A few questions about Lua pattern matching

Brusalk · 09-09-12, 11:46 PM

So in one of my addons I need access to information on how often a DoT/HoT ticks on a unit.

One of the ways I'm experimenting with is pulling the hasted tick time from the tooltip itself on UNIT_AURA event.

My code:

Code:

addEvent(function(self, event, unit)
	for i=1, 40 do
		for _, spellbar in ipairs(ns.spellbars.active) do
			if spellbar.spellConfig.debuff[1] > 0 then -- We have a debuff to look at
				if unit == (type(spellbar.spellConfig.debuff[2]) == "string" and spellbar.spellConfig.debuff[2] or "target") then
					local name, rank, icon, count, dispelType, duration, expires, caster, isStealable, shouldConsolidate, spellID, canApplyAura, isBossDebuff, value1, value2, value3 = UnitDebuff(unit, i)
					if caster == "player" then
						if spellbar.spellConfig.debuff[1] == spellID then -- Ooh, we found it on this spellbar.
							ns.tooltip:SetUnitDebuff(unit, i)
							local scanText = _G["EventHorizonScanTooltipTextLeft2"]:GetText()
							local tickSpeed = tonumber(string.sub(scanText, string.find(scanText, "every ")+6, string.find(scanText, " sec")-1))
								--tonumber returns nil if it can't be converted to a number
							ns:addDebuff(spellbar, duration, tickSpeed)
							
						end
					end	
				end
			end
		end
	end
end,
"UNIT_AURA")

A cursory inspection of wowhead seems to show that all DoTs/HoTs tooltips say "every x.xx sec".
I'm not versed in Lua pattern matching at all and I managed to get the x.xx information using what I have below, but on a non-matching string it returns garbage information. tonumber() luckily returns nil if the number can't be converted, but I'm sure that there's more efficient/robust ways of doing it using pattern matching.

Does anyone know of a pattern which would match only the x.xx portion of the string to make it more efficient? (Or any other changes to my above code to make it more efficient)

Thanks

-Brusalk

Code:

tonumber(string.sub(scanText, string.find(scanText, "every ")+6, string.find(scanText, " sec")-1))

Rochet2 · 09-10-12, 02:15 AM

I dont know if its more efficent, but this should work:

Code:

local str = "623 Shadow damage every 3.55 seconds every 3.5522seconds." -- Example
local time = tonumber(str:match("every ([%d.]+) sec"))
print(time, type(time)) -- time is nil in case no numbers or decimals or the every .. sec is not found. (even without the tonumber, but it will be in string form)

SDPhantom · 09-10-12, 02:50 AM

Code:

tonumber(scanText:match("every (%d+%.%d+) sec"))

tonumber() seems to be handing a nil return fine as of WoW 5.0.4. Also note this would only be able to match on an enUS client, labels would be different in other locales. For more information on patterns and also functions that use them, here's a link to the official Lua documentation on it.