Difference between revisions of "Module:String/sandbox"

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blackwiki>Dinoguy1000
(fix comment; trim trailing whitespace; spaces --> tabs)
blackwiki>Ans
(restore)
Line 1: Line 1:
--[[
+
--[[
  
 
This module is intended to provide access to basic string functions.
 
This module is intended to provide access to basic string functions.
  
Most of the functions provided here can be invoked with named parameters,
+
Most of the functions provided here can be invoked with named parameters,  
unnamed parameters, or a mixture.  If named parameters are used, Mediawiki will
+
unnamed parameters, or a mixture.  If named parameters are used, Mediawiki will  
automatically remove any leading or trailing whitespace from the parameter.
+
automatically remove any leading or trailing whitespace from the parameter.
 
Depending on the intended use, it may be advantageous to either preserve or
 
Depending on the intended use, it may be advantageous to either preserve or
 
remove such whitespace.
 
remove such whitespace.
  
 
Global options
 
Global options
ignore_errors: If set to 'true' or 1, any error condition will result in
+
    ignore_errors: If set to 'true' or 1, any error condition will result in  
an empty string being returned rather than an error message.
+
        an empty string being returned rather than an error message.
 
+
       
error_category: If an error occurs, specifies the name of a category to
+
    error_category: If an error occurs, specifies the name of a category to  
include with the error message.  The default category is
+
        include with the error message.  The default category is
[Category:Errors reported by Module String].
+
        [Category:Errors reported by Module String].
 
+
       
no_category: If set to 'true' or 1, no category will be added if an error
+
    no_category: If set to 'true' or 1, no category will be added if an error
is generated.
+
        is generated.
 
+
       
 
Unit tests for this module are available at Module:String/tests.
 
Unit tests for this module are available at Module:String/tests.
 
]]
 
]]
Line 34: Line 34:
 
OR
 
OR
 
{{#invoke:String|len|s=target_string}}
 
{{#invoke:String|len|s=target_string}}
OR
 
{{#invoke:String|len|string=target_string}}
 
OR
 
{{#invoke:String|len|string_to_detect_length_of=target_string}}
 
  
 
Parameters
 
Parameters
s: The string whose length to report
+
    s: The string whose length to report
  
 
If invoked using named parameters, Mediawiki will automatically remove any leading or
 
If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from the target string.
+
trailing whitespace from the target string.
 
]]
 
]]
 
function str.len( frame )
 
function str.len( frame )
local new_args = str._getParameters( frame.args, {'s'} );
+
    local new_args = str._getParameters( frame.args, {'s'} );
local s = new_args['s'] or '' or 'string' or 'string_to_detect_length_of';
+
    local s = new_args['s'] or '';
return mw.ustring.len( s )
+
    return mw.ustring.len( s )
 
end
 
end
  
Line 62: Line 58:
  
 
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 fist 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.
 
+
   
 
The first character of the string is assigned an index of 1.  If either i or j
 
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
+
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
+
counting from the end of the string.  Hence, a value of -1 is the same as  
 
selecting the last character of the string.
 
selecting the last character of the string.
  
If the requested indices are out of range for the given string, an error is
+
If the requested indices are out of range for the given string, an error is  
 
reported.
 
reported.
 
]]
 
]]
 
function str.sub( frame )
 
function str.sub( frame )
local new_args = str._getParameters( frame.args, { 's', 'i', 'j' } );
+
    local new_args = str._getParameters( frame.args, { 's', 'i', 'j' } );
local s = new_args['s'] or '';
+
    local s = new_args['s'] or '';
local i = tonumber( new_args['i'] ) or 1;
+
    local i = tonumber( new_args['i'] ) or 1;
local j = tonumber( new_args['j'] ) or -1;
+
    local j = tonumber( new_args['j'] ) or -1;
 +
   
 +
    local len = mw.ustring.len( s );
  
local len = mw.ustring.len( s );
+
    -- Convert negatives for range checking
 
+
    if i < 0 then
-- Convert negatives for range checking
+
        i = len + i + 1;
if i < 0 then
+
    end
i = len + i + 1;
+
    if j < 0 then
end
+
        j = len + j + 1;
if j < 0 then
+
    end
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' );
if i > len or j > len or i < 1 or j < 1 then
+
    end
return str._error( 'String subset index out of range' );
+
    if j < i then
end
+
        return str._error( 'String subset indices out of order' );
if j < i then
+
    end
return str._error( 'String subset indices out of order' );
+
   
end
+
    return mw.ustring.sub( s, i, j )
 
 
return mw.ustring.sub( s, i, j )
 
 
end
 
end
  
Line 105: Line 101:
 
]]
 
]]
 
function str.sublength( frame )
 
function str.sublength( frame )
local i = tonumber( frame.args.i ) or 0
+
    local i = tonumber( frame.args.i ) or 0
local len = tonumber( frame.args.len )
+
    local len = tonumber( frame.args.len )
return mw.ustring.sub( frame.args.s, i + 1, len and ( i + len ) )
+
    return mw.ustring.sub( frame.args.s, i + 1, len and ( i + len ) )
 
end
 
end
  
Line 113: Line 109:
 
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.
  
Line 119: Line 115:
 
{{#invoke:String|match|source_string|pattern_string|start_index|match_number|plain_flag|nomatch_output}}
 
{{#invoke:String|match|source_string|pattern_string|start_index|match_number|plain_flag|nomatch_output}}
 
OR
 
OR
{{#invoke:String|match|s=source_string|pattern=pattern_string|start=start_index
+
{{#invoke:String|pos|s=source_string|pattern=pattern_string|start=start_index
|match=match_number|plain=plain_flag|nomatch=nomatch_output}}
+
    |match=match_number|plain=plain_flag|nomatch=nomatch_output}}
  
 
Parameters
 
Parameters
s: The string to search
+
    s: The string to search
pattern: The pattern or string to find within the string
+
    pattern: The pattern or string to find within the string
start: The index within the source string to start the search.  The first
+
    start: The index within the source string to start the search.  The first
character of the string has index 1.  Defaults to 1.
+
        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
+
    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
+
        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
+
        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
+
        counting from the last match.  Hence match = -1 is the same as requesting
the last match.  Defaults to 1.
+
        the last match.  Defaults to 1.
plain: A flag indicating that the pattern should be understood as plain
+
    plain: A flag indicating that the pattern should be understood as plain
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
 
If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from each string.  In some circumstances this is desirable, in
+
trailing whitespace from each string.  In some circumstances this is desirable, in  
 
other cases one may want to preserve the whitespace.
 
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
 
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.
 
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
+
If one adds the parameter ignore_errors=true, then the error will be suppressed and  
 
an empty string will be returned on any failure.
 
an empty string will be returned on any failure.
  
Line 153: Line 149:
 
]]
 
]]
 
function str.match( frame )
 
function str.match( frame )
local new_args = str._getParameters( frame.args, {'s', 'pattern', 'start', 'match', 'plain', 'nomatch'} );
+
    local new_args = str._getParameters( frame.args, {'s', 'pattern', 'start', 'match', 'plain', 'nomatch'} );
local s = new_args['s'] or '';
+
    local s = new_args['s'] or '';
local start = tonumber( new_args['start'] ) or 1;
+
    local start = tonumber( new_args['start'] ) or 1;
local plain_flag = str._getBoolean( new_args['plain'] or false );
+
    local plain_flag = str._getBoolean( new_args['plain'] or false );
local pattern = new_args['pattern'] or '';
+
    local pattern = new_args['pattern'] or '';
local match_index = math.floor( tonumber(new_args['match']) or 1 );
+
    local match_index = math.floor( tonumber(new_args['match']) or 1 );
local nomatch = new_args['nomatch'];
+
    local nomatch = new_args['nomatch'];
 
+
   
if s == '' then
+
    if s == '' then
return str._error( 'Target string is empty' );
+
        return str._error( 'Target string is empty' );
end
+
    end
if pattern == '' then
+
    if pattern == '' then
return str._error( 'Pattern string is empty' );
+
        return str._error( 'Pattern string is empty' );
end
+
    end
if math.abs(start) < 1 or math.abs(start) > mw.ustring.len( s ) then
+
    if math.abs(start) < 1 or math.abs(start) > mw.ustring.len( s ) then
return str._error( 'Requested start is out of range' );
+
        return str._error( 'Requested start is out of range' );
end
+
    end
if match_index == 0 then
+
    if match_index == 0 then
return str._error( 'Match index is out of range' );
+
        return str._error( 'Match index is out of range' );
end
+
    end
if plain_flag then
+
    if plain_flag then
pattern = str._escapePattern( pattern );
+
        pattern = str._escapePattern( pattern );
end
+
    end
 
+
   
local result
+
    local result
if match_index == 1 then
+
    if match_index == 1 then
-- Find first match is simple case
+
        -- Find first match is simple case
result = mw.ustring.match( s, pattern, start )
+
        result = mw.ustring.match( s, pattern, start )
else
+
    else
if start > 1 then
+
        if start > 1 then
s = mw.ustring.sub( s, start );
+
            s = mw.ustring.sub( s, start );
end
+
        end
 
+
       
local iterator = mw.ustring.gmatch(s, pattern);
+
        local iterator = mw.ustring.gmatch(s, pattern);
if match_index > 0 then
+
        if match_index > 0 then
-- Forward search
+
            -- Forward search
for w in iterator do
+
            for w in iterator do
match_index = match_index - 1;
+
                match_index = match_index - 1;
if match_index == 0 then
+
                if match_index == 0 then
result = w;
+
                    result = w;
break;
+
                    break;
end
+
                end
end
+
            end  
else
+
        else
-- Reverse search
+
            -- Reverse search
local result_table = {};
+
            local result_table = {};
local count = 1;
+
            local count = 1;
for w in iterator do
+
            for w in iterator do
result_table[count] = w;
+
                result_table[count] = w;
count = count + 1;
+
                count = count + 1;
end
+
            end
 
+
           
result = result_table[ count + match_index ];
+
            result = result_table[ count + match_index ];          
end
+
        end
end
+
    end      
 
+
   
if result == nil then
+
    if result == nil then
if nomatch == nil then
+
        if nomatch == nil then
return str._error( 'Match not found' );
+
            return str._error( 'Match not found' );
else
+
        else
return nomatch;
+
            return nomatch;
end
+
        end
else
+
    else
return result;
+
        return result;
end
+
    end
 
end
 
end
  
Line 231: Line 227:
  
 
Parameters
 
Parameters
target: The string to search
+
    target: The string to search
pos: The index for the character to return
+
    pos: The index for the character to return
  
 
If invoked using named parameters, Mediawiki will automatically remove any leading or
 
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
+
trailing whitespace from the target string.  In some circumstances this is desirable, in  
 
other cases one may want to preserve the whitespace.
 
other cases one may want to preserve the whitespace.
  
 
The first character has an index value of 1.
 
The first character has an index value of 1.
  
If one requests a negative value, this function will select a character by counting backwards
+
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.
 
from the end of the string.  In other words pos = -1 is the same as asking for the last character.
  
Line 246: Line 242:
 
]]
 
]]
 
function str.pos( frame )
 
function str.pos( frame )
local new_args = str._getParameters( frame.args, {'target', 'pos'} );
+
    local new_args = str._getParameters( frame.args, {'target', 'pos'} );
local target_str = new_args['target'] or '';
+
    local target_str = new_args['target'] or '';
local pos = tonumber( new_args['pos'] ) or 0;
+
    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 );
+
    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
 
end
  
Line 261: Line 257:
  
 
This function duplicates the behavior of {{str_find}}, including all of its quirks.
 
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
+
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.
 
new code and templates.  New code is recommended to use the "find" function instead.
  
Line 272: Line 268:
 
]]
 
]]
 
function str.str_find( frame )
 
function str.str_find( frame )
local new_args = str._getParameters( frame.args, {'source', 'target'} );
+
    local new_args = str._getParameters( frame.args, {'source', 'target'} );
local source_str = new_args['source'] or '';
+
    local source_str = new_args['source'] or '';
local target_str = new_args['target'] or '';
+
    local target_str = new_args['target'] or '';
  
if target_str == '' then
+
    if target_str == '' then
return 1;
+
        return 1;
end
+
    end  
 
+
   
local start = mw.ustring.find( source_str, target_str, 1, true )
+
    local start = mw.ustring.find( source_str, target_str, 1, true )
if start == nil then
+
    if start == nil then
start = -1
+
        start = -1
end
+
    end
 
+
   
return start
+
    return start
 
end
 
end
  
Line 300: Line 296:
  
 
Parameters
 
Parameters
source: The string to search
+
    source: The string to search
target: The string or pattern to find within source
+
    target: The string or pattern to find within source
start: The index within the source string to start the search, defaults to 1
+
    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
+
    plain: Boolean flag indicating that target should be understood as plain
text and not as a Lua style regular expression, defaults to true
+
        text and not as a Lua style regular expression, defaults to true
  
 
If invoked using named parameters, Mediawiki will automatically remove any leading or
 
If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from the parameter.  In some circumstances this is desirable, in
+
trailing whitespace from the parameter.  In some circumstances this is desirable, in  
 
other cases one may want to preserve the whitespace.
 
other cases one may want to preserve the whitespace.
  
This function returns the first index >= "start" where "target" can be found
+
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
+
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 returns 0.  If either "source" or "target" are missing / empty, this
 
function also returns 0.
 
function also returns 0.
Line 318: Line 314:
 
]]
 
]]
 
function str.find( frame )
 
function str.find( frame )
local new_args = str._getParameters( frame.args, {'source', 'target', 'start', 'plain' } );
+
    local new_args = str._getParameters( frame.args, {'source', 'target', 'start', 'plain' } );  
local source_str = new_args['source'] or '';
+
    local source_str = new_args['source'] or '';
local pattern = new_args['target'] or '';
+
    local pattern = new_args['target'] or '';
local start_pos = tonumber(new_args['start']) or 1;
+
    local start_pos = tonumber(new_args['start']) or 1;
local plain = new_args['plain'] or true;
+
    local plain = new_args['plain'] or true;
 +
       
 +
    if source_str == '' or pattern == '' then
 +
        return 0;
 +
    end   
 +
   
 +
    plain = str._getBoolean( plain );
  
if source_str == '' or pattern == '' then
+
    local start = mw.ustring.find( source_str, pattern, start_pos, plain )
return 0;
+
    if start == nil then
end
+
        start = 0
 
+
    end
plain = str._getBoolean( plain );
+
   
 
+
    return start
local start = mw.ustring.find( source_str, pattern, start_pos, plain )
 
if start == nil then
 
start = 0
 
end
 
 
 
return start
 
 
end
 
end
  
Line 351: Line 347:
  
 
Parameters
 
Parameters
source: The string to search
+
    source: The string to search
pattern: The string or pattern to find within source
+
    pattern: The string or pattern to find within source
replace: The replacement text
+
    replace: The replacement text
count: The number of occurrences to replace, defaults to all.
+
    count: The number of occurences to replace, defaults to all.
plain: Boolean flag indicating that pattern should be understood as plain
+
    plain: Boolean flag indicating that pattern should be understood as plain
text and not as a Lua style regular expression, defaults to true
+
        text and not as a Lua style regular expression, defaults to true  
 
]]
 
]]
 
function str.replace( frame )
 
function str.replace( frame )
local new_args = str._getParameters( frame.args, {'source', 'pattern', 'replace', 'count', 'plain' } );
+
    local new_args = str._getParameters( frame.args, {'source', 'pattern', 'replace', 'count', 'plain' } );  
local source_str = new_args['source'] or '';
+
    local source_str = new_args['source'] or '';
local pattern = new_args['pattern'] or '';
+
    local pattern = new_args['pattern'] or '';
local replace = new_args['replace'] or '';
+
    local replace = new_args['replace'] or '';
local count = tonumber( new_args['count'] );
+
    local count = tonumber( new_args['count'] );
local plain = new_args['plain'] or true;
+
    local plain = new_args['plain'] or true;
 
+
       
if source_str == '' or pattern == '' then
+
    if source_str == '' or pattern == '' then
return source_str;
+
        return source_str;
end
+
    end  
plain = str._getBoolean( plain );
+
    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 plain then
 +
        pattern = str._escapePattern( pattern );
 +
        replace = mw.ustring.gsub( replace, "%%", "%%%%" ); --Only need to escape replacement sequences.
 +
    end
 +
   
 +
    local result;
  
if count ~= nil then
+
    if count ~= nil then
result = mw.ustring.gsub( source_str, pattern, replace, count );
+
        result = mw.ustring.gsub( source_str, pattern, replace, count );
else
+
    else
result = mw.ustring.gsub( source_str, pattern, replace );
+
        result = mw.ustring.gsub( source_str, pattern, replace );
end
+
    end      
  
return result;
+
    return result;
 
end
 
end
  
--[[
+
--[[  
simple function to pipe string.rep to templates.
+
    simple function to pipe string.rep to templates.
 
]]
 
]]
  
 
function str.rep( frame )
 
function str.rep( frame )
local repetitions = tonumber( frame.args[2] )
+
    local repetitions = tonumber( frame.args[2] )
if not repetitions then
+
    if not repetitions then  
return str._error( 'function rep expects a number as second parameter, received "' .. ( frame.args[2] or '' ) .. '"' )
+
        return str._error( 'function rep expects a number as second parameter, received "' .. ( frame.args[2] or '' ) .. '"' )
end
+
    end
return string.rep( frame.args[1] or '', repetitions )
+
    return string.rep( frame.args[1] or '', repetitions )
end
 
 
 
--[[
 
split
 
 
 
This function splits a string by a delimiter or pattern into a new table of results.
 
 
 
Usage:
 
{{#invoke:String|split|source_str|delimiter|start_index|plain_flag}}
 
OR
 
{{#invoke:String|split|source=source_str|delimiter=delimiter|start=start_index|plain=plain_flag}}
 
 
 
Parameters
 
source: The string to split; required
 
delimiter: The string or pattern to find within source; required
 
start: The index within the source string to start the search, defaults to 1; optional
 
plain: Boolean flag indicating that delimiter should be understood as plain
 
text and not as a Lua style regular expression, defaults to true; optional
 
 
 
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 a new table of substrings of the source, split by the "delimiter".
 
Indices are 1-based.
 
If either "source" or "delimiter" are missing / empty, this function also returns nil.
 
 
 
This function should be safe for UTF-8 strings.
 
]]
 
function str.split(frame)
 
local new_args = str._getParameters(frame.args, {'source', 'delimiter', 'start', 'plain'});
 
local source_str = new_args['source'] or '';
 
local pattern = new_args['delimiter'] or '';
 
if source_str=='' or pattern=='' then return nil; end -- required fields
 
local start_pos = tonumber(new_args['start']) or 1; -- optionals
 
local plain str._getBoolean(new_args['plain'] or true);
 
return mw.ustring.split(source_str, pattern, start_pos, plain); -- table
 
 
end
 
end
 
function str.count(frame)
 
local new_args = str._getParameters( frame.args, {'source', 'substr'} );
 
local source_str = new_args['source'] or '';
 
local substr = new_args['substr'] or '';
 
 
if source_str == '' or pattern == '' then return nil; end
 
local dispose, count = string.gsub(source_str, substr, "")
 
 
return count
 
end
 
 
  
 
--[[
 
--[[
Line 455: Line 402:
 
]]
 
]]
 
function str._getParameters( frame_args, arg_list )
 
function str._getParameters( frame_args, arg_list )
local new_args = {};
+
    local new_args = {};
local index = 1;
+
    local index = 1;
local value;
+
    local value;
 
+
   
for i,arg in ipairs( arg_list ) do
+
    for i,arg in ipairs( arg_list ) do
value = frame_args[arg]
+
        value = frame_args[arg]
if value == nil then
+
        if value == nil then
value = frame_args[index];
+
            value = frame_args[index];
index = index + 1;
+
            index = index + 1;
end
+
        end
new_args[arg] = value;
+
        new_args[arg] = value;
end
+
    end
 
+
   
return new_args;
+
    return new_args;
end
+
end      
  
 
--[[
 
--[[
Line 475: Line 422:
 
]]
 
]]
 
function str._error( error_str )
 
function str._error( error_str )
local frame = mw.getCurrentFrame();
+
    local frame = mw.getCurrentFrame();
local error_category = frame.args.error_category or 'Errors reported by Module String';
+
    local error_category = frame.args.error_category or 'Errors reported by Module String';
local ignore_errors = frame.args.ignore_errors or false;
+
    local ignore_errors = frame.args.ignore_errors or false;
local no_category = frame.args.no_category or false;
+
    local no_category = frame.args.no_category or false;
 
+
   
if str._getBoolean(ignore_errors) then
+
    if str._getBoolean(ignore_errors) then
return '';
+
        return '';
end
+
    end
 
+
   
local error_str = '<strong class="error">String Module Error: ' .. error_str .. '</strong>';
+
    local error_str = '<strong class="error">String Module Error: ' .. error_str .. '</strong>';
if error_category ~= '' and not str._getBoolean( no_category ) then
+
    if error_category ~= '' and not str._getBoolean( no_category ) then
error_str = '[[Category:' .. error_category .. ']]' .. error_str;
+
        error_str = '[[Category:' .. error_category .. ']]' .. error_str;
end
+
    end      
 
+
   
return error_str;
+
    return error_str;
 
end
 
end
  
Line 496: Line 443:
 
]]
 
]]
 
function str._getBoolean( boolean_str )
 
function str._getBoolean( boolean_str )
local boolean_value;
+
    local boolean_value;
 
+
   
if type( boolean_str ) == 'string' then
+
    if type( boolean_str ) == 'string' then
boolean_str = boolean_str:lower();
+
        boolean_str = boolean_str:lower();
if boolean_str == 'false' or boolean_str == 'no' or boolean_str == '0'
+
        if boolean_str == 'false' or boolean_str == 'no' or boolean_str == '0'  
or boolean_str == '' then
+
                or boolean_str == '' then
boolean_value = false;
+
            boolean_value = false;
else
+
        else
boolean_value = true;
+
            boolean_value = true;
end
+
        end  
elseif type( boolean_str ) == 'boolean' then
+
    elseif type( boolean_str ) == 'boolean' then
boolean_value = boolean_str;
+
        boolean_value = boolean_str;
else
+
    else
error( 'No boolean value found' );
+
        error( 'No boolean value found' );
end
+
    end  
return boolean_value
+
    return boolean_value
 
end
 
end
  
 
--[[
 
--[[
Helper function that escapes all pattern characters so that they will be treated
+
Helper function that escapes all pattern characters so that they will be treated  
 
as plain text.
 
as plain text.
 
]]
 
]]
 
function str._escapePattern( pattern_str )
 
function str._escapePattern( pattern_str )
return mw.ustring.gsub( pattern_str, "([%(%)%.%%%+%-%*%?%[%^%$%]])", "%%%1" );
+
    return mw.ustring.gsub( pattern_str, "([%(%)%.%%%+%-%*%?%[%^%$%]])", "%%%1" );
 
end
 
end
  
 
return str
 
return str

Revision as of 18:40, 13 December 2018

Documentation for this module may be created at Module:String/sandbox/doc

--[[  

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.
]]

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 fist 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

--[[
This function implements that features of {{str sub old}} and is kept in order
to maintain these older templates.
]]
function str.sublength( frame )
    local i = tonumber( frame.args.i ) or 0
    local len = tonumber( frame.args.len )
    return mw.ustring.sub( frame.args.s, i + 1, len and ( i + len ) )
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|pos|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

]]
function str.match( frame )
    local new_args = str._getParameters( frame.args, {'s', 'pattern', 'start', 'match', 'plain', 'nomatch'} );
    local s = new_args['s'] or '';
    local start = tonumber( new_args['start'] ) or 1;
    local plain_flag = str._getBoolean( new_args['plain'] or false );
    local pattern = new_args['pattern'] or '';
    local match_index = math.floor( tonumber(new_args['match']) or 1 );
    local nomatch = new_args['nomatch'];
    
    if s == '' then
        return str._error( 'Target string is empty' );
    end
    if pattern == '' then
        return str._error( 'Pattern string is empty' );
    end
    if math.abs(start) < 1 or math.abs(start) > mw.ustring.len( s ) then
        return str._error( 'Requested start is out of range' );
    end
    if match_index == 0 then
        return str._error( 'Match index is out of range' );
    end
    if plain_flag then
        pattern = str._escapePattern( pattern );
    end
    
    local result
    if match_index == 1 then
        -- Find first match is simple case
        result = mw.ustring.match( s, pattern, start )
    else
        if start > 1 then
            s = mw.ustring.sub( s, start );
        end
        
        local iterator = mw.ustring.gmatch(s, pattern);
        if match_index > 0 then
            -- Forward search
            for w in iterator do
                match_index = match_index - 1;
                if match_index == 0 then
                    result = w;
                    break;
                end
            end    
        else
            -- Reverse search
            local result_table = {};
            local count = 1;
            for w in iterator do
                result_table[count] = w;
                count = count + 1;
            end
            
            result = result_table[ count + match_index ];            
        end
    end        
    
    if result == nil then
        if nomatch == nil then
            return str._error( 'Match not found' );
        else
            return nomatch;
        end
    else
        return result;
    end
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

--[[
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.
]]
function str.str_find( frame )
    local new_args = str._getParameters( frame.args, {'source', 'target'} );
    local source_str = new_args['source'] or '';
    local target_str = new_args['target'] or '';

    if target_str == '' then
        return 1;
    end    
    
    local start = mw.ustring.find( source_str, target_str, 1, true )
    if start == nil then
        start = -1
    end
    
    return start
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

--[[ 
    simple function to pipe string.rep to templates.
]]

function str.rep( frame )
    local repetitions = tonumber( frame.args[2] )
    if not repetitions then 
        return str._error( 'function rep expects a number as second parameter, received "' .. ( frame.args[2] or '' ) .. '"' )
    end
    return string.rep( frame.args[1] or '', repetitions )
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 i,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