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Module:String: Difference between revisions

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


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--[[
--[[
match
_match


This function returns a substring from the source string that matches a
This function returns a substring from the source string that matches a
specified pattern.
specified pattern. It is exported for use in other modules


Usage:
Usage:
{{#invoke:String|match|source_string|pattern_string|start_index|match_number|plain_flag|nomatch_output}}
strmatch = require("Module:String")._match
OR
sresult = strmatch( s, pattern, start, match, plain, nomatch )
{{#invoke:String|match|s=source_string|pattern=pattern_string|start=start_index
    |match=match_number|plain=plain_flag|nomatch=nomatch_output}}


Parameters
Parameters
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         text.  Defaults to false.
         text.  Defaults to false.
     nomatch: If no match is found, output the "nomatch" value rather than an error.
     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:
For information on constructing Lua patterns, a form of [regular expression], see:
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end
end
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
-- This is the entry point for #invoke:String|match
function str.match( frame )
function str.match( frame )
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if plain then
if plain then
pattern = str._escapePattern( pattern )
pattern = str._escapePattern( pattern )
replace = mw.ustring.gsub( replace, "%%", "%%%%" ) --Only need to escape replacement sequences.
replace = string.gsub( replace, "%%", "%%%%" ) --Only need to escape replacement sequences.
end
end


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end
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
function str._findpagetext(args)
-- process parameters
local nomatch = args.nomatch or ""
if nomatch == "" then nomatch = nil end
--
local text = mw.text.trim(args[1] or args.text or "")
if text == "" then return nil end
--
local title = args.title or ""
local titleobj
if title == "" then
titleobj = mw.title.getCurrentTitle()
else
titleobj = mw.title.new(title)
end
--
local plain = args.plain or ""
if plain:sub(1, 1) == "f" then plain = false else plain = true end
-- get the page content and look for 'text' - return position or nomatch
local content = titleobj and titleobj:getContent()
return content and mw.ustring.find(content, text, 1, plain) or nomatch
end
function str.findpagetext(frame)
local args = frame.args
local pargs = frame:getParent().args
for k, v in pairs(pargs) do
args[k] = v
end
if not (args[1] or args.text) then return nil end
-- 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
Helper function that populates the argument list given that user may need to use a mix of
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]]
]]
function str._escapePattern( pattern_str )
function str._escapePattern( pattern_str )
return mw.ustring.gsub( pattern_str, "([%(%)%.%%%+%-%*%?%[%^%$%]])", "%%%1" )
return ( string.gsub( pattern_str, "[%(%)%.%%%+%-%*%?%[%^%$%]]", "%%%0" ) )
end
end


return str
return str
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