$") and "w:" or "s:" local wiki_prefix = base_wiki_prefix .. (foreign_wiki and foreign_wiki .. ":" or "") local link, display = parse_bracketed_term(actual_term, parse_err) if link:find("%[%[") or display and display:find("%[%[") then -- FIXME, this should be handlable with the right parsing code parse_err("Cannot have embedded brackets following a Wikipedia (w:... or lw:...) link; expand the term to a fully bracketed term w:DISPLAY or similar") end local lang = wiki_links and require("Module:languages").getByCode(foreign_wiki, parse_err, "allow etym") or nil local prefixed_link = wiki_prefix .. link return ("%s"):format(prefixed_link, display or link), lang, prefixed_link, display end

-- Wiktionary language codes are in one of the following formats, where 'x' is a lowercase letter and 'X' an	-- uppercase letter: -- xx	-- xxx -- xxx-xxx -- xxx-xxx-xxx (esp. for protolanguages) -- xx-xxx (for etymology-only languages) -- xx-xxx-xxx (maybe? for etymology-only languages) -- xx-XX (for etymology-only languages, where XX is a country code, e.g. en-US) -- xxx-XX (for etymology-only languages, where XX is a country code) -- xx-xxx-XX (for etymology-only languages, where XX is a country code) -- xxx-xxx-XX (for etymology-only langauges, where XX is a country code, e.g. nan-hbl-PH) -- Things like xxx-x+ (e.g. cmn-pinyin, cmn-tongyong) -- VL., LL., etc.	-- -- We check the for nonstandard Latin etymology language codes separately, and otherwise make only the following -- assumptions: -- (1) There are one to three hyphen-separated components. -- (2) The last component can consist of two uppercase ASCII letters; otherwise, all components contain only --    lowercase ASCII letters. -- (3) Each component must have at least two letters. -- (4) The first component must have two or three letters. local function is_possible_lang_code(code) -- Special hack for Latin variants, which can have nonstandard etym codes, e.g. VL., LL. if code:find("^[A-Z]L%.$") then return true end return code:find("^([a-z][a-z][a-z]?)$") or			code:find("^[a-z][a-z][a-z]?%-[A-Z][A-Z]$") or			code:find("^[a-z][a-z][a-z]?%-[a-z][a-z]+$") or			code:find("^[a-z][a-z][a-z]?%-[a-z][a-z]+%-[A-Z][A-Z]$") or			code:find("^[a-z][a-z][a-z]?%-[a-z][a-z]+%-[a-z][a-z]+$") end

local function get_by_code(code, allow_bad) local lang if data_or_term.lang_cache then lang = data_or_term.lang_cache[code] end if lang == nil then lang = require("Module:languages").getByCode(code, not allow_bad and parse_err or nil, "allow etym",				data_or_term.allow_family) if data_or_term.lang_cache then data_or_term.lang_cache[code] = lang or false end end return lang or nil end

if data_or_term.allow_multiple then local termlang_spec termlang_spec, actual_term = term:match("^([a-zA-Z.,-]+):([^ ].*)$") if termlang_spec then termlang = rsplit(termlang_spec, ",") local all_possible_code = true for _, code in ipairs(termlang) do				if not is_possible_lang_code(code) then all_possible_code = false break end end if all_possible_code then local saw_nil = false for i, code in ipairs(termlang) do					termlang[i] = get_by_code(code, data_or_term.allow_bad) if not termlang[i] then saw_nil = true end end if saw_nil then termlang = nil else term = actual_term end else termlang = nil end end else termlang, actual_term = term:match("^([a-zA-Z.-]+):([^ ].*)$") if termlang then if is_possible_lang_code(termlang) then termlang = get_by_code(termlang, data_or_term.allow_bad) if termlang then term = actual_term end else termlang = nil end end end local link, display = parse_bracketed_term(term, parse_err) return term, termlang, link, display end

--[==[ Parse a term that may have inline modifiers attached (e.g. {rifiuti<q:plural-only>} or {rinfusa<t:bulk cargo><lit:resupplying><qq:more common in the plural >}). `generate_obj` are required):  error messages). return a corresponding parsed object (into which the inline modifiers will be rewritten). If declared with one argument, that will be the raw value to parse; if declared with two arguments, the second argument will be the `parse_err` function (see below). with any desired contextual text (e.g. the argument name and value that triggered the error). If omitted, a default function will be generated which displays the error along with the original value of `arg` (passed through  {escape_wikicode} above to ensure that Wikicode (such as links) is displayed literally). may be followed by inline modifiers, and the return value will be a list of parsed objects instead of a single object. Note that splitting on delimiters will not happen in certain protected sequences (by default  comma+whitespace; see below). The algorithm to split on delimiters is sensitive to inline modifier syntax and will not be confused by delimiters inside of inline modifiers, which do not trigger splitting (whether or not contained  within protected sequences). into which the list of per-term objects is stored (into the `terms` field) and into which any modifiers that are given the `overall` property (see below) will be stored. If given, this value will be returned as the value of  {parse_inline_modifiers}. If `outer_container` is not given, {parse_inline_modifiers} will return the list of  per-term objects directly, and no modifier may have an `overall` property. parsed object describing the element that comes after the delimiter. The delimiter is stored in a key whose name is controlled by `separator_key`, which defaults to "separator". See above. control the protected sequences that won't be split. By default, `escape_comma_whitespace` and `unescape_comma_whitespace` are used, so that comma+whitespace sequences won't be split. prior to further parsing. This is used, for example, in Module:tl-pronunciation to convert modifiers of the form to, so they can be processed as standard modifiers. It could similarly be used, for example, to handle boolean modifiers like in desc and convert them to a standard form. It runs just before parsing out the modifier prefix and value, and is passed an object containing fields `modtext` (the un-normalized modifier text, without surrounding angle  brackets) and `parse_err` (the passed-in or autogenerated function to signal an error during parsing; a function   of one argument, a message, which throws an error displaying that message). It should return a single value, the normalized value of `modtext`.
 * `arg` is the term to parse.
 * `props` is an object holding further properties controlling how to parse the term (only `param_mods` and
 * `paramname` is the name of the parameter where `arg` comes from, or nil if this isn't available (it is used only in
 * `param_mods` is a table describing the allowed inline modifiers (see below).
 * `generate_obj` is a function of one or two arguments that should parse the argument minus the inline modifiers and
 * `parse_err` is an optional function of one argument (an error message) and should display the error message, along
 * `splitchar` is a Lua pattern. If specified, `arg` can consist of multiple delimiter-separated terms, each of which
 * `outer_container`, if specified, is used when multiple delimiter-separated terms are possible, and is the object
 * `preserve_splitchar`, if specified, causes the actual delimiter matched by `splitchar` to be returned in the
 * `separator_key` controls the key into which the actual delimiter is written when `preserve_splitchar` is used.
 * `escape_fun` and `unescape_fun` are as in split_escaping and split_alternating_runs_escaping above and
 * `pre_normalize_modifiers`, if specified, is a function of one argument, which can be used to "normalize" modifiers

`param_mods` is a table describing allowed modifiers. The keys of the table are modifier prefixes and the values are tables describing how to parse and store the associated modifier values. Here is a typical example, for an item that takes the standard modifiers associated with `full_link` in Module:links, as well as left and right qualifiers and labels:

{ local param_mods = { alt = {}, t = { -- Module:links expects the gloss in "gloss". item_dest = "gloss", },	gloss = {}, tr = {}, ts = {}, g = { -- Module:links expects the genders in "g". `sublist = true` automatically splits on comma (optionally		-- with surrounding whitespace). item_dest = "genders", sublist = true, },	pos = {}, lit = {}, id = {}, sc = { -- Automatically parse as a script code and convert to a script object. type = "script", },	-- Qualifiers and labels q = { type = "qualifier", qq = { type = "qualifier", }	l = { type = "labels", },	ll = { type = "labels", }, } }

In the table values: the object from the string form given by the user into the form needed for further processing. Note that `type` makes use of additional properties that may be specified. Specifically, if {type = "language"}, the properties `family` and `method` are also examined, and if {type = "family"} or {type = "script"}, the property `method` is examined. is simply written into the parsed object under the appropriate key; but an error is generated if the key already has a value. (This means that multiple occurrences of a given modifier are allowed if `store` is given, but not otherwise.) `store` can be one of the following: is first converted to an empty list; key's existing value using {table.insert}; {"insert-flattened"} and {"insertIfNot-flattened"}, if there is no existing value for the key, the converted value is  just stored directly. This means that future appends will side-effect that value, so make sure that the return value of the conversion function for this key generates a fresh list each time.)   the message about the modifier in question, the angle-bracket spec that includes the modifier in it, the overall	value, and (if `paramname` was given) the parameter holding the overall value.   to an individual term in the argument, and must occur after the last item separated by `splitchar`, instead of being   allowed to occur after any of them. The modifier will be stored into the outer container object, which must exist   (i.e. `outer_container` must have been given).
 * `item_dest` specifies the destination key to store the object into (if not the same as the modifier key itself).
 * `type`, `set`, `sublist` and `convert` have the same meaning as in Module:parameters and are used for converting
 * `store` describes how to store the converted modifier value into the parsed object. If omitted, the converted value
 * {"insert"}: the converted value is appended to the key's value using {table.insert}; if the key has no value, it
 * {"insertIfNot"}: is similar but appends the value using {insertIfNot} in Module:table;
 * {"insert-flattened"}, the converted value is assumed to be a list and the objects are appended one-by-one into the
 * {"insertIfNot-flattened"} is similar but appends using {insertIfNot} in Module:table; (WARNING: When using
 * a function of one argument, an object with the following properties:
 * `dest`: the object to write the value into;
 * `key`: the field where the value should be written;
 * `converted`: the (converted) value to write;
 * `raw_val`: the raw, user-specified value (a string);
 * `parse_err`: a function of one argument (an error string), which signals an error, and includes extra context in
 * `overall` only applies if `splitchar` is given. In this case, the modifier applies to the entire argument rather than

The return value of {parse_inline_modifiers} depends on whether `splitchar` and `outer_container` have been given. If neither is given, the return value is the object returned by `generate_obj`. If `splitchar` but not `outer_container` is given, the return value is a list of per-term objects, each of which is generated by `generate_obj`. If both `splitchar` and `outer_container` are given, the return value is the value of `outer_container` and the per-term objects are stored into the `terms` field of this object. ]==] function export.parse_inline_modifiers(arg, props) local segments = export.parse_balanced_segment_run(arg, "<", ">")

local function verify_no_overall for mod, mod_props in pairs(props.param_mods) do			if mod_props.overall then error("Internal caller error: Can't specify `overall` for a modifier in `param_mods` unless `outer_container` property is given") end end end

if not props.splitchar then if props.outer_container then error("Internal caller error: Can't specify `outer_container` property unless `splitchar` is given") end verify_no_overall return export.parse_inline_modifiers_from_segments { group = segments, group_index = nil, separated_groups = nil, arg = arg, props = props }	else local terms = {} if props.outer_container then props.outer_container.terms = terms else verify_no_overall end local separated_groups = export.split_alternating_runs_escaping(segments, props.splitchar,			props.preserve_splitchar, props.escape_fun or export.escape_comma_whitespace,			props.unescape_fun or export.unescape_comma_whitespace) for j = 1, #separated_groups, (props.preserve_splitchar and 2 or 1) do			local parsed = export.parse_inline_modifiers_from_segments { group = separated_groups[j], group_index = j,				separated_groups = separated_groups, arg = arg, props = props }			if props.preserve_splitchar and j > 1 then parsed[props.separator_key or "separator"] = separated_groups[j - 1][1] end table.insert(terms, parsed) end if props.outer_container then return props.outer_container else return terms end end end

--[==[ Parse a single term that may have inline modifiers attached. This is a helper function of {parse_inline_modifiers} but is exported separately in case the caller needs to make their own call to {parse_balanced_segment_run} (as in Module:quote, which splits on several matched delimiters simultaneously). It takes only a single argument, `data`, which is an object with the following fields: Module:parse utilities), or one of the lists returned by calling {split_alternating_runs}. argument parsed by {parse_inline_modifiers}, or {nil} if this isn't applicable (i.e. multiple terms aren't allowed in the argument).
 * `group`: A list of segments as output by {parse_balanced_segment_run} (see the overall comment at the top of
 * `separated_groups`: The list of groups (each of which is of the form of `group`) describing all the terms in the
 * `group_index`: The index into `separated_groups` where `group` can be found, or {nil} if not applicable.
 * `arg`: The original user-specified argument being parsed; used only for error messages.
 * `props`: The `props` argument to {parse_inline_modifiers}.

The return value is the object created by `generate_obj`, with properties filled in describing the modifiers of the term in question. ]==] function export.parse_inline_modifiers_from_segments(data) local props = data.props local group = data.group local function get_valid_prefixes local valid_prefixes = {} for param_mod, _ in pairs(props.param_mods) do			table.insert(valid_prefixes, param_mod) end table.sort(valid_prefixes) return valid_prefixes end

local function get_arg_gloss if props.paramname then return ("%s=%s"):format(props.paramname, data.arg) else return data.arg end end

local parse_err = props.parse_err or export.make_parse_err(get_arg_gloss) local term_obj = props.generate_obj(group[1], parse_err) for k = 2, #group - 1, 2 do		if group[k + 1] ~= "" then parse_err("Extraneous text '" .. group[k + 1] .. "' after modifier") end local modtext = group[k]:match("^<(.*)>$") if not modtext then parse_err("Internal error: Modifier '" .. group[k] .. "' isn't surrounded by angle brackets") end if props.pre_normalize_modifiers then -- FIXME: For some use cases, we might have to pass more information. modtext = props.pre_normalize_modifiers { modtext = modtext, parse_err = parse_err }		end local prefix, val = modtext:match("^([a-zA-Z0-9+_-]+):(.*)$") if not prefix then local valid_prefixes = get_valid_prefixes for i, valid_prefix in ipairs(valid_prefixes) do valid_prefixes[i] = "'" .. valid_prefix .. ":'"			end parse_err("Modifier " .. group[k] .. " lacks a prefix, should begin with one of " ..				require("Module:table").serialCommaJoin(valid_prefixes, {dontTag = true})) end local prefix_parse_err = export.make_parse_err(("modifier prefix '%s' in %s in %s"):format(prefix, group[k], get_arg_gloss)) if props.param_mods[prefix] then local mod_props = props.param_mods[prefix] local key = mod_props.item_dest or prefix local dest if mod_props.overall then if not data.separated_groups then prefix_parse_err("Internal error: `data.separated_groups` not given when `overall` is seen") end if not props.outer_container then -- This should have been caught earlier during validation in parse_inline_modifiers. prefix_parse_err("Internal error: `props.outer_container` not given when `overall` is seen") end if data.group_index ~= #data.separated_groups then prefix_parse_err("Prefix should occur after the last comma-separated term") end dest = props.outer_container else dest = term_obj end

local converted = val if mod_props.type or mod_props.set or mod_props.sublist or mod_props.convert then -- WARNING: Here as an optimization we embed some knowledge of convert_val in Module:parameters, -- specifically that if none of `type`, `set`, `sublist` and `convert` are set, the conversion is an -- identity operation and can be skipped. (convert_val also makes use of the fields `method` and				-- `family`, but only if `type` is set to certain values such as "language", "family" or "script", and				-- makes use of the field `required`, but only if `set` is set.) If this becomes problematic, consider -- removing the optimization. converted = require(parameters_module).convert_val(converted, prefix_parse_err, mod_props) end local store = props.param_mods[prefix].store if not store then if dest[key] then prefix_parse_err("Prefix occurs twice") end dest[key] = converted elseif store == "insert" then if not dest[key] then dest[key] = {converted} else table.insert(dest[key], converted) end elseif store == "insertIfNot" then if not dest[key] then dest[key] = {converted} else require("Module:table").insertIfNot(dest[key], converted) end elseif store == "insert-flattened" then if not dest[key] then dest[key] = converted else for _, obj in ipairs(converted) do						table.insert(dest[key], obj) end end elseif store == "insertIfNot-flattened" then if not dest[key] then dest[key] = converted else for _, obj in ipairs(converted) do						require("Module:table").insertIfNot(dest[key], obj) end end elseif type(store) == "string" then prefix_parse_err(("Internal caller error: Unrecognized value '%s' for `store` property"):format(store)) elseif type(store) ~= "function" then prefix_parse_err(("Internal caller error: Unrecognized type for `store` property %s"):format( mw.dumpObject(store))) else store { dest = dest, key = key, converted = converted, raw = val, parse_err = prefix_parse_err }			end else local valid_prefixes = get_valid_prefixes for i, valid_prefix in ipairs(valid_prefixes) do valid_prefixes[i] = "'" .. valid_prefix .. "'"			end prefix_parse_err("Unrecognized prefix, should be one of " ..				require("Module:table").serialCommaJoin(valid_prefixes, {dontTag = true})) end end return term_obj end

return export