Mô đun:String/sandbox

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Bước tới điều hướng Bước tới tìm kiếm
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