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| --[[
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|
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| This module is intended to provide access to basic string functions.
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|
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| Most of the functions provided here can be invoked with named parameters,
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| unnamed parameters, or a mixture. If named parameters are used, Mediawiki will
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| automatically remove any leading or trailing whitespace from the parameter.
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| Depending on the intended use, it may be advantageous to either preserve or
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| remove such whitespace.
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|
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| Global options
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| ignore_errors: If set to 'true' or 1, any error condition will result in
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| an empty string being returned rather than an error message.
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|
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| error_category: If an error occurs, specifies the name of a category to
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| include with the error message. The default category is
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| [Category:Errors reported by Module String].
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|
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| no_category: If set to 'true' or 1, no category will be added if an error
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| is generated.
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|
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| Unit tests for this module are available at Module:String/tests.
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| ]]
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|
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| local str = {} | | local str = {} |
|
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|
| --[[
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| len
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|
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| This function returns the length of the target string.
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|
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| Usage:
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| {{#invoke:String|len|target_string|}}
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| OR
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| {{#invoke:String|len|s=target_string}}
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|
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| Parameters
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| s: The string whose length to report
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|
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| If invoked using named parameters, Mediawiki will automatically remove any leading or
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| trailing whitespace from the target string.
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| ]]
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| function str.len( frame ) | | function str.len( frame ) |
| local new_args = str._getParameters( frame.args, {'s'} )
| | return mw.ustring.len( frame.args.s ) |
| local s = new_args['s'] or ''
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| return mw.ustring.len( s )
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| end | | end |
|
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|
| --[[
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| sub
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|
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| This function returns a substring of the target string at specified indices.
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|
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| Usage:
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| {{#invoke:String|sub|target_string|start_index|end_index}}
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| OR
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| {{#invoke:String|sub|s=target_string|i=start_index|j=end_index}}
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|
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| Parameters
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| s: The string to return a subset of
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| i: The fist index of the substring to return, defaults to 1.
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| j: The last index of the string to return, defaults to the last character.
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|
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| The first character of the string is assigned an index of 1. If either i or j
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| is a negative value, it is interpreted the same as selecting a character by
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| counting from the end of the string. Hence, a value of -1 is the same as
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| selecting the last character of the string.
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|
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| If the requested indices are out of range for the given string, an error is
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| reported.
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| ]]
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| function str.sub( frame ) | | function str.sub( frame ) |
| local new_args = str._getParameters( frame.args, { 's', 'i', 'j' } )
| | return mw.ustring.sub( frame.args.s, tonumber( frame.args.i ), tonumber( frame.args.i ) ) |
| local s = new_args['s'] or ''
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| local i = tonumber( new_args['i'] ) or 1
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| local j = tonumber( new_args['j'] ) or -1
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| | |
| local len = mw.ustring.len( s )
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| | |
| -- Convert negatives for range checking
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| if i < 0 then
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| i = len + i + 1
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| end
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| if j < 0 then
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| j = len + j + 1
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| end
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| | |
| if i > len or j > len or i < 1 or j < 1 then
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| return str._error( 'String subset index out of range' )
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| end
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| if j < i then
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| return str._error( 'String subset indices out of order' )
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| end
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| | |
| return mw.ustring.sub( s, i, j )
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| end
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| | |
| --[[
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| This function implements that features of {{str sub old}} and is kept in order
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| to maintain these older templates.
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| ]]
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| function str.sublength( frame )
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| local i = tonumber( frame.args.i ) or 0
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| local len = tonumber( frame.args.len )
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| return mw.ustring.sub( frame.args.s, i + 1, len and ( i + len ) )
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| end | | end |
|
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|
| --[[
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| _match
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|
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| This function returns a substring from the source string that matches a
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| specified pattern. It is exported for use in other modules
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|
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| Usage:
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| strmatch = require("Module:String")._match
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| sresult = strmatch( s, pattern, start, match, plain, nomatch )
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|
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| Parameters
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| s: The string to search
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| pattern: The pattern or string to find within the string
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| start: The index within the source string to start the search. The first
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| character of the string has index 1. Defaults to 1.
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| match: In some cases it may be possible to make multiple matches on a single
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| string. This specifies which match to return, where the first match is
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| match= 1. If a negative number is specified then a match is returned
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| counting from the last match. Hence match = -1 is the same as requesting
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| the last match. Defaults to 1.
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| plain: A flag indicating that the pattern should be understood as plain
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| text. Defaults to false.
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| nomatch: If no match is found, output the "nomatch" value rather than an error.
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|
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| For information on constructing Lua patterns, a form of [regular expression], see:
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|
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| * http://www.lua.org/manual/5.1/manual.html#5.4.1
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| * http://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#Patterns
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| * http://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#Ustring_patterns
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|
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| ]]
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| -- This sub-routine is exported for use in other modules
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| function str._match( s, pattern, start, match_index, plain_flag, nomatch )
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| if s == '' then
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| return str._error( 'Target string is empty' )
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| end
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| if pattern == '' then
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| return str._error( 'Pattern string is empty' )
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| end
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| start = tonumber(start) or 1
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| if math.abs(start) < 1 or math.abs(start) > mw.ustring.len( s ) then
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| return str._error( 'Requested start is out of range' )
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| end
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| if match_index == 0 then
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| return str._error( 'Match index is out of range' )
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| end
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| if plain_flag then
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| pattern = str._escapePattern( pattern )
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| end
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|
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| local result
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| if match_index == 1 then
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| -- Find first match is simple case
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| result = mw.ustring.match( s, pattern, start )
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| else
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| if start > 1 then
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| s = mw.ustring.sub( s, start )
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| end
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|
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| local iterator = mw.ustring.gmatch(s, pattern)
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| if match_index > 0 then
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| -- Forward search
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| for w in iterator do
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| match_index = match_index - 1
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| if match_index == 0 then
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| result = w
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| break
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| end
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| end
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| else
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| -- Reverse search
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| local result_table = {}
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| local count = 1
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| for w in iterator do
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| result_table[count] = w
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| count = count + 1
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| end
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|
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| result = result_table[ count + match_index ]
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| end
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| end
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|
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| if result == nil then
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| if nomatch == nil then
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| return str._error( 'Match not found' )
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| else
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| return nomatch
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| end
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| else
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| return result
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| end
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| end
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|
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| --[[
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| match
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|
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| This function returns a substring from the source string that matches a
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| specified pattern.
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|
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| Usage:
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| {{#invoke:String|match|source_string|pattern_string|start_index|match_number|plain_flag|nomatch_output}}
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| OR
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| {{#invoke:String|match|s=source_string|pattern=pattern_string|start=start_index
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| |match=match_number|plain=plain_flag|nomatch=nomatch_output}}
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|
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| Parameters
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| s: The string to search
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| pattern: The pattern or string to find within the string
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| start: The index within the source string to start the search. The first
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| character of the string has index 1. Defaults to 1.
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| match: In some cases it may be possible to make multiple matches on a single
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| string. This specifies which match to return, where the first match is
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| match= 1. If a negative number is specified then a match is returned
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| counting from the last match. Hence match = -1 is the same as requesting
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| the last match. Defaults to 1.
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| plain: A flag indicating that the pattern should be understood as plain
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| text. Defaults to false.
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| nomatch: If no match is found, output the "nomatch" value rather than an error.
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|
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| If invoked using named parameters, Mediawiki will automatically remove any leading or
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| trailing whitespace from each string. In some circumstances this is desirable, in
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| other cases one may want to preserve the whitespace.
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|
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| If the match_number or start_index are out of range for the string being queried, then
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| this function generates an error. An error is also generated if no match is found.
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| If one adds the parameter ignore_errors=true, then the error will be suppressed and
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| an empty string will be returned on any failure.
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|
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| For information on constructing Lua patterns, a form of [regular expression], see:
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|
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| * http://www.lua.org/manual/5.1/manual.html#5.4.1
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| * http://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#Patterns
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| * http://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#Ustring_patterns
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|
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| ]]
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| -- This is the entry point for #invoke:String|match
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| function str.match( frame ) | | function str.match( frame ) |
| local new_args = str._getParameters( frame.args, {'s', 'pattern', 'start', 'match', 'plain', 'nomatch'} )
| | return mw.ustring.match( frame.args.s, frame.args.pattern, tonumber( frame.args.i ) ) |
| local s = new_args['s'] or ''
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| local start = tonumber( new_args['start'] ) or 1
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| local plain_flag = str._getBoolean( new_args['plain'] or false )
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| local pattern = new_args['pattern'] or ''
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| local match_index = math.floor( tonumber(new_args['match']) or 1 )
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| local nomatch = new_args['nomatch']
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| | |
| return str._match( s, pattern, start, match_index, plain_flag, nomatch )
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| end
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| | |
| --[[
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| pos
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| This function returns a single character from the target string at position pos.
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| Usage:
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| {{#invoke:String|pos|target_string|index_value}}
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| OR
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| {{#invoke:String|pos|target=target_string|pos=index_value}}
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| | |
| Parameters
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| target: The string to search
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| pos: The index for the character to return | |
| | |
| If invoked using named parameters, Mediawiki will automatically remove any leading or
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| trailing whitespace from the target string. In some circumstances this is desirable, in
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| other cases one may want to preserve the whitespace.
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| | |
| The first character has an index value of 1.
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| If one requests a negative value, this function will select a character by counting backwards
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| from the end of the string. In other words pos = -1 is the same as asking for the last character.
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| A requested value of zero, or a value greater than the length of the string returns an error.
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| ]]
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| function str.pos( frame )
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| local new_args = str._getParameters( frame.args, {'target', 'pos'} )
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| local target_str = new_args['target'] or ''
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| local pos = tonumber( new_args['pos'] ) or 0
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| | |
| if pos == 0 or math.abs(pos) > mw.ustring.len( target_str ) then
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| return str._error( 'String index out of range' )
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| end
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| return mw.ustring.sub( target_str, pos, pos )
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| end
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| | |
| --[[
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| str_find
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| This function duplicates the behavior of {{str_find}}, including all of its quirks.
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| This is provided in order to support existing templates, but is NOT RECOMMENDED for
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| new code and templates. New code is recommended to use the "find" function instead.
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| Returns the first index in "source" that is a match to "target". Indexing is 1-based,
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| and the function returns -1 if the "target" string is not present in "source".
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| Important Note: If the "target" string is empty / missing, this function returns a
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| value of "1", which is generally unexpected behavior, and must be accounted for
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| separatetly.
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| ]]
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| function str.str_find( frame )
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| local new_args = str._getParameters( frame.args, {'source', 'target'} )
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| local source_str = new_args['source'] or ''
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| local target_str = new_args['target'] or ''
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| | |
| if target_str == '' then
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| return 1
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| end
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| | |
| local start = mw.ustring.find( source_str, target_str, 1, true )
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| if start == nil then
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| start = -1
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| end
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| return start
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| end
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| | |
| --[[
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| find
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| This function allows one to search for a target string or pattern within another
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| string.
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| Usage:
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| {{#invoke:String|find|source_str|target_string|start_index|plain_flag}}
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| OR
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| {{#invoke:String|find|source=source_str|target=target_str|start=start_index|plain=plain_flag}}
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| | |
| Parameters
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| source: The string to search
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| target: The string or pattern to find within source
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| start: The index within the source string to start the search, defaults to 1
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| plain: Boolean flag indicating that target should be understood as plain
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| text and not as a Lua style regular expression, defaults to true
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| | |
| If invoked using named parameters, Mediawiki will automatically remove any leading or
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| trailing whitespace from the parameter. In some circumstances this is desirable, in
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| other cases one may want to preserve the whitespace.
| |
| | |
| This function returns the first index >= "start" where "target" can be found
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| within "source". Indices are 1-based. If "target" is not found, then this
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| function returns 0. If either "source" or "target" are missing / empty, this
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| function also returns 0.
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| This function should be safe for UTF-8 strings.
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| ]]
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| function str.find( frame )
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| local new_args = str._getParameters( frame.args, {'source', 'target', 'start', 'plain' } )
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| local source_str = new_args['source'] or ''
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| local pattern = new_args['target'] or ''
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| local start_pos = tonumber(new_args['start']) or 1
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| local plain = new_args['plain'] or true
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| | |
| if source_str == '' or pattern == '' then
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| return 0
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| end
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| plain = str._getBoolean( plain )
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| | |
| local start = mw.ustring.find( source_str, pattern, start_pos, plain )
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| if start == nil then
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| start = 0
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| end
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| return start
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| end
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| | |
| --[[
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| replace
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| This function allows one to replace a target string or pattern within another
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| string.
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| Usage:
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| {{#invoke:String|replace|source_str|pattern_string|replace_string|replacement_count|plain_flag}}
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| OR
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| {{#invoke:String|replace|source=source_string|pattern=pattern_string|replace=replace_string|
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| count=replacement_count|plain=plain_flag}}
| |
| | |
| Parameters
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| source: The string to search
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| pattern: The string or pattern to find within source
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| replace: The replacement text
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| count: The number of occurences to replace, defaults to all.
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| plain: Boolean flag indicating that pattern should be understood as plain
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| text and not as a Lua style regular expression, defaults to true
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| ]]
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| function str.replace( frame )
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| local new_args = str._getParameters( frame.args, {'source', 'pattern', 'replace', 'count', 'plain' } )
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| local source_str = new_args['source'] or ''
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| local pattern = new_args['pattern'] or ''
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| local replace = new_args['replace'] or ''
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| local count = tonumber( new_args['count'] )
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| local plain = new_args['plain'] or true
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| | |
| if source_str == '' or pattern == '' then
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| return source_str
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| end
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| plain = str._getBoolean( plain )
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| | |
| if plain then
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| pattern = str._escapePattern( pattern )
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| replace = mw.ustring.gsub( replace, "%%", "%%%%" ) --Only need to escape replacement sequences.
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| end
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| | |
| local result
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| | |
| if count ~= nil then
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| result = mw.ustring.gsub( source_str, pattern, replace, count )
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| else
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| result = mw.ustring.gsub( source_str, pattern, replace )
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| end
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| | |
| return result
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| end
| |
| | |
| --[[
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| simple function to pipe string.rep to templates.
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| ]]
| |
| function str.rep( frame )
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| local repetitions = tonumber( frame.args[2] )
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| if not repetitions then
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| return str._error( 'function rep expects a number as second parameter, received "' .. ( frame.args[2] or '' ) .. '"' )
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| end
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| return string.rep( frame.args[1] or '', repetitions )
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| end
| |
| | |
| --[[
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| escapePattern
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| | |
| This function escapes special characters from a Lua string pattern. See [1]
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| for details on how patterns work.
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| | |
| [1] https://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#Patterns
| |
| | |
| Usage:
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| {{#invoke:String|escapePattern|pattern_string}}
| |
| | |
| Parameters
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| pattern_string: The pattern string to escape.
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| ]]
| |
| function str.escapePattern( frame )
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| local pattern_str = frame.args[1]
| |
| if not pattern_str then
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| return str._error( 'No pattern string specified' )
| |
| end
| |
| local result = str._escapePattern( pattern_str )
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| return result
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| end
| |
| | |
| --[[
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| count
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| This function counts the number of occurrences of one string in another.
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| ]]
| |
| function str.count(frame)
| |
| local args = str._getParameters(frame.args, {'source', 'pattern', 'plain'})
| |
| local source = args.source or ''
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| local pattern = args.pattern or ''
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| local plain = str._getBoolean(args.plain or true)
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| if plain then
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| pattern = str._escapePattern(pattern)
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| end
| |
| local _, count = mw.ustring.gsub(source, pattern, '')
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| return count
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| end
| |
| | |
| --[[
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| endswith
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| This function determines whether a string ends with another string.
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| ]]
| |
| function str.endswith(frame)
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| local args = str._getParameters(frame.args, {'source', 'pattern'})
| |
| local source = args.source or ''
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| local pattern = args.pattern or ''
| |
| if pattern == '' then
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| -- All strings end with the empty string.
| |
| return "yes"
| |
| end
| |
| if mw.ustring.sub(source, -mw.ustring.len(pattern), -1) == pattern then
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| return "yes"
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| else
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| return ""
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| end
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| end
| |
| | |
| --[[
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| join
| |
| | |
| Join all non empty arguments together; the first argument is the separator.
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| Usage:
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| {{#invoke:String|join|sep|one|two|three}}
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| ]]
| |
| function str.join(frame)
| |
| local args = {}
| |
| local sep
| |
| for _, v in ipairs( frame.args ) do
| |
| if sep then
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| if v ~= '' then
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| table.insert(args, v)
| |
| end
| |
| else
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| 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
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| named and unnamed parameters. This is relevant because named parameters are not
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| identical to unnamed parameters due to string trimming, and when dealing with strings
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| 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
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| value = frame_args[arg]
| |
| if value == nil then
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| value = frame_args[index]
| |
| index = index + 1
| |
| end
| |
| new_args[arg] = value
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| end
| |
| | |
| return new_args
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| end
| |
| | |
| --[[
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| 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
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| 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 | | end |
|
| |
|
| return str | | return str |