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„Module:Strengur“: Munur á milli breytinga

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uppfæra, held íslenskum villumeldingum inni.
 
Lína 1:
--[[
 
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:Villur tilkynntar af skriftunni strengur].
 
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.
]]
Lína 39:
 
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
 
Lína 61:
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 )
-- 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
 
Lína 101:
]]
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
 
Lína 109:
match
 
This function returns a substring from the source string that matches a
specified pattern.
 
Lína 115:
{{#invoke:String|match|source_string|pattern_string|start_index|match_number|plain_flag|nomatch_output}}
OR
{{#invoke:String|posmatch|s=source_string|pattern=pattern_string|start=start_index
|match=match_number|plain=plain_flag|nomatch=nomatch_output}}
 
Lína 123:
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.
Lína 133:
 
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.
 
Lína 148:
 
]]
-- This sub-routine is exported for use in other modules
function str._match( s, pattern, start, match_index, plain_flag, nomatch )
if s == '' then
return str._error( 'Leitarstrengur er tómur' )
end
if pattern == '' then
return str._error( 'Pattern string is empty' )
end
start = tonumber(start) or 1
if math.abs(start) < 1 or math.abs(start) > mw.ustring.len( s ) then
return str._error( 'Umbeðin byrjun er utan dreifisviðs' )
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
-- This is the entry point for #invoke:String|match
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'];
 
return str._match( s, pattern, start, match_index, plain_flag, nomatch )
if s == '' then
return str._error( 'Leitarstrengur er tómur' );
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( 'Umbeðin byrjun er utan dreifisviðs' );
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( 'Samsvörun fannst ekki' );
else
return nomatch;
end
else
return result;
end
end
 
Lína 231 ⟶ 237:
 
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.
 
Lína 242 ⟶ 248:
]]
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( 'Atriðaskrá strengs er utan dreifisviðs' );
end
 
return mw.ustring.sub( target_str, pos, pos );
end
 
Lína 257 ⟶ 263:
 
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.
 
Lína 268 ⟶ 274:
]]
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
 
Lína 303 ⟶ 309:
 
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.
Lína 314 ⟶ 320:
]]
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 );
 
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
 
Lína 352 ⟶ 358:
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 source_str == '' ifor pattern == plain'' then
return source_str
pattern = str._escapePattern( pattern );
end
replace = mw.ustring.gsub( replace, "%%", "%%%%" ); --Only need to escape replacement sequences.
plain = str._getBoolean( plain )
end
local result;
 
if count ~= nilplain then
pattern = str._escapePattern( pattern )
result = mw.ustring.gsub( source_str, pattern, replace, count );
replace = mw.ustring.gsub( replace, "%%", "%%%%" ) --Only need to escape replacement sequences.
else
end
result = mw.ustring.gsub( source_str, pattern, replace );
end
 
return 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( 'fallið rep bjóst við tölu sem seinna gildi, en fékk "' .. ( frame.args[2] or '' ) .. '"' )
end
return string.rep( frame.args[1] or '', repetitions )
end
 
--[[
escapePattern
 
This function escapes special characters from a Lua string pattern. See [1]
for details on how patterns work.
 
[1] https://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#Patterns
 
Usage:
{{#invoke:String|escapePattern|pattern_string}}
 
Parameters
pattern_string: The pattern string to escape.
]]
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
 
--[[
count
This function counts the number of occurrences of one string in another.
]]
function str.count(frame)
local args = str._getParameters(frame.args, {'source', 'pattern', 'plain'})
local source = args.source or ''
local pattern = args.pattern or ''
local plain = str._getBoolean(args.plain or true)
if plain then
pattern = str._escapePattern(pattern)
end
local _, count = mw.ustring.gsub(source, pattern, '')
return count
end
 
--[[
endswith
This function determines whether a string ends with another string.
]]
function str.endswith(frame)
local args = str._getParameters(frame.args, {'source', 'pattern'})
local source = args.source or ''
local pattern = args.pattern or ''
if pattern == '' then
-- All strings end with the empty string.
return "yes"
end
if mw.ustring.sub(source, -mw.ustring.len(pattern), -1) == pattern then
return "yes"
else
return ""
end
end
 
--[[
join
 
Join all non empty arguments together; the first argument is the separator.
Usage:
{{#invoke:String|join|sep|one|two|three}}
]]
function str.join(frame)
local args = {}
local sep
for _, v in ipairs( frame.args ) do
if sep then
if v ~= '' then
table.insert(args, v)
end
else
sep = v
end
end
return table.concat( args, sep or '' )
end
 
Lína 402 ⟶ 487:
]]
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
 
--[[
Lína 422 ⟶ 507:
]]
function str._error( error_str )
local frame = mw.getCurrentFrame();
local error_category = frame.args.error_category or 'Villur tilkynntar af skriftunni strengur';
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">Villa í skriftunni strengur: ' .. error_str .. '</strong>';
if error_category ~= '' and not str._getBoolean( no_category ) then
error_str = '[[Category:' .. error_category .. ']]' .. error_str;
end
end
 
return error_str;
end
 
Lína 443 ⟶ 528:
]]
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
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
 
Sótt frá „https://is.wikipedia.org/wiki/Module:Strengur“