From: Martin DeMello <martindemello@...>
Date: 2008-08-05T15:09:24+09:00
Subject: Re: Catching (or saving) errors.

On Mon, Aug 4, 2008 at 10:34 PM, Tim Mcd <tmcdowell@gmail.com> wrote:
> So, I am currently working on an Interactive Fiction like game in Ruby,
> and have stumbled across a bit of a problem. The 'move' function makes a
> call to the room's 'exits' variable (exits[:north], for instance) but I
> want it to catch if the variable :north doesn't exist to display
> something like "You can't go taht way!". I can't figure out how to do
> this with my meager skills. :(
>
> Any help would be greatly appreciated!

This should illustrate the basic approach:

exits = {:north => 'front of building', :east => 'fork in road'}
print "what now? > "
move = gets.chomp.downcase
dir = case move
			when "n", "north"
				:north
			when "s", "south"
				:south
			when "e", "east"
				:east
			when "w", "west"
				:west
			else
				nil
			end

if dir
	if exits[dir]
		puts "moving to #{exits[dir]}"
	else
		puts "you can't go that way!"
	end
else
	puts "no such direction. please enter one of [n]orth, [s]outh, [e]ast
or [w]est"
end

martin