Module:string utilities
Documentation for this module may be created at Module:string utilities/doc
local module_name = "string_utilities"
local export = {}
local rfind = mw.ustring.find
local format_escapes = {
["op"] = "{",
["cl"] = "}",
}
function export.format(str, tbl)
return (string.gsub(str, "{(\\?)((\\?)[^{}]*)}", function (p1, name, p2)
if #p1 + #p2 == 1 then
return format_escapes[name] or error(module_name .. ".format: unrecognized escape sequence '{\\" .. name .. "}'")
else
if tbl[name] and type(tbl[name]) ~= "string" then
error(module_name .. ".format: '" .. name .. "' is a " .. type(tbl[name]) .. ", not a string")
end
return tbl[name] or error(module_name .. ".format: '" .. name .. "' not found in table")
end
end))
end
-- Reimplementation of mw.ustring.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).
function export.capturing_split(str, pattern)
local ret = {}
-- (.-) corresponds to (.*?) in Python or Perl; () captures the
-- current position after matching.
pattern = "(.-)" .. pattern .. "()"
local start = 1
while true do
-- Did we reach the end of the string?
if start > #str then
table.insert(ret, "")
return ret
end
-- match() returns all captures as multiple return values;
-- we need to insert into a table to get them all.
local captures = {mw.ustring.match(str, pattern, start)}
-- If no match, add the remainder of the string.
if #captures == 0 then
table.insert(ret, mw.ustring.sub(str, start))
return ret
end
local newstart = table.remove(captures)
-- Special case: If we don't advance by any characters, then advance
-- by one character; this avoids an infinite loop, and makes splitting
-- by an empty string work the way mw.ustring.split() does. If we
-- reach the end of the string this way, return immediately, so we
-- don't get a final empty string.
if newstart == start then
table.insert(ret, mw.ustring.sub(str, start, start))
table.remove(captures, 1)
start = start + 1
if start > #str then
return ret
end
else
table.insert(ret, table.remove(captures, 1))
start = newstart
end
-- Insert any captures from the splitting pattern.
for _, x in ipairs(captures) do
table.insert(ret, x)
end
end
end
local function uclcfirst(text, dolower)
local function douclcfirst(text)
-- Actual function to re-case of the first letter.
local first_letter = mw.ustring.sub(text, 1, 1)
first_letter = dolower and mw.ustring.lower(first_letter) or mw.ustring.upper(first_letter)
return first_letter .. mw.ustring.sub(text, 2)
end
-- 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 = mw.ustring.match(text, "^%[%[([^|%]]+)%|?(.-)%]%](.*)$")
if link then
return "[[" .. link .. "|" .. douclcfirst(linktext ~= "" and linktext or link) .. "]]" .. remainder
end
return douclcfirst(text)
end
function export.ucfirst(text)
return uclcfirst(text, false)
end
function export.lcfirst(text)
return uclcfirst(text, true)
end
function export.pluralize(text)
if type(text) == "table" then
-- allow calling from a template
text = text.args[1]
end
-- Pluralize a word in a smart fashion, according to normal English rules.
-- 1. If word ends in consonant + -y, replace the -y with -ies.
-- 2. If the word ends in -s, -x, -z, -sh, -ch, add -es.
-- 3. Otherwise, add -s.
-- This handles links correctly:
-- 1. If a piped link, change the second part appropriately.
-- 2. If a non-piped link and rule #1 above applies, convert to a piped link
-- with the second part containing the plural.
-- 3. If a non-piped link and rules #2 or #3 above apply, add the plural
-- outside the link.
local function word_ends_in_consonant_plus_y(text)
-- FIXME, a subrule of rule #1 above says the -ies ending doesn't
-- apply to proper nouns, hence "the Gettys", "the public Ivys".
-- We should maybe consider applying this rule here; but it may not
-- be important as this function is almost always called on common nouns
-- (e.g. parts of speech, place types).
return text:find("[^aeiouAEIOU ]y$")
end
local function word_takes_es_plural(text)
return text:find("[sxz]$") or text:find("[cs]h$")
end
local function do_pluralize(text)
if word_ends_in_consonant_plus_y(text) then
-- avoid returning multiple values
local hack_single_retval = text:gsub("y$", "ies")
return hack_single_retval
elseif word_takes_es_plural(text) then
return text .. "es"
else
return text .. "s"
end
end
-- Check for a link. This pattern matches both piped and unpiped links.
-- If the link is not piped, the second capture (linktext) will be empty.
local beginning, link, linktext = mw.ustring.match(text, "^(.*)%[%[([^|%]]+)%|?(.-)%]%]$")
if link then
if linktext ~= "" then
return beginning .. "[[" .. link .. "|" .. do_pluralize(linktext) .. "]]"
end
if word_ends_in_consonant_plus_y(link) then
return beginning .. "[[" .. link .. "|" .. link:gsub("y$", "ies") .. "]]"
end
return beginning .. "[[" .. link .. "]]" .. (word_takes_es_plural(link) and "es" or "s")
end
return do_pluralize(text)
end
function export.singularize(text)
if type(text) == "table" then
-- allow calling from a template
text = text.args[1]
end
-- Singularize a word in a smart fashion, according to normal English rules.
-- Works analogously to pluralize().
-- NOTE: This doesn't always work as well as pluralize(). Beware. It will
-- mishandle cases like "passes" -> "passe", "eyries" -> "eyry".
-- 1. If word ends in -ies, replace -ies with -y.
-- 2. If the word ends in -xes, -shes, -ches, remove -es. [Does not affect
-- -ses, cf. "houses", "impasses".]
-- 3. Otherwise, remove -s.
-- This handles links correctly:
-- 1. If a piped link, change the second part appropriately. Collapse the
-- link to a simple link if both parts end up the same.
-- 2. If a non-piped link, singularize the link.
-- 3. A link like "[[parish]]es" will be handled correctly because the
-- code that checks for -shes etc. allows ] characters between the
-- 'sh' etc. and final -es.
local function do_singularize(text)
local sing = text:match("^(.-)ies$")
if sing then
return sing .. "y"
end
-- Handle cases like "[[parish]]es"
local sing = text:match("^(.-[sc]h%]*)es$")
if sing then
return sing
end
-- Handle cases like "[[box]]es"
local sing = text:match("^(.-x%]*)es$")
if sing then
return sing
end
local sing = text:match("^(.-)s$")
if sing then
return sing
end
return text
end
local function collapse_link(link, linktext)
if link == linktext then
return "[[" .. link .. "]]"
else
return "[[" .. link .. "|" .. linktext .. "]]"
end
end
-- Check for a link. This pattern matches both piped and unpiped links.
-- If the link is not piped, the second capture (linktext) will be empty.
local beginning, link, linktext = mw.ustring.match(text, "^(.*)%[%[([^|%]]+)%|?(.-)%]%]$")
if link then
if linktext ~= "" then
return beginning .. collapse_link(link, do_singularize(linktext))
end
return beginning .. "[[" .. do_singularize(link) .. "]]"
end
return do_singularize(text)
end
function export.add_indefinite_article(text, uppercase)
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, remainder = mw.ustring.match(text, "^%[%[([^|%]]+)%|?(.-)%]%](.*)$")
if link then
is_vowel = rfind(linktext ~= "" and linktext or link, "^[AEIOUaeiou]")
else
is_vowel = rfind(text, "^[AEIOUaeiou]")
end
return (is_vowel and (uppercase and "An " or "an ") or (uppercase and "A " or "a ")) .. text
end
return export