Module:String: Difference between revisions
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use tabs instead of spaces, and remove trailing whitespace
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m (use tabs instead of spaces, and remove trailing whitespace) |
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--[[ | --[[ | ||
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. | ||
]] | ]] | ||
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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 s = new_args['s'] or ''; | |||
return mw.ustring.len( s ) | |||
end | end | ||
Line 61: | Line 61: | ||
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 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 | end | ||
Line 101: | Line 101: | ||
]] | ]] | ||
function str.sublength( frame ) | 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 | end | ||
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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. | ||
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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. | ||
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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 149: | Line 149: | ||
]] | ]] | ||
function str.match( frame ) | 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 | end | ||
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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 242: | Line 242: | ||
]] | ]] | ||
function str.pos( frame ) | 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 | end | ||
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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 268: | Line 268: | ||
]] | ]] | ||
function str.str_find( frame ) | 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 | end | ||
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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 314: | Line 314: | ||
]] | ]] | ||
function str.find( frame ) | 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 | end | ||
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count: The number of occurences 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 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 | 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] ) | |||
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 | end | ||
Line 410: | Line 410: | ||
]] | ]] | ||
function str.escapePattern( frame ) | function str.escapePattern( frame ) | ||
local pattern_str = frame.args[1] | |||
if not pattern_str then | |||
return str._error( 'No pattern string specified' ); | |||
end | |||
local result = str._escapePattern( pattern_str ) | |||
return result | |||
end | end | ||
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]] | ]] | ||
function str._getParameters( frame_args, arg_list ) | 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 | end | ||
--[[ | --[[ | ||
Line 445: | Line 445: | ||
]] | ]] | ||
function str._error( error_str ) | 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 | end | ||
Line 466: | Line 466: | ||
]] | ]] | ||
function str._getBoolean( boolean_str ) | 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 | 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" ); | |||
end | end | ||
return str | return str |