Anonymous user
Module:String: Difference between revisions
add support for finding the position of a string or pattern inside another string.
(Oh, the existing code is 0-based) |
(add support for finding the position of a string or pattern inside another string.) |
||
Line 19:
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". Both
strings have any leading or trailing whitespace removed before searching.
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 source_str = frame.args.source or '';
local target_str = frame.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.
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
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.
Both "source" and "target" will be trimmed so that any leading or trailing
whitespace is removed prior to searching. This function should be safe for
UTF-8 strings.
]====]
function str.find( frame )
local source_str = frame.args.source or '';
local pattern = frame.args.target or '';
local start_pos = tonumber(frame.args.start) or 1;
local plain = frame.args.plain or true;
if source_str == '' or pattern == '' then
return 0;
end
if type( plain ) == 'string' then
plain = plain:lower();
if plain == 'false' or plain == 'no' or plain == '0' then
plain = false;
else
plain = true;
end
end
local start = mw.ustring.find( source_str, pattern, start_pos, plain )
if start == nil then
start = 0
end
return start
end
return str
| |||