xK/plugins/degesch/prime.lua

69 lines
2.4 KiB
Lua

--
-- prime.lua: highlight prime numbers in messages
--
-- Copyright (c) 2020, Přemysl Eric Janouch <p@janouch.name>
--
-- Permission to use, copy, modify, and/or distribute this software for any
-- purpose with or without fee is hereby granted.
--
-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
-- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
-- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
--
local smallest, highlight = 0, "\x1f"
degesch.setup_config {
smallest = {
type = "integer",
default = "0",
comment = "smallest number to scan for primality",
on_change = function (v) smallest = math.max (v, 2) end
},
highlight = {
type = "string",
default = "\"\\x1f\"",
comment = "the attribute to use for highlights",
on_change = function (v) highlight = v end
},
}
-- The prime test is actually very fast, so there is no DoS concern
local do_intercolour = function (text)
return tostring (text:gsub ("%f[%w_]%d+", function (n)
if tonumber (n) < smallest then return nil end
for i = 2, n ^ (1 / 2) do if (n % i) == 0 then return nil end end
return highlight .. n .. highlight
end))
end
local do_interlink = function (text)
local rebuilt, last = {""}, 1
for start in text:gmatch ('()\x03') do
table.insert (rebuilt, do_intercolour (text:sub (last, start - 1)))
local sub = text:sub (start + 1)
last = start + (sub:match ('^%d%d?,%d%d?()') or sub:match ('^%d?%d?()'))
table.insert (rebuilt, text:sub (start, last - 1))
end
return table.concat (rebuilt) .. do_intercolour (text:sub (last))
end
local do_message = function (text)
local rebuilt, last = {""}, 1
for run, link, endpos in text:gmatch ('(.-)(%f[%g]https?://%g+)()') do
last = endpos
table.insert (rebuilt, do_interlink (run) .. link)
end
return table.concat (rebuilt) .. do_interlink (text:sub (last))
end
-- XXX: sadly it won't typically highlight primes in our own messages,
-- unless IRCv3 echo-message is on
degesch.hook_irc (function (hook, server, line)
local start, message = line:match ("^(.- PRIVMSG .- :)(.*)$")
return message and start .. do_message (message) or line
end)