Difference between revisions of "Module:String/sandbox"

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blackwiki>Lemondoge
blackwiki>Dinoguy1000
(fix comment; trim trailing whitespace; spaces --> tabs)
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 40: Line 40:
  
 
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 '' or 'string' or 'string_to_detect_length_of';
    return mw.ustring.len( s )
+
return mw.ustring.len( s )
 
end
 
end
  
Line 62: Line 62:
  
 
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
 +
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
  
    -- Convert negatives for range checking
+
return mw.ustring.sub( s, i, j )
    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
 
end
  
Line 105: Line 105:
 
]]
 
]]
 
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 113:
 
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 119:
 
{{#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|pos|s=source_string|pattern=pattern_string|start=start_index
+
{{#invoke:String|match|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 153:
 
]]
 
]]
 
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 231:
  
 
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 246:
 
]]
 
]]
 
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
  
    if pos == 0 or math.abs(pos) > mw.ustring.len( target_str ) then
+
return mw.ustring.sub( target_str, pos, pos );
        return str._error( 'String index out of range' );
 
    end   
 
   
 
    return mw.ustring.sub( target_str, pos, pos );
 
 
end
 
end
  
Line 261: Line 261:
  
 
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 272:
 
]]
 
]]
 
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
 +
return 1;
 +
end
 +
 
 +
local start = mw.ustring.find( source_str, target_str, 1, true )
 +
if start == nil then
 +
start = -1
 +
end
  
    if target_str == '' then
+
return start
        return 1;
 
    end   
 
   
 
    local start = mw.ustring.find( source_str, target_str, 1, true )
 
    if start == nil then
 
        start = -1
 
    end
 
   
 
    return start
 
 
end
 
end
  
Line 300: Line 300:
  
 
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 318:
 
]]
 
]]
 
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
+
if source_str == '' or pattern == '' then
        return 0;
+
return 0;
    end  
+
end
   
+
 
    plain = str._getBoolean( plain );
+
plain = str._getBoolean( plain );
 +
 
 +
local start = mw.ustring.find( source_str, pattern, start_pos, plain )
 +
if start == nil then
 +
start = 0
 +
end
  
    local start = mw.ustring.find( source_str, pattern, start_pos, plain )
+
return start
    if start == nil then
 
        start = 0
 
    end
 
   
 
    return start
 
 
end
 
end
  
Line 351: Line 351:
  
 
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 occurrences 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
  
    if plain then
+
local result;
        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
 
end
  
Line 410: Line 410:
  
 
Parameters
 
Parameters
    source: The string to split; required
+
source: The string to split; required
    delimiter: The string or pattern to find within source; 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
+
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
+
plain: Boolean flag indicating that delimiter should be understood as plain
        text and not as a Lua style regular expression, defaults to true; optional
+
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
 
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.
  
Line 427: Line 427:
 
]]
 
]]
 
function str.split(frame)
 
function str.split(frame)
    local new_args = str._getParameters(frame.args, {'source', 'delimiter', 'start', 'plain'});  
+
local new_args = str._getParameters(frame.args, {'source', 'delimiter', 'start', 'plain'});
    local source_str = new_args['source'] or '';
+
local source_str = new_args['source'] or '';
    local pattern = new_args['delimiter'] or '';
+
local pattern = new_args['delimiter'] or '';
    if source_str=='' or pattern=='' then return nil; end -- required fields
+
if source_str=='' or pattern=='' then return nil; end -- required fields
    local start_pos = tonumber(new_args['start']) or 1; -- optionals
+
local start_pos = tonumber(new_args['start']) or 1; -- optionals
    local plain str._getBoolean(new_args['plain'] or true);
+
local plain str._getBoolean(new_args['plain'] or true);
    return mw.ustring.split(source_str, pattern, start_pos, plain); -- table
+
return mw.ustring.split(source_str, pattern, start_pos, plain); -- table
 
end
 
end
  
 
function str.count(frame)
 
function str.count(frame)
 
local new_args = str._getParameters( frame.args, {'source', 'substr'} );
 
local new_args = str._getParameters( frame.args, {'source', 'substr'} );
    local source_str = new_args['source'] or '';
+
local source_str = new_args['source'] or '';
    local substr = new_args['substr'] or '';
+
local substr = new_args['substr'] or '';
   
+
 
    if source_str == '' or pattern == '' then return nil; end
+
if source_str == '' or pattern == '' then return nil; end
    local dispose, count = string.gsub(source_str, substr, "")
+
local dispose, count = string.gsub(source_str, substr, "")
   
+
 
    return count
+
return count
 
end
 
end
+
 
  
 
--[[
 
--[[
Line 455: Line 455:
 
]]
 
]]
 
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 475:
 
]]
 
]]
 
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 496:
 
]]
 
]]
 
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 19:08, 12 January 2017

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}}
OR
{{#invoke:String|len|string=target_string}}
OR
{{#invoke:String|len|string_to_detect_length_of=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 '' or 'string' or 'string_to_detect_length_of';
	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|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

]]
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 occurrences 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

--[[
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

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


--[[
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