imported>Trappist the monk at 19:00, 12 November 2022

2022-11-12T19:00:56Z

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require ('strict')

--[[--------------------------< M A I N >----------------------------------------------------------------------

lua implementation of this regex:
[a-z]+(\-[a-z]+)*(_res\-[0-9a-f]{8}(\-[0-9a-f]{4}){3}\-[0-9a-f]{12})?

this function assumes that <target> is valid;

]]

local function main (target)
target = target or 'xyz-uvw-rst_res-12345678-1111-2222-3333-012345543210'; -- a test string that I think matches the regex

local part1, part2;
if target:find ('_res', 1, true) then
part1, part2 = target:match ('([^_]+)(_res.+)'); -- split at constant '_res'; part 2 nil when no constant '_res'
else
part1 = target; -- part2 not in target
end

local captures_t = {}; -- sequence to hold captures (left to right)

if part1:find ('-', 1, true) then -- if part1 has hyphens
for capture in part1:gmatch ('(%-%l+)') do
table.insert (captures_t, capture); -- add to the captures_t sequence
end
end

if part2 then
table.insert (captures_t, part2); -- the part2 capture
for capture in part2:gmatch ('%-%x%x%x%x%f[%-]') do
table.insert (captures_t, capture); -- add to the captures_t sequence
end
end

return mw.dumpObject (captures_t);
end

--[[--------------------------< I S _ V A L I D >--------------------------------------------------------------
]]

local function is_valid (target)

target = target or 'xyz-uvw-rst_res-12345678-1111-2222-3333-012345543210'; -- a test string that I think matches the regex

local part1, part2;
if target:find ('_res', 1, true) then
part1, part2 = target:match ('([^_]+)(_res.+)'); -- split at constant '_res'; part 2 nil when no constant '_res'
else
part1 = target; -- part2 not in target
end

if part1:find ('[^%-%l]') then -- if <part1> has anything but lowercase letters and hyphens
return false; -- invalid so return false
else -- here when <part1> has only lowercase letters and hyphens
if part1:match ('^%-') or part1:match ('%-$') then -- first and last characters in <part1> must be lowercase letters
return false; -- invalid so return false
end
end

if part2 then
if not part2:match ('^_res%-%x%x%x%x%x%x%x%x%-%x%x%x%x%-%x%x%x%x%-%x%x%x%x%-%x%x%x%x%x%x%x%x%x%x%x%x$') then
return false; -- invalid so return false
end
end

return true; -- valid so return true
end

--[[--------------------------< E X P O R T S >----------------------------------------------------------------
]]

return {
main = main,
is_valid = is_valid,
}

Module:Sandbox/trappist the monk/MSGJ regex - Revision history

imported>Trappist the monk at 19:00, 12 November 2022