Module:string utilities
Documentation for this module may be created at Module:string utilities/doc
local mw = mw
local string = string
local table = table
local ustring = mw.ustring
local byte = string.byte
local char = string.char
local concat = table.concat
local find = string.find
local format = string.format
local gmatch = string.gmatch
local gsub = string.gsub
local len = string.len
local load_data = mw.loadData
local lower = string.lower
local match = string.match
local next = next
local reverse = string.reverse
local select = select
local sort = table.sort
local sub = string.sub
local tonumber = tonumber
local tostring = tostring
local type = type
local ucodepoint = ustring.codepoint
local ufind = ustring.find
local ugcodepoint = ustring.gcodepoint
local ugmatch = ustring.gmatch
local ugsub = ustring.gsub
local ulower = ustring.lower
local umatch = ustring.match
local unpack = unpack
local upper = string.upper
local usub = ustring.sub
local uupper = ustring.upper
-- Defined below.
local charset_escape
local codepoint
local explode_utf8
local format_fun
local get_indefinite_article
local pattern_escape
local pattern_simplifier
local php_trim
local replacement_escape
local u
local ulen
local module_name = "string_utilities"
local export = {}
--[==[Explodes a string into an array of UTF-8 characters. '''Warning''': this function has no safety checks for non-UTF-8 byte sequences, to optimize speed and memory use. Inputs containing them therefore result in undefined behaviour.]==]
function export.explode_utf8(str)
local text, i = {}, 0
for ch in gmatch(str, ".[\128-\191]*") do
i = i + 1
text[i] = ch
end
return text
end
explode_utf8 = export.explode_utf8
--[==[Escapes the magic characters used in [[mw:Extension:Scribunto/Lua reference manual#Patterns|patterns]] (Lua's version of regular expressions): <code>$%()*+-.?[]^</code>. For example, {{code|lua|"^$()%.[]*+-?"}} becomes {{code|lua|"%^%$%(%)%%%.%[%]%*%+%-%?"}}. This is necessary when constructing a pattern involving arbitrary text (e.g. from user input).]==]
function export.pattern_escape(str)
return (gsub(str, "[$%%()*+%-.?[%]^]", "%%%0"))
end
pattern_escape = export.pattern_escape
--[==[Escapes only the magic characters used in [[mw:Extension:Scribunto/Lua reference manual#Patterns|pattern]] character sets: <code>%-]^</code>.]==]
function export.charset_escape(str)
return (gsub(str, "[%%%-%]^]", "%%%0"))
end
charset_escape = export.charset_escape
--[==[Escapes only <code>%</code>, which is the only magic character used in replacement [[mw:Extension:Scribunto/Lua reference manual#Patterns|patterns]] with string.gsub and mw.ustring.gsub.]==]
function export.replacement_escape(str)
return (gsub(str, "%%", "%%%%"))
end
replacement_escape = export.replacement_escape
do
local function check_sets_equal(set1, set2)
local k2
for k1, v1 in next, set1 do
local v2 = set2[k1]
if v1 ~= v2 and (v2 == nil or not check_sets_equal(v1, v2)) then
return false
end
k2 = next(set2, k2)
end
return next(set2, k2) == nil
end
local function check_sets(bytes)
local key, set1, set = next(bytes)
if set1 == true then
return true
elseif not check_sets(set1) then
return false
end
while true do
key, set = next(bytes, key)
if not key then
return true
elseif not check_sets_equal(set, set1) then
return false
end
end
end
local function make_charset(range)
if #range == 1 then
return char(range[1])
end
sort(range)
local compressed, n, start = {}, 0, range[1]
for i = 1, #range do
local this, nxt = range[i], range[i + 1]
if nxt ~= this + 1 then
n = n + 1
compressed[n] = this == start and char(this) or
char(start) .. "-" .. char(this)
start = nxt
end
end
return "[" .. concat(compressed) .. "]"
end
local function parse_1_byte_charset(pattern, pos)
while true do
local ch, nxt_pos
pos, ch, nxt_pos = match(pattern, "()([%%%]\194-\244][\128-\191]*)()", pos)
if not ch then
return false
elseif ch == "%" then
if match(pattern, "^[acdlpsuwxACDLPSUWXZ\128-\255]", nxt_pos) then
return false
end
pos = pos + 2
elseif ch == "]" then
pos = nxt_pos
return pos
else
return false
end
end
end
--[==[Parses `pattern`, a ustring library pattern, and attempts to convert it into a string library pattern. If conversion isn't possible, returns false.]==]
pattern_simplifier = require("Module:fun").memoize(function(pattern)
if type(pattern) == "number" then
return tostring(pattern)
end
local pos, captures, start, n, output = 1, 0, 1, 0
while true do
local ch, nxt_pos
pos, ch, nxt_pos = match(pattern, "()([%%(.[\194-\244][\128-\191]*)()", pos)
if not ch then
break
end
local nxt = sub(pattern, nxt_pos, nxt_pos)
if ch == "%" then
if nxt == "b" then
if not match(pattern, "^()[^\128-\255][^\128-\255]", pos + 2) then
return false
end
pos = pos + 4
elseif nxt == "f" then
pos = pos + 2
if not match(pattern, "^()%[[^^]", pos) then
return false
end
-- Only possible to convert a %f charset which is all
-- ASCII, so use parse_1_byte_charset.
pos = parse_1_byte_charset(pattern, pos)
if not pos then
return false
end
elseif nxt == "Z" then
pos = pos + 2
nxt = sub(pattern, pos, pos)
if nxt == "*" or nxt == "+" or nxt == "-" then
pos = pos + 1
else
output = output or {}
n = n + 1
if nxt == "?" then
output[n] = sub(pattern, start, pos - 3) .. "[\1-\127\194-\244]?[\128-\191]*"
pos = pos + 1
else
output[n] = sub(pattern, start, pos - 3) .. "[\1-\127\194-\244][\128-\191]*"
end
start = pos
end
elseif find("acdlpsuwxACDLPSUWX", nxt, 1, true) then
return false
-- Skip the next character if it's ASCII. Otherwise, we will
-- still need to do length checks.
else
pos = pos + (byte(nxt) < 128 and 2 or 1)
end
elseif ch == "(" then
if nxt == ")" or captures == 32 then
return false
end
captures = captures + 1
pos = pos + 1
elseif ch == "." then
if nxt == "*" or nxt == "+" or nxt == "-" then
pos = pos + 2
else
output = output or {}
n = n + 1
if nxt == "?" then
output[n] = sub(pattern, start, pos - 1) .. "[^\128-\191]?[\128-\191]*"
pos = pos + 2
else
output[n] = sub(pattern, start, pos - 1) .. "[^\128-\191][\128-\191]*"
pos = pos + 1
end
start = pos
end
elseif ch == "[" then
-- Fail negative charsets. TODO: 1-byte charsets should be safe.
if nxt == "^" then
return false
-- If the first character is "%", ch_len is determined by the
-- next one instead.
elseif nxt == "%" then
nxt_pos = nxt_pos + 1
nxt = sub(pattern, nxt_pos, nxt_pos)
end
local ch_len = #match(pattern, "^.[\128-\191]*", nxt_pos)
if ch_len == 1 then -- Single-byte charset.
pos = parse_1_byte_charset(pattern, pos + 1)
if not pos then
return false
end
else -- Multibyte charset.
local charset_pos, bytes = pos
pos = pos + 1
while true do -- TODO: non-ASCII charset ranges.
pos, ch, nxt_pos = match(pattern, "()([^\128-\191][\128-\191]*)()", pos)
if not ch then
return false
-- If escaped, get the next character. No need to
-- distinguish magic characters or character classes,
-- as they'll all fail for having the wrong length
-- anyway.
elseif ch == "%" then
pos, ch, nxt_pos = match(pattern, "()([^\128-\191][\128-\191]*)()", pos)
elseif ch == "]" then
pos = nxt_pos
break
end
if ch_len ~= #ch then
return false
end
bytes = bytes or {}
local bytes = bytes
for i = 1, ch_len - 1 do
local b = byte(ch, i, i)
bytes[b] = bytes[b] or {}
bytes = bytes[b]
end
bytes[byte(ch, -1)] = true
pos = nxt_pos
end
if not pos then
return false
end
local nxt = sub(pattern, pos, pos)
if (
(nxt == "?" or nxt == "*" or nxt == "-") or
(nxt == "+" and ch_len > 2) or
not check_sets(bytes)
) then
return false
end
local ranges, b, key, next_byte = {}, 0
repeat
key, next_byte = next(bytes)
local range, n = {key}, 1
-- Loop starts on the second iteration.
for key in next, bytes, key do
n = n + 1
range[n] = key
end
b = b + 1
ranges[b] = range
bytes = next_byte
until next_byte == true
if nxt == "+" then
local range1, range2 = ranges[1], ranges[2]
ranges[1] = make_charset(range1)
ranges[3] = make_charset(range2)
local n = #range2
for i = 1, #range1 do
n = n + 1
range2[n] = range1[i]
end
ranges[2] = make_charset(range2) .. "*"
pos = pos + 1
else
for i = 1, #ranges do
ranges[i] = make_charset(ranges[i])
end
end
output = output or {}
n = n + 1
output[n] = sub(pattern, start, charset_pos - 1) .. concat(ranges)
start = pos
end
elseif nxt == "+" then
if #ch ~= 2 then
return false
end
output = output or {}
n = n + 1
output[n] = sub(pattern, start, pos) .. "[" .. ch .. "]*" .. sub(ch, 2, 2)
pos = nxt_pos + 1
start = pos
elseif nxt == "?" or nxt == "*" or nxt == "-" then
return false
else
pos = nxt_pos
end
end
if start == 1 then
return pattern
end
return concat(output) .. sub(pattern, start)
end, true)
export.pattern_simplifier = pattern_simplifier -- For testing.
end
function export.len(str)
return type(str) == "number" and len(str) or
#str - #gsub(str, "[^\128-\191]+", "")
end
ulen = export.len
function export.sub(str, i, j)
str, i = type(str) == "number" and tostring(str) or str, i or 1
if i < 0 or j and j < 0 then
return usub(str, i, j)
elseif j and i > j or i > #str then
return ""
end
local n, new_i = 0
for loc1, loc2 in gmatch(str, "()[^\128-\191]+()[\128-\191]*") do
n = n + loc2 - loc1
if not new_i and n >= i then
new_i = loc2 - (n - i) - 1
if not j then
return sub(str, new_i)
end
end
if j and n > j then
return sub(str, new_i, loc2 - (n - j) - 1)
end
end
return new_i and sub(str, new_i) or ""
end
do
local function _find(str, loc1, loc2, ...)
if loc1 and not match(str, "^()[^\128-\255]*$") then
-- Use raw values of loc1 and loc2 to get loc1 and the length of the match.
loc1, loc2 = ulen(sub(str, 1, loc1)), ulen(sub(str, loc1, loc2))
-- Offset length with loc1 to get loc2.
loc2 = loc1 + loc2 - 1
end
return loc1, loc2, ...
end
--[==[A version of find which uses string.find when possible, but otherwise uses mw.ustring.find.]==]
function export.find(str, pattern, init, plain)
init = init or 1
if init ~= 1 and not match(str, "^()[^\128-\255]*$") then
return ufind(str, pattern, init, plain)
elseif plain then
return _find(str, find(str, pattern, init, true))
end
local simple = pattern_simplifier(pattern)
if simple then
return _find(str, find(str, simple, init))
end
return ufind(str, pattern, init)
end
end
--[==[A version of match which uses string.match when possible, but otherwise uses mw.ustring.match.]==]
function export.match(str, pattern, init)
init = init or 1
if init ~= 1 and not match(str, "^()[^\128-\255]*$") then
return umatch(str, pattern, init)
end
local simple = pattern_simplifier(pattern)
if simple then
return match(str, simple, init)
end
return umatch(str, pattern, init)
end
--[==[A version of gmatch which uses string.gmatch when possible, but otherwise uses mw.ustring.gmatch.]==]
function export.gmatch(str, pattern)
local simple = pattern_simplifier(pattern)
if simple then
return gmatch(str, simple)
end
return ugmatch(str, pattern)
end
--[==[A version of gsub which uses string.gsub when possible, but otherwise uses mw.ustring.gsub.]==]
function export.gsub(str, pattern, repl, n)
local simple = pattern_simplifier(pattern)
if simple then
return gsub(str, simple, repl, n)
end
return ugsub(str, pattern, repl, n)
end
--[==[Like gsub, but pattern-matching facilities are turned off, so `pattern` and `repl` (if a string) are treated as literal.]==]
function export.plain_gsub(str, pattern, repl, n)
return gsub(str, pattern_escape(pattern), type(repl) == "string" and replacement_escape(repl) or repl, n)
end
--[==[Reverses a UTF-8 string; equivalent to string.reverse.]==]
function export.reverse(str)
return reverse(gsub(str, "[\194-\244][\128-\191]*", reverse))
end
do
local function err(cp)
error("Codepoint " .. cp .. " is out of range: codepoints must be between 0x0 and 0x10FFFF.", 2)
end
local function utf8_char(cp)
cp = tonumber(cp)
if cp < 0 then
err("-0x" .. format("%X", -cp + 1))
elseif cp < 0x80 then
return char(cp)
elseif cp < 0x800 then
return char(
0xC0 + cp / 0x40,
0x80 + cp % 0x40
)
elseif cp < 0x10000 then
if cp >= 0xD800 and cp < 0xE000 then
return "?" -- mw.ustring.char returns "?" for surrogates.
end
return char(
0xE0 + cp / 0x1000,
0x80 + cp / 0x40 % 0x40,
0x80 + cp % 0x40
)
elseif cp < 0x110000 then
return char(
0xF0 + cp / 0x40000,
0x80 + cp / 0x1000 % 0x40,
0x80 + cp / 0x40 % 0x40,
0x80 + cp % 0x40
)
end
err("0x" .. format("%X", cp))
end
function export.char(cp, ...)
if ... == nil then
return utf8_char(cp)
end
local ret = {cp, ...}
for i = 1, select("#", cp, ...) do
ret[i] = utf8_char(ret[i])
end
return concat(ret)
end
u = export.char
end
do
local function get_codepoint(b1, b2, b3, b4)
if b1 < 128 then
return b1, 1
elseif b1 < 224 then
return 0x40 * b1 + b2 - 0x3080, 2
elseif b1 < 240 then
return 0x1000 * b1 + 0x40 * b2 + b3 - 0xE2080, 3
end
return 0x40000 * b1 + 0x1000 * b2 + 0x40 * b3 + b4 - 0x3C82080, 4
end
function export.codepoint(str, i, j)
if type(str) == "number" then
return byte(str, i, j)
end
i, j = i or 1, j == -1 and #str or i or 1
if i == 1 and j == 1 then
return (get_codepoint(byte(str, 1, 4)))
elseif i < 0 or j < 0 then
return ucodepoint(str, i, j) -- FIXME
end
local n, nb, ret, nr = 0, 1, {}, 0
while n < j do
n = n + 1
if n < i then
local b = byte(str, nb)
nb = nb + (b < 128 and 1 or b < 224 and 2 or b < 240 and 3 or 4)
else
local b1, b2, b3, b4 = byte(str, nb, nb + 3)
if not b1 then
break
end
nr = nr + 1
local add
ret[nr], add = get_codepoint(b1, b2, b3, b4)
nb = nb + add
end
end
return unpack(ret)
end
codepoint = export.codepoint
function export.gcodepoint(str, i, j)
i, j = i or 1, j ~= -1 and j or nil
if i < 0 or j and j < 0 then
return ugcodepoint(str, i, j) -- FIXME
end
local n, nb = 1, 1
while n < i do
local b = byte(str, nb)
if not b then
break
end
nb = nb + (b < 128 and 1 or b < 224 and 2 or b < 240 and 3 or 4)
n = n + 1
end
return function()
if j and n > j then
return nil
end
n = n + 1
local b1, b2, b3, b4 = byte(str, nb, nb + 3)
if not b1 then
return nil
end
local ret, add = get_codepoint(b1, b2, b3, b4)
nb = nb + add
return ret
end
end
end
--[==[A version of lower which uses string.lower when possible, but otherwise uses mw.ustring.lower.]==]
function export.lower(str)
return (match(str, "^()[^\128-\255]*$") and lower or ulower)(str)
end
--[==[A version of upper which uses string.upper when possible, but otherwise uses mw.ustring.upper.]==]
function export.upper(str)
return (match(str, "^()[^\128-\255]*$") and upper or uupper)(str)
end
do
local function add_captures(text, n, ...)
-- Insert any captures from the splitting pattern.
local offset, capture = n - 1, ...
while capture do
n = n + 1
text[n] = capture
capture = select(n - offset, ...)
end
return n
end
local function iterate(str, str_len, text, n, start, _sub, loc1, loc2, ...)
if not (loc1 and start <= str_len) then
-- If no match, or there is but we're past the end of the string
-- (which happens when the match is the empty string), then add
-- the final chunk and return.
n = n + 1
text[n] = _sub(str, start)
return
elseif loc2 < loc1 then
-- Special case: If we match the empty string, then include the
-- next character; this avoids an infinite loop, and makes
-- splitting by an empty string work the way mw.text.split() does
-- (including non-adjacent empty string matches with %f). If we
-- reach the end of the string this way, return immediately, so we
-- don't get a final empty string. If using the string library, we
-- need to make sure we advance by one UTF-8 character.
if _sub == sub then
loc1 = loc1 + #match(str, "^[\128-\191]*", loc1 + 1)
end
n = n + 1
text[n] = _sub(str, start, loc1)
start = loc1 + 1
if start > str_len then
return ... and add_captures(text, n, ...) or n
end
else
-- Add chunk up to the current match.
n = n + 1
text[n] = _sub(str, start, loc1 - 1)
start = loc2 + 1
end
return (... and add_captures(text, n, ...) or n), start
end
local function _split(str, pattern, str_len, _sub, _find, plain)
local text, n, start = {}, 0, 1
repeat
n, start = iterate(str, str_len, text, n, start, _sub, _find(str, pattern, start, plain))
until not start
return text
end
--[==[Reimplementation of mw.text.split() that includes any capturing groups in the splitting pattern. This works like Python's re.split() function, except that it has Lua's behavior when the split pattern is empty (i.e. advancing by one character at a time; Python returns the whole remainder of the string). When possible, it will use the string library, but otherwise uses the ustring library. There are two optional parameters: `str_lib` forces use of the string library, while `plain` turns any pattern matching facilities off, treating `pattern` as literal.]==]
function export.split(str, pattern, str_lib, plain)
if str_lib or plain then
return _split(str, pattern, #str, sub, find, plain)
end
local simple = pattern_simplifier(pattern)
if simple then
return _split(str, simple, #str, sub, find)
end
return _split(str, pattern, ulen(str), usub, ufind)
end
export.capturing_split = export.split -- To be removed.
end
do
-- TODO: merge this with export.split. Not clear how to do this while
-- maintaining the same level of performance, as gsplit is slower.
local function _split(str, pattern, str_len, _sub, _find, plain)
local start, final = 1
local function iter(loc1, loc2, ...)
-- If no match, return the final chunk.
if not loc1 then
final = true
return _sub(str, start)
end
-- Special case: If we match the empty string, then eat the
-- next character; this avoids an infinite loop, and makes
-- splitting by the empty string work the way mw.text.gsplit() does
-- (including non-adjacent empty string matches with %f). If we
-- reach the end of the string this way, set `final` to true, so we
-- don't get stuck matching the empty string at the end.
local chunk
if loc2 < loc1 then
-- If using the string library, we need to make sure we advance
-- by one UTF-8 character.
if _sub == sub then
loc1 = loc1 + #match(str, "^[\128-\191]*", loc1 + 1)
end
chunk = _sub(str, start, loc1)
if loc1 >= str_len then
final = true
else
start = loc1 + 1
end
-- Eat chunk up to the current match.
else
chunk = _sub(str, start, loc1 - 1)
start = loc2 + 1
end
return chunk, ...
end
return function()
if not final then
return iter(_find(str, pattern, start, plain))
end
return nil
end
end
function export.gsplit(str, pattern, str_lib, plain)
if str_lib or plain then
return _split(str, pattern, #str, sub, find, plain)
end
local simple = pattern_simplifier(pattern)
if simple then
return _split(str, simple, #str, sub, find)
end
return _split(str, pattern, ulen(str), usub, ufind)
end
end
function export.trim(str, charset)
if not charset then
return match(str, "^()%s*$") and "" or match(str, "^%s*(.*%S)")
elseif match(charset, "^()[^\128-\255]*$") then
return match(str, "^()[" .. charset .. "]*$") and "" or match(str, "^[" .. charset .. "]*(.*[^" .. charset .. "])")
end
return umatch(str, "^[" .. charset .. "]*(.-)[" .. charset .. "]*$")
end
do
local entities
local function decode_numeric_entity(code, pattern, base)
local cp = match(code, pattern) and tonumber(code, base)
return cp and cp < 0x110000 and u(cp) or nil
end
local function decode_entity(hash, x, code)
if hash == "#" then
return x == "" and decode_numeric_entity(code, "^%d+$") or
decode_numeric_entity(code, "^%x+$", 16)
end
entities = entities or load_data("Module:data/entities")
return entities[x .. code]
end
-- Non-ASCII characters aren't valid in proper HTML named entities, but MediaWiki uses them in some custom aliases which have also been included in [[Module:data/entities]].
function export.decode_entities(str)
return find(str, "&", 1, true) and
gsub(str, "&(#?)([xX]?)([%w\128-\255]+);", decode_entity) or str
end
end
do
local html_entities
local function encode_entity(ch)
local entity = html_entities[ch]
if entity then
return entity
end
entity = "&#" .. codepoint(ch) .. ";"
html_entities[ch] = entity
return entity
end
function export.encode_entities(str, charset, str_lib, plain)
-- Memoized HTML entities (taken from mw.text.lua).
html_entities = html_entities or {
["\""] = """,
["&"] = "&",
["'"] = "'",
["<"] = "<",
[">"] = ">",
["\194\160"] = " ",
}
if not charset then
return (gsub(str, "[\"&'<>\194]\160?", html_entities))
elseif plain then
return (gsub(str, "[" .. charset_escape(charset) .. "]", encode_entity))
elseif str_lib then
if not match(charset, "^()[^\128-\255]*$") then
error("Cannot use the string library with a character set that contains a character with a codepoint above U+007F.")
end
return (gsub(str, "[" .. charset .. "]", encode_entity))
end
local pattern = charset and "[" .. charset .. "]"
local simple = pattern_simplifier(pattern)
if simple then
return (gsub(str, simple, encode_entity))
end
return (ugsub(str, pattern, encode_entity))
end
end
do
local function decode_path(code)
return char(tonumber(code, 16))
end
local function decode(lead, trail)
if lead == "+" or lead == "_" then
return " " .. trail
elseif #trail == 2 then
return decode_path(trail)
end
return lead .. trail
end
function export.decode_uri(str, enctype)
enctype = enctype and upper(enctype) or "QUERY"
if enctype == "PATH" then
return find(str, "%", 1, true) and
gsub(str, "%%(%x%x)", decode_path) or str
elseif enctype == "QUERY" then
return (find(str, "%", 1, true) or find(str, "+", 1, true)) and
gsub(str, "([%%%+])(%x?%x?)", decode) or str
elseif enctype == "WIKI" then
return (find(str, "%", 1, true) or find(str, "_", 1, true)) and
gsub(str, "([%%_])(%x?%x?)", decode) or str
end
error("bad argument #2 to \"decode_uri\" (expected QUERY, PATH, or WIKI)", 2)
end
end
do
local function _remove_comments(str, pre)
local head = find(str, "<!--", 1, true)
if not head then
return str
end
local ret, n = {sub(str, 1, head - 1)}, 1
while true do
local loc = find(str, "-->", head + 4, true)
if not loc then
return pre and concat(ret) or
concat(ret) .. sub(str, head)
end
head = loc + 3
loc = find(str, "<!--", head, true)
if not loc then
return concat(ret) .. sub(str, head)
end
n = n + 1
ret[n] = sub(str, head, loc - 1)
head = loc
end
end
--[==[Removes any HTML comments from the input text. `stage` can be one of three options:
* {{lua|"PRE"}} (default) applies the method used by MediaWiki's preprocessor: all {{code||<nowiki><!-- ... --></nowiki>}} pairs are removed, as well as any text after an unclosed {{code||<nowiki><!--</nowiki>}}. This is generally suitable when parsing raw template or [[mw:Parser extension tags|parser extension tag]] code. (Note, however, that the actual method used by the preprocessor is considerably more complex and differs under certain conditions (e.g. comments inside nowiki tags); if full accuracy is absolutely necessary, use [[Module:template parser]] instead).
* {{lua|"POST"}} applies the method used to generate the final page output once all templates have been expanded: it loops over the text, removing any {{code||<nowiki><!-- ... --></nowiki>}} pairs until no more are found (e.g. {{code||<nowiki><!-<!-- ... -->- ... --></nowiki>}} would be fully removed), but any unclosed {{code||<nowiki><!--</nowiki>}} is ignored. This is suitable for handling links embedded in template inputs, where the {{lua|"PRE"}} method will have already been applied by the native parser.
* {{lua|"BOTH"}} applies {{lua|"PRE"}} then {{lua|"POST"}}.]==]
function export.remove_comments(str, stage)
if not stage or stage == "PRE" then
return _remove_comments(str, true)
end
local processed = stage == "POST" and _remove_comments(str) or
stage == "BOTH" and _remove_comments(str, true) or
error("bad argument #2 to \"remove_comments\" (expected PRE, POST, or BOTH)", 2)
while processed ~= str do
str = processed
processed = _remove_comments(str)
end
return str
end
end
--[==[Lua equivalent of PHP's {{code|php|trim($string)}}, which trims {{code|lua|"\0"}}, {{code|lua|"\t"}}, {{code|lua|"\n"}}, {{code|lua|"\v"}}, {{code|lua|"\r"}} and {{code|lua|" "}}. This is useful when dealing with template parameters, since the native parser trims them like this.]==]
function export.php_trim(str)
return match(str, "%f[^%z\t\n\v\r ].*%f[%z\t\n\v\r ]") or ""
end
php_trim = export.php_trim
--[==[Takes a parameter name as an input, and returns the Scribunto-normalized form (i.e. the key that that parameter would have in a {{code|lua|frame.args}} table). For example, {{code|lua|"1"}} is normalized to {{code|lua|1}} (a number), and {{code|lua|" foo "}} is normalized to {{code|lua|"foo"}}. If the input is not a string, it is returned unchanged.
After being trimmed with {{code|lua|export.php_trim}}, strings are converted to numbers if:
# They are integers, with no decimals (2.0) or leading zeroes (02).
# They are ≤ 2{{sup|53}} and ≥ -2{{sup|53}}.
# For positive values, they do not have a leading {{code|lua|+}} sign.]==]
function export.scribunto_param_key(key)
if type(key) ~= "string" then
return key
end
key = php_trim(key)
if match(key, "^-?[1-9]%d*$") then
local num = tonumber(key)
-- Lua integers are only accurate to 2^53 - 1, so we have to specifically check for 2^53 and -2^53, since 2^53 == 2^53 + 1 evaluates to true.
return (
num <= 9007199254740991 and num >= -9007199254740991 or
key == "9007199254740992" or
key == "-9007199254740992"
) and num or key
elseif key == "0" then
return 0
end
return key
end
do
local byte_escapes
local function escape_byte(b)
return byte_escapes[b] or format("\\%03d", byte(b))
end
function export.escape_bytes(str)
byte_escapes = byte_escapes or load_data("Module:string utilities/data").byte_escapes
return (gsub(str, ".", escape_byte))
end
end
function export.format_fun(str, fun)
return (gsub(str, "{(\\?)((\\?)[^{}]*)}", function(p1, name, p2)
if #p1 + #p2 == 1 then
return name == "op" and "{" or
name == "cl" and "}" or
error(module_name .. ".format: unrecognized escape sequence '{\\" .. name .. "}'")
elseif fun(name) and type(fun(name)) ~= "string" then
error(module_name .. ".format: \"" .. name .. "\" is a " .. type(fun(name)) .. ", not a string")
end
return fun(name) or error(module_name .. ".format: \"" .. name .. "\" not found in table")
end))
end
format_fun = export.format_fun
--[==[This function, unlike {{code|lua|string.format}} and {{code|lua|mw.ustring.format}}, takes just two parameters—a format string and a table—and replaces all instances of {{code|lua|{param_name}}} in the format string with the table's entry for {{code|lua|param_name}}. The opening and closing brace characters can be escaped with <code>{\op}</code> and <code>{\cl}</code>, respectively. A table entry beginning with a slash can be escaped by doubling the initial slash.
====Examples====
* {{code|lua|2=string_utilities.format("{foo} fish, {bar} fish, {baz} fish, {quux} fish", {["foo"]="one", ["bar"]="two", ["baz"]="red", ["quux"]="blue"})}}
*: produces: {{code|lua|"one fish, two fish, red fish, blue fish"}}
* {{code|lua|2=string_utilities.format("The set {\\op}1, 2, 3{\\cl} contains {\\\\hello} elements.", {["\\hello"]="three"})}}
*: produces: {{code|lua|"The set {1, 2, 3} contains three elements."}}
*:* Note that the single and double backslashes should be entered as double and quadruple backslashes when quoted in a literal string.]==]
function export.format(str, tbl)
return format_fun(str, function(key)
return tbl[key]
end)
end
do
local function do_uclcfirst(str, case_func)
-- Actual function to re-case of the first letter.
local first_letter = case_func(match(str, "^.[\128-\191]*") or "")
return first_letter .. sub(str, #first_letter + 1)
end
local function uclcfirst(str, case_func)
-- If there's a link at the beginning, re-case the first letter of the
-- link text. This pattern matches both piped and unpiped links.
-- If the link is not piped, the second capture (linktext) will be empty.
local link, linktext, remainder = match(str, "^%[%[([^|%]]+)%|?(.-)%]%](.*)$")
if link then
return "[[" .. link .. "|" .. do_uclcfirst(linktext ~= "" and linktext or link, case_func) .. "]]" .. remainder
end
return do_uclcfirst(str, case_func)
end
function export.ucfirst(str)
return uclcfirst(str, uupper)
end
function export.lcfirst(str)
return uclcfirst(str, ulower)
end
local function capitalize(w)
return uclcfirst(w, uupper)
end
--[==[Capitalize each word of a string. WARNING: May be broken in the presence of multiword links.]==]
function export.capitalize(str)
if type(str) == "table" then
-- allow calling from a template
str = str.args[1]
end
-- Capitalize multi-word that is separated by spaces
-- by uppercasing the first letter of each part.
-- I assume nobody will input all CAP text.
return (ugsub(str, "%S+", capitalize))
end
end
do
local function word_ends_in_consonant_plus_y(str)
-- FIXME, a subrule of rule #1 above says the -ies ending doesn't
-- apply to proper nouns, hence "the Gettys", "the public Ivys".
-- We should maybe consider applying this rule here; but it may not
-- be important as this function is almost always called on common nouns
-- (e.g. parts of speech, place types).
return find(str, "[^aeiouAEIOU ]y$")
end
local function word_takes_es_plural(str)
return find(str, "[sxz]$") or find(str, "[cs]h$")
end
local function do_pluralize(str)
if word_ends_in_consonant_plus_y(str) then
-- avoid returning multiple values
return (gsub(str, "y$", "ies"))
elseif word_takes_es_plural(str) then
return str .. "es"
end
return str .. "s"
end
--[==[
Pluralize a word in a smart fashion, according to normal English rules.
# If word ends in consonant + -y, replace the -y with -ies.
# If the word ends in -s, -x, -z, -sh, -ch, add -es.
# Otherwise, add -s.
This handles links correctly:
# If a piped link, change the second part appropriately.
# If a non-piped link and rule #1 above applies, convert to a piped link with the second part containing the plural.
# If a non-piped link and rules #2 or #3 above apply, add the plural outside the link.
]==]
function export.pluralize(str)
if type(str) == "table" then
-- allow calling from a template
str = str.args[1]
end
-- Check for a link. This pattern matches both piped and unpiped links.
-- If the link is not piped, the second capture (linktext) will be empty.
local beginning, link, linktext = match(str, "^(.*)%[%[([^|%]]+)%|?(.-)%]%]$")
if not link then
return do_pluralize(str)
elseif linktext ~= "" then
return beginning .. "[[" .. link .. "|" .. do_pluralize(linktext) .. "]]"
elseif word_ends_in_consonant_plus_y(link) then
return beginning .. "[[" .. link .. "|" .. gsub(link, "y$", "ies") .. "]]"
end
return beginning .. "[[" .. link .. "]]" .. (word_takes_es_plural(link) and "es" or "s")
end
end
do
local function do_singularize(str)
local sing = match(str, "^(.-)ies$")
if sing then
return sing .. "y"
end
-- Handle cases like "[[parish]]es"
return match(str, "^(.-[sc]h%]*)es$") or
-- Handle cases like "[[box]]es"
match(str, "^(.-x%]*)es$") or
-- Handle regular plurals
match(str, "^(.-)s$") or
-- Otherwise, return input
str
end
local function collapse_link(link, linktext)
if link == linktext then
return "[[" .. link .. "]]"
end
return "[[" .. link .. "|" .. linktext .. "]]"
end
--[==[
Singularize a word in a smart fashion, according to normal English rules. Works analogously to {pluralize()}.
'''NOTE''': This doesn't always work as well as {pluralize()}. Beware. It will mishandle cases like "passes" -> "passe", "eyries" -> "eyry".
# If word ends in -ies, replace -ies with -y.
# If the word ends in -xes, -shes, -ches, remove -es. [Does not affect -ses, cf. "houses", "impasses".]
# Otherwise, remove -s.
This handles links correctly:
# If a piped link, change the second part appropriately. Collapse the link to a simple link if both parts end up the same.
# If a non-piped link, singularize the link.
# A link like "[[parish]]es" will be handled correctly because the code that checks for -shes etc. allows ] characters between the
'sh' etc. and final -es.
]==]
function export.singularize(str)
if type(str) == "table" then
-- allow calling from a template
str = str.args[1]
end
-- Check for a link. This pattern matches both piped and unpiped links.
-- If the link is not piped, the second capture (linktext) will be empty.
local beginning, link, linktext = match(str, "^(.*)%[%[([^|%]]+)%|?(.-)%]%]$")
if not link then
return do_singularize(str)
elseif linktext ~= "" then
return beginning .. collapse_link(link, do_singularize(linktext))
end
return beginning .. "[[" .. do_singularize(link) .. "]]"
end
end
--[==[
Return the appropriate indefinite article to prefix to `str`. Correctly handles links and capitalized text.
Does not correctly handle words like [[union]], [[uniform]] and [[university]] that take "a" despite beginning with
a 'u'. The returned article will have its first letter capitalized if `ucfirst` is specified, otherwise lowercase.
]==]
function export.get_indefinite_article(str, ucfirst)
str = str or ""
local is_vowel = false
-- If there's a link at the beginning, examine the first letter of the
-- link text. This pattern matches both piped and unpiped links.
-- If the link is not piped, the second capture (linktext) will be empty.
local link, linktext = match(str, "^%[%[([^|%]]+)%|?(.-)%]%]")
if link then
is_vowel = find(linktext ~= "" and linktext or link, "^[AEIOUaeiou]")
else
is_vowel = find(str, "^[AEIOUaeiou]")
end
return is_vowel and (ucfirst and "An" or "an") or (ucfirst and "A" or "a")
end
get_indefinite_article = export.get_indefinite_article
--[==[
Prefix `text` with the appropriate indefinite article to prefix to `text`. Correctly handles links and capitalized
text. Does not correctly handle words like [[union]], [[uniform]] and [[university]] that take "a" despite beginning
with a 'u'. The returned article will have its first letter capitalized if `ucfirst` is specified, otherwise lowercase.
]==]
function export.add_indefinite_article(text, ucfirst)
return get_indefinite_article(text, ucfirst) .. " " .. text
end
return export