Admin: Tạo trang mới với nội dung “--[[ This module is intended to provide access to basic string functions. Most of the functions provided here can be invoked with named parameters, unnamed parameters, or a mixture. If named parameters are used, Mediawiki will automatically remove any leading or trailing whitespace from the parameter. Depending on the intended use, it may be advantageous to either preserve or remove such whitespace. Global options ignore_errors: If set to 'tr…”

2024-07-29T17:41:35Z

Tạo trang mới với nội dung “--[[ This module is intended to provide access to basic string functions. Most of the functions provided here can be invoked with named parameters, unnamed parameters, or a mixture. If named parameters are used, Mediawiki will automatically remove any leading or trailing whitespace from the parameter. Depending on the intended use, it may be advantageous to either preserve or remove such whitespace. Global options ignore_errors: If set to 'tr…”

Trang mới

--[[

This module is intended to provide access to basic string functions.

Most of the functions provided here can be invoked with named parameters,
unnamed parameters, or a mixture. If named parameters are used, Mediawiki will
automatically remove any leading or trailing whitespace from the parameter.
Depending on the intended use, it may be advantageous to either preserve or
remove such whitespace.

Global options
ignore_errors: If set to 'true' or 1, any error condition will result in
an empty string being returned rather than an error message.

error_category: If an error occurs, specifies the name of a category to
include with the error message. The default category is
[Category:Errors reported by Module String].

no_category: If set to 'true' or 1, no category will be added if an error
is generated.
]]

local str = {}

--[[
len

This function returns the length of the target string.

Usage:
{{#invoke:String|len|target_string|}}
OR
{{#invoke:String|len|s=target_string}}

Parameters
s: The string whose length to report

If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from the target string.
]]
function str.len( frame )
local new_args = str._getParameters( frame.args, {'s'} )
local s = new_args['s'] or ''
return mw.ustring.len( s )
end

--[[
sub

This function returns a substring of the target string at specified indices.

Usage:
{{#invoke:String|sub|target_string|start_index|end_index}}
OR
{{#invoke:String|sub|s=target_string|i=start_index|j=end_index}}

Parameters
s: The string to return a subset of
i: The first index of the substring to return, defaults to 1.
j: The last index of the string to return, defaults to the last character.

The first character of the string is assigned an index of 1. If either i or j
is a negative value, it is interpreted the same as selecting a character by
counting from the end of the string. Hence, a value of -1 is the same as
selecting the last character of the string.

If the requested indices are out of range for the given string, an error is
reported.
]]
function str.sub( frame )
local new_args = str._getParameters( frame.args, { 's', 'i', 'j' } )
local s = new_args['s'] or ''
local i = tonumber( new_args['i'] ) or 1
local j = tonumber( new_args['j'] ) or -1

local len = mw.ustring.len( s )

-- Convert negatives for range checking
if i < 0 then
i = len + i + 1
end
if j < 0 then
j = len + j + 1
end

if i > len or j > len or i < 1 or j < 1 then
return str._error( 'String subset index out of range' )
end
if j < i then
return str._error( 'String subset indices out of order' )
end

return mw.ustring.sub( s, i, j )
end

--[[
pos

This function returns a single character from the target string at position pos.

Usage:
{{#invoke:String|pos|target_string|index_value}}
OR
{{#invoke:String|pos|target=target_string|pos=index_value}}

Parameters
target: The string to search
pos: The index for the character to return

If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from the target string. In some circumstances this is desirable, in
other cases one may want to preserve the whitespace.

The first character has an index value of 1.

If one requests a negative value, this function will select a character by counting backwards
from the end of the string. In other words pos = -1 is the same as asking for the last character.

A requested value of zero, or a value greater than the length of the string returns an error.
]]
function str.pos( frame )
local new_args = str._getParameters( frame.args, {'target', 'pos'} )
local target_str = new_args['target'] or ''
local pos = tonumber( new_args['pos'] ) or 0

if pos == 0 or math.abs(pos) > mw.ustring.len( target_str ) then
return str._error( 'String index out of range' )
end

return mw.ustring.sub( target_str, pos, pos )
end

--[[
find

This function allows one to search for a target string or pattern within another
string.

Usage:
{{#invoke:String|find|source_str|target_string|start_index|plain_flag}}
OR
{{#invoke:String|find|source=source_str|target=target_str|start=start_index|plain=plain_flag}}

Parameters
source: The string to search
target: The string or pattern to find within source
start: The index within the source string to start the search, defaults to 1
plain: Boolean flag indicating that target should be understood as plain
text and not as a Lua style regular expression, defaults to true

If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from the parameter. In some circumstances this is desirable, in
other cases one may want to preserve the whitespace.

This function returns the first index >= "start" where "target" can be found
within "source". Indices are 1-based. If "target" is not found, then this
function returns 0. If either "source" or "target" are missing / empty, this
function also returns 0.

This function should be safe for UTF-8 strings.
]]
function str.find( frame )
local new_args = str._getParameters( frame.args, {'source', 'target', 'start', 'plain' } )
local source_str = new_args['source'] or ''
local pattern = new_args['target'] or ''
local start_pos = tonumber(new_args['start']) or 1
local plain = new_args['plain'] or true

if source_str == '' or pattern == '' then
return 0
end

plain = str._getBoolean( plain )

local start = mw.ustring.find( source_str, pattern, start_pos, plain )
if start == nil then
start = 0
end

return start
end

--[[
replace

This function allows one to replace a target string or pattern within another
string.

Usage:
{{#invoke:String|replace|source_str|pattern_string|replace_string|replacement_count|plain_flag}}
OR
{{#invoke:String|replace|source=source_string|pattern=pattern_string|replace=replace_string|
count=replacement_count|plain=plain_flag}}

Parameters
source: The string to search
pattern: The string or pattern to find within source
replace: The replacement text
count: The number of occurences to replace, defaults to all.
plain: Boolean flag indicating that pattern should be understood as plain
text and not as a Lua style regular expression, defaults to true
]]
function str.replace( frame )
local new_args = str._getParameters( frame.args, {'source', 'pattern', 'replace', 'count', 'plain' } )
local source_str = new_args['source'] or ''
local pattern = new_args['pattern'] or ''
local replace = new_args['replace'] or ''
local count = tonumber( new_args['count'] )
local plain = new_args['plain'] or true

if source_str == '' or pattern == '' then
return source_str
end
plain = str._getBoolean( plain )

if plain then
pattern = str._escapePattern( pattern )
replace = mw.ustring.gsub( replace, "%%", "%%%%" ) --Only need to escape replacement sequences.
end

local result

if count ~= nil then
result = mw.ustring.gsub( source_str, pattern, replace, count )
else
result = mw.ustring.gsub( source_str, pattern, replace )
end

return result
end

--[[
escapePattern

This function escapes special characters from a Lua string pattern. See [1]
for details on how patterns work.

[1] https://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#Patterns

Usage:
{{#invoke:String|escapePattern|pattern_string}}

Parameters
pattern_string: The pattern string to escape.
]]
function str.escapePattern( frame )
local pattern_str = frame.args[1]
if not pattern_str then
return str._error( 'No pattern string specified' )
end
local result = str._escapePattern( pattern_str )
return result
end

--[[
count
This function counts the number of occurrences of one string in another.
]]
function str.count(frame)
local args = str._getParameters(frame.args, {'source', 'pattern', 'plain'})
local source = args.source or ''
local pattern = args.pattern or ''
local plain = str._getBoolean(args.plain or true)
if plain then
pattern = str._escapePattern(pattern)
end
local _, count = mw.ustring.gsub(source, pattern, '')
return count
end

--[[
endswith
This function determines whether a string ends with another string.
]]
function str.endswith(frame)
local args = str._getParameters(frame.args, {'source', 'pattern'})
local source = args.source or ''
local pattern = args.pattern or ''
if pattern == '' then
-- All strings end with the empty string.
return "yes"
end
if mw.ustring.sub(source, -mw.ustring.len(pattern), -1) == pattern then
return "yes"
else
return ""
end
end

--[[
join

Join all non empty arguments together; the first argument is the separator.
Usage:
{{#invoke:String|join|sep|one|two|three}}
]]
function str.join(frame)
local args = {}
local sep
for _, v in ipairs( frame.args ) do
if sep then
if v ~= '' then
table.insert(args, v)
end
else
sep = v
end
end
return table.concat( args, sep or '' )
end

--[[
Helper function that populates the argument list given that user may need to use a mix of
named and unnamed parameters. This is relevant because named parameters are not
identical to unnamed parameters due to string trimming, and when dealing with strings
we sometimes want to either preserve or remove that whitespace depending on the application.
]]
function str._getParameters( frame_args, arg_list )
local new_args = {}
local index = 1
local value

for _, arg in ipairs( arg_list ) do
value = frame_args[arg]
if value == nil then
value = frame_args[index]
index = index + 1
end
new_args[arg] = value
end

return new_args
end

--[[
Helper function to handle error messages.
]]
function str._error( error_str )
local frame = mw.getCurrentFrame()
local error_category = frame.args.error_category or 'Errors reported by Module String'
local ignore_errors = frame.args.ignore_errors or false
local no_category = frame.args.no_category or false

if str._getBoolean(ignore_errors) then
return ''
end

local error_str = '<strong class="error">String Module Error: ' .. error_str .. '</strong>'
if error_category ~= '' and not str._getBoolean( no_category ) then
error_str = '[[Category:' .. error_category .. ']]' .. error_str
end

return error_str
end

--[[
Helper Function to interpret boolean strings
]]
function str._getBoolean( boolean_str )
local boolean_value

if type( boolean_str ) == 'string' then
boolean_str = boolean_str:lower()
if boolean_str == 'false' or boolean_str == 'no' or boolean_str == '0'
or boolean_str == '' then
boolean_value = false
else
boolean_value = true
end
elseif type( boolean_str ) == 'boolean' then
boolean_value = boolean_str
else
error( 'No boolean value found' )
end
return boolean_value
end

--[[
Helper function that escapes all pattern characters so that they will be treated
as plain text.
]]
function str._escapePattern( pattern_str )
return mw.ustring.gsub( pattern_str, "([%(%)%.%%%+%-%*%?%[%^%$%]])", "%%%1" )
end

return str

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