Modul:String

--[[
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.
Unit tests for this module are available at Module:String/tests.
]]
localstr={}
--[[
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.
]]
functionstr.len(frame)
localnew_args=str._getParameters(frame.args,{'s'})
locals=new_args['s']or''
returnmw.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.
]]
functionstr.sub(frame)
localnew_args=str._getParameters(frame.args,{'s','i','j'})
locals=new_args['s']or''
locali=tonumber(new_args['i'])or1
localj=tonumber(new_args['j'])or-1
locallen=mw.ustring.len(s)
-- Convert negatives for range checking
ifi<0then
i=len+i+1
end
ifj<0then
j=len+j+1
end
ifi>lenorj>lenori<1orj<1then
returnstr._error('String subset index out of range')
end
ifj<ithen
returnstr._error('String subset indices out of order')
end
returnmw.ustring.sub(s,i,j)
end
--[[
This function implements that features of {{str sub old}} and is kept in order
to maintain these older templates.
]]
functionstr.sublength(frame)
locali=tonumber(frame.args.i)or0
locallen=tonumber(frame.args.len)
returnmw.ustring.sub(frame.args.s,i+1,lenand(i+len))
end
--[[
_match
This function returns a substring from the source string that matches a
specified pattern. It is exported for use in other modules
Usage:
strmatch = require("Module:String")._match
sresult = strmatch( s, pattern, start, match, plain, nomatch )
Parameters
    s: The string to search
    pattern: The pattern or string to find within the string
    start: The index within the source string to start the search.  The first
        character of the string has index 1.  Defaults to 1.
    match: In some cases it may be possible to make multiple matches on a single
        string.  This specifies which match to return, where the first match is
        match= 1.  If a negative number is specified then a match is returned
        counting from the last match.  Hence match = -1 is the same as requesting
        the last match.  Defaults to 1.
    plain: A flag indicating that the pattern should be understood as plain
        text.  Defaults to false.
    nomatch: If no match is found, output the "nomatch" value rather than an error.
For information on constructing Lua patterns, a form of [regular expression], see:
* http://www.lua.org/manual/5.1/manual.html#5.4.1
* http://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#Patterns
* http://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#Ustring_patterns
]]
-- This sub-routine is exported for use in other modules
functionstr._match(s,pattern,start,match_index,plain_flag,nomatch)
ifs==''then
returnstr._error('Target string is empty')
end
ifpattern==''then
returnstr._error('Pattern string is empty')
end
start=tonumber(start)or1
ifmath.abs(start)<1ormath.abs(start)>mw.ustring.len(s)then
returnstr._error('Requested start is out of range')
end
ifmatch_index==0then
returnstr._error('Match index is out of range')
end
ifplain_flagthen
pattern=str._escapePattern(pattern)
end
localresult
ifmatch_index==1then
-- Find first match is simple case
result=mw.ustring.match(s,pattern,start)
else
ifstart>1then
s=mw.ustring.sub(s,start)
end
localiterator=mw.ustring.gmatch(s,pattern)
ifmatch_index>0then
-- Forward search
forwiniteratordo
match_index=match_index-1
ifmatch_index==0then
result=w
break
end
end
else
-- Reverse search
localresult_table={}
localcount=1
forwiniteratordo
result_table[count]=w
count=count+1
end
result=result_table[count+match_index]
end
end
ifresult==nilthen
ifnomatch==nilthen
returnstr._error('Match not found')
else
returnnomatch
end
else
returnresult
end
end
--[[
match
This function returns a substring from the source string that matches a
specified pattern.
Usage:
{{#invoke:String|match|source_string|pattern_string|start_index|match_number|plain_flag|nomatch_output}}
OR
{{#invoke:String|match|s=source_string|pattern=pattern_string|start=start_index
    |match=match_number|plain=plain_flag|nomatch=nomatch_output}}
Parameters
    s: The string to search
    pattern: The pattern or string to find within the string
    start: The index within the source string to start the search.  The first
        character of the string has index 1.  Defaults to 1.
    match: In some cases it may be possible to make multiple matches on a single
        string.  This specifies which match to return, where the first match is
        match= 1.  If a negative number is specified then a match is returned
        counting from the last match.  Hence match = -1 is the same as requesting
        the last match.  Defaults to 1.
    plain: A flag indicating that the pattern should be understood as plain
        text.  Defaults to false.
    nomatch: If no match is found, output the "nomatch" value rather than an error.
If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from each string.  In some circumstances this is desirable, in
other cases one may want to preserve the whitespace.
If the match_number or start_index are out of range for the string being queried, then
this function generates an error.  An error is also generated if no match is found.
If one adds the parameter ignore_errors=true, then the error will be suppressed and
an empty string will be returned on any failure.
For information on constructing Lua patterns, a form of [regular expression], see:
* http://www.lua.org/manual/5.1/manual.html#5.4.1
* http://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#Patterns
* http://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#Ustring_patterns
]]
-- This is the entry point for #invoke:String|match
functionstr.match(frame)
localnew_args=str._getParameters(frame.args,{'s','pattern','start','match','plain','nomatch'})
locals=new_args['s']or''
localstart=tonumber(new_args['start'])or1
localplain_flag=str._getBoolean(new_args['plain']orfalse)
localpattern=new_args['pattern']or''
localmatch_index=math.floor(tonumber(new_args['match'])or1)
localnomatch=new_args['nomatch']
returnstr._match(s,pattern,start,match_index,plain_flag,nomatch)
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.
]]
functionstr.pos(frame)
localnew_args=str._getParameters(frame.args,{'target','pos'})
localtarget_str=new_args['target']or''
localpos=tonumber(new_args['pos'])or0
ifpos==0ormath.abs(pos)>mw.ustring.len(target_str)then
returnstr._error('String index out of range')
end
returnmw.ustring.sub(target_str,pos,pos)
end
--[[
str_find
This function duplicates the behavior of {{str_find}}, including all of its quirks.
This is provided in order to support existing templates, but is NOT RECOMMENDED for
new code and templates.  New code is recommended to use the "find" function instead.
Returns the first index in "source" that is a match to "target".  Indexing is 1-based,
and the function returns -1 if the "target" string is not present in "source".
Important Note: If the "target" string is empty / missing, this function returns a
value of "1", which is generally unexpected behavior, and must be accounted for
separatetly.
]]
functionstr.str_find(frame)
localnew_args=str._getParameters(frame.args,{'source','target'})
localsource_str=new_args['source']or''
localtarget_str=new_args['target']or''
iftarget_str==''then
return1
end
localstart=mw.ustring.find(source_str,target_str,1,true)
ifstart==nilthen
start=-1
end
returnstart
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.
]]
functionstr.find(frame)
localnew_args=str._getParameters(frame.args,{'source','target','start','plain'})
localsource_str=new_args['source']or''
localpattern=new_args['target']or''
localstart_pos=tonumber(new_args['start'])or1
localplain=new_args['plain']ortrue
ifsource_str==''orpattern==''then
return0
end
plain=str._getBoolean(plain)
localstart=mw.ustring.find(source_str,pattern,start_pos,plain)
ifstart==nilthen
start=0
end
returnstart
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
]]
functionstr.replace(frame)
localnew_args=str._getParameters(frame.args,{'source','pattern','replace','count','plain'})
localsource_str=new_args['source']or''
localpattern=new_args['pattern']or''
localreplace=new_args['replace']or''
localcount=tonumber(new_args['count'])
localplain=new_args['plain']ortrue
ifsource_str==''orpattern==''then
returnsource_str
end
plain=str._getBoolean(plain)
ifplainthen
pattern=str._escapePattern(pattern)
replace=string.gsub(replace,"%%","%%%%")--Only need to escape replacement sequences.
end
localresult
ifcount~=nilthen
result=mw.ustring.gsub(source_str,pattern,replace,count)
else
result=mw.ustring.gsub(source_str,pattern,replace)
end
returnresult
end
--[[
    simple function to pipe string.rep to templates.
]]
functionstr.rep(frame)
localrepetitions=tonumber(frame.args[2])
ifnotrepetitionsthen
returnstr._error('function rep expects a number as second parameter, received "'..(frame.args[2]or'')..'"')
end
returnstring.rep(frame.args[1]or'',repetitions)
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.
]]
functionstr.escapePattern(frame)
localpattern_str=frame.args[1]
ifnotpattern_strthen
returnstr._error('No pattern string specified')
end
localresult=str._escapePattern(pattern_str)
returnresult
end
--[[
count
This function counts the number of occurrences of one string in another.
]]
functionstr.count(frame)
localargs=str._getParameters(frame.args,{'source','pattern','plain'})
localsource=args.sourceor''
localpattern=args.patternor''
localplain=str._getBoolean(args.plainortrue)
ifplainthen
pattern=str._escapePattern(pattern)
end
local_,count=mw.ustring.gsub(source,pattern,'')
returncount
end
--[[
endswith
This function determines whether a string ends with another string.
]]
functionstr.endswith(frame)
localargs=str._getParameters(frame.args,{'source','pattern'})
localsource=args.sourceor''
localpattern=args.patternor''
ifpattern==''then
-- All strings end with the empty string.
return"yes"
end
ifmw.ustring.sub(source,-mw.ustring.len(pattern),-1)==patternthen
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}}
]]
functionstr.join(frame)
localargs={}
localsep
for_,vinipairs(frame.args)do
ifsepthen
ifv~=''then
table.insert(args,v)
end
else
sep=v
end
end
returntable.concat(args,sepor'')
end
-- findpagetext returns the position of a piece of text in a page
-- First positional parameter or |text is the search text
-- Optional parameter |title is the page title, defaults to current page
-- Optional parameter |plain is either true for plain search (default) or false for Lua pattern search
-- Optional parameter |nomatch is the return value when no match is found; default is nil
functionstr._findpagetext(args)
-- process parameters
localnomatch=args.nomatchor""
ifnomatch==""thennomatch=nilend
--
localtext=mw.text.trim(args[1]orargs.textor"")
iftext==""thenreturnnilend
--
localtitle=args.titleor""
localtitleobj
iftitle==""then
titleobj=mw.title.getCurrentTitle()
else
titleobj=mw.title.new(title)
end
--
localplain=args.plainor""
ifplain:sub(1,1)=="f"thenplain=falseelseplain=trueend
-- get the page content and look for 'text' - return position or nomatch
localcontent=titleobjandtitleobj:getContent()
returncontentandmw.ustring.find(content,text,1,plain)ornomatch
end
functionstr.findpagetext(frame)
localargs=frame.args
localpargs=frame:getParent().args
fork,vinpairs(pargs)do
args[k]=v
end
ifnot(args[1]orargs.text)thenreturnnilend
-- just the first value
return(str._findpagetext(args))
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.
]]
functionstr._getParameters(frame_args,arg_list)
localnew_args={}
localindex=1
localvalue
for_,arginipairs(arg_list)do
value=frame_args[arg]
ifvalue==nilthen
value=frame_args[index]
index=index+1
end
new_args[arg]=value
end
returnnew_args
end
--[[
Helper function to handle error messages.
]]
functionstr._error(error_str)
localframe=mw.getCurrentFrame()
localerror_category=frame.args.error_categoryor'Errors reported by Module String'
localignore_errors=frame.args.ignore_errorsorfalse
localno_category=frame.args.no_categoryorfalse
ifstr._getBoolean(ignore_errors)then
return''
end
localerror_str='<strong class="error">String Module Error: '..error_str..'</strong>'
iferror_category~=''andnotstr._getBoolean(no_category)then
error_str='[[Category:'..error_category..']]'..error_str
end
returnerror_str
end
--[[
Helper Function to interpret boolean strings
]]
functionstr._getBoolean(boolean_str)
localboolean_value
iftype(boolean_str)=='string'then
boolean_str=boolean_str:lower()
ifboolean_str=='false'orboolean_str=='no'orboolean_str=='0'
orboolean_str==''then
boolean_value=false
else
boolean_value=true
end
elseiftype(boolean_str)=='boolean'then
boolean_value=boolean_str
else
error('No boolean value found')
end
returnboolean_value
end
--[[
Helper function that escapes all pattern characters so that they will be treated
as plain text.
]]
functionstr._escapePattern(pattern_str)
return(string.gsub(pattern_str,"[%(%)%.%%%+%-%*%?%[%^%$%]]","%%%0"))
end
returnstr