Catching (or saving) errors

ruby-talk
1

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. :frowning:

Any help would be greatly appreciated!

路路路

--
Posted via http://www.ruby-forum.com/.

2

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
聽聽聽聽聽聽when "n", "north"
聽聽聽聽聽聽聽聽:north
聽聽聽聽聽聽when "s", "south"
聽聽聽聽聽聽聽聽:south
聽聽聽聽聽聽when "e", "east"
聽聽聽聽聽聽聽聽:east
聽聽聽聽聽聽when "w", "west"
聽聽聽聽聽聽聽聽:west
聽聽聽聽聽聽else
聽聽聽聽聽聽聽聽nil
聽聽聽聽聽聽end

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

martin

路路路

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. :frowning:

Any help would be greatly appreciated!

3

Didn't know a nice if like that would just take care of it! Also, did
you test that code? Or the concept? I'm pretty sure you can't do
exits[avar[. I did some testing with that earlier...

路路路

--
Posted via http://www.ruby-forum.com/.

4

Yep, I tested it before pasting it in. What I'm doing is this:

1. defining exits as a hash
2. writing a case statement to convert move from "N" or "n" or "north"
or "NORTH" to :north
3. using the converted move as a key to look up the exits hash

In the context of a larger game, you'd have a $rooms hash, with unique
identifiers like "front of building" as location keys. So you'd say

if dir
聽聽if exits[dir]
聽聽聽聽player.move_to(exits[dir])
聽聽end
end

where player.move_to(location) would be defined something like

def move_to(location)
聽聽loc = $rooms[location]
聽聽if loc
聽聽聽聽self.current_location = loc
聽聽end
end

martin

路路路

On Tue, Aug 5, 2008 at 7:28 AM, Tim Mcd <tmcdowell@gmail.com> wrote:

Didn't know a nice if like that would just take care of it! Also, did
you test that code? Or the concept? I'm pretty sure you can't do
exits[avar[. I did some testing with that earlier...

5

Thanks a ton! You've helped out a lot! Oh, and btw, I still think the
whole obj_sword.strike(:martin) bit is hilarious :stuck_out_tongue:

路路路

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Posted via http://www.ruby-forum.com/.