Regular Expressions

Posted by LupusFatalis on Sat 24 Apr 2010 06:51 AM — 3 posts, 15,053 views.

LupusFatalis Sat 24 Apr 2010 06:51 AM #0

Ultimately what I'm trying to do here is match a string against a list of regular expressions and have a second list of strings to substitute.

function process_name (room_name)

	-- long regular expressions [ordered]
	reName = {"^(A|An) (somewhat |very |very very |extremely )?(small |large )?cave$",
			"^(A|An) (somewhat |very |very very |extremely )?(small |large )?cavern$",
			"^(A|An) (somewhat |very |very very |extremely )?(small |large )?tunnel$"}

	-- short strings [ordered]
	sName = {"A cave",
			"A cavern",
			"A tunnel"}

	--Convert matched long regular expressions to corresponding short strings
	for i,item in ipairs(reName) do
		room_name = rex.gsub(room_name, item, sName[i])
	end

	return roon_name

I've tried a bunch of things now, and I just can't seem to get it to work properly.

Though, this seems to indicate I'm doing it correctly: http://math2.org/luasearch/rex.html#rex_gsub

Nick Gammon Australia Forum Administrator Sun 25 Apr 2010 01:33 AM #1

This seems to work OK:


function process_name (room_name)

  -- long regular expressions [ordered]
  reName = {"^(A|An) (somewhat |very |very very |extremely )?(small |large )?cave$",
      "^(A|An) (somewhat |very |very very |extremely )?(small |large )?cavern$",
      "^(A|An) (somewhat |very |very very |extremely )?(small |large )?tunnel$"}

  -- short strings [ordered]
  sName = {"A cave",
      "A cavern",
      "A tunnel"}

  -- If a match, return corresponding short strings
  for i,item in ipairs(reName) do
    if rex.new (item):match (room_name) then
       return sName [i]
    end -- if
  end  -- for

  return roon_name

end -- function

-- tests

print (process_name ("A somewhat large cave"))   --> A cave
print (process_name ("A somewhat small cavern"))  --> A cavern
print (process_name ("An extremely large tunnel"))  --> A tunnel

LupusFatalis Sun 25 Apr 2010 03:04 PM #2

Works brilliantly, thanks Nick!