Mô đun:String/sandbox
 | Đây là trang chỗ thử mô đun cho Mô đun:String (khác). Xem thêm trang con so sánh cho trường hợp kiểm thử (chạy). |
Tài liệu mô đun[tạo]--[=[
Mô đun này nhằm cung cấp các hàm chuỗi cơ bản.
Phần nhiều hàm này cho phép gọi với các tham số có tên, các tham số không có
tên, hoặc pha trộn cả hai kiểu. Nếu sử dụng các tham số có tên, MediaWiki tự
động bỏ qua khoảng cách đằng truớc và đằng sau tham số. Tùy cách sử dụng, bạn có
thể cần giữ hoặc bỏ qua khoảng cách này.
Các tùy chọn toàn cục:
ignore_errors: Nếu là 'true' hoặc 1, bất cứ trạng thái lỗi nào sẽ cho ra
chuỗi rỗng thay vì thông báo lỗi.
error_category: Nếu xuất hiện lỗi, trang được tự động xếp vào thể loại này
và thông báo lỗi sẽ được hiển thị. Thể loại mặc định là
[[Thể loại:Trang gây lỗi trong mô đun String]].
no_category: Nếu là 'true' hoặc 1, trang không được tự động xếp vào thể loại
khi xuất hiện lỗi.
Các trường hợp kiểm thử đơn vị cho mô đun này có sẵn tại [[Mô đun:String/tests]].
]=]
local str = {}
--[[
len
This function returns the length of the target string.
Usage:
{{#gọi:String|len|target_string|}}
OR
{{#gọi:String|len|s=target_string}}
OR
{{#gọi:String|len|string=target_string}}
OR
{{#gọi: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:
{{#gọi:String|sub|target_string|start_index|end_index}}
OR
{{#gọi: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( 'Chỉ số chuỗi con nằm ngoài phạm vi' );
end
if j < i then
return str._error( 'Chỉ số chuỗi con bị lộn nguợc' );
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:
{{#gọi:String|match|source_string|pattern_string|start_index|match_number|plain_flag|nomatch_output}}
OR
{{#gọi: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( 'Chuỗi đích rỗng' );
end
if pattern == '' then
return str._error( 'Chuỗi mẫu rỗng' );
end
if math.abs(start) < 1 or math.abs(start) > mw.ustring.len( s ) then
return str._error( 'Chỉ số bắt đầu nằm ngoài phạm vi' );
end
if match_index == 0 then
return str._error( 'Chỉ số trùng khớp nằm ngoài phạm vi' );
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( 'Không tìm thấy kết quả' );
else
return nomatch;
end
else
return result;
end
end
--[[
pos
This function returns a single character from the target string at position pos.
Usage:
{{#gọi:String|pos|target_string|index_value}}
OR
{{#gọi: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( 'Chỉ số chuỗi nằm ngoài phạm vi' );
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:
{{#gọi:String|find|source_str|target_string|start_index|plain_flag}}
OR
{{#gọi: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:
{{#gọi:String|replace|source_str|pattern_string|replace_string|replacement_count|plain_flag}}
OR
{{#gọi: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( 'tham số thứ 2 của hàm rep có giá trị "' .. ( frame.args[2] or '' ) .. '" thay cho số' )
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:
{{#gọi:String|split|source_str|delimiter|start_index|plain_flag}}
OR
{{#gọi: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 'Trang gây lỗi trong mô đun 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">Lỗi mô đun String: ' .. error_str .. '</strong>';
if error_category ~= '' and not str._getBoolean( no_category ) then
error_str = '[[Thể loại:' .. 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( 'Không tìm thấy giá trị luận lý' );
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