diff --git a/src/__pycache__/interpreter.cpython-34.pyc b/src/__pycache__/interpreter.cpython-34.pyc
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diff --git a/src/__pycache__/interpreter.cpython-34.pyc b/src/__pycache__/interpreter.cpython-34.pyc
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diff --git a/src/__pycache__/server.cpython-34.pyc b/src/__pycache__/server.cpython-34.pyc
index 87708fb..e273538 100644
--- a/src/__pycache__/server.cpython-34.pyc
+++ b/src/__pycache__/server.cpython-34.pyc
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diff --git a/src/__pycache__/interpreter.cpython-34.pyc b/src/__pycache__/interpreter.cpython-34.pyc
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diff --git a/src/__pycache__/server.cpython-34.pyc b/src/__pycache__/server.cpython-34.pyc
index 87708fb..e273538 100644
--- a/src/__pycache__/server.cpython-34.pyc
+++ b/src/__pycache__/server.cpython-34.pyc
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diff --git a/src/__pycache__/world.cpython-34.pyc b/src/__pycache__/world.cpython-34.pyc
index f29617b..9f6b508 100644
--- a/src/__pycache__/world.cpython-34.pyc
+++ b/src/__pycache__/world.cpython-34.pyc
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diff --git a/src/__pycache__/interpreter.cpython-34.pyc b/src/__pycache__/interpreter.cpython-34.pyc
new file mode 100644
index 0000000..56c3add
--- /dev/null
+++ b/src/__pycache__/interpreter.cpython-34.pyc
Binary files differ
diff --git a/src/__pycache__/server.cpython-34.pyc b/src/__pycache__/server.cpython-34.pyc
index 87708fb..e273538 100644
--- a/src/__pycache__/server.cpython-34.pyc
+++ b/src/__pycache__/server.cpython-34.pyc
Binary files differ
diff --git a/src/__pycache__/world.cpython-34.pyc b/src/__pycache__/world.cpython-34.pyc
index f29617b..9f6b508 100644
--- a/src/__pycache__/world.cpython-34.pyc
+++ b/src/__pycache__/world.cpython-34.pyc
Binary files differ
diff --git a/src/atlantis.py b/src/atlantis.py
index ebbb075..2999593 100644
--- a/src/atlantis.py
+++ b/src/atlantis.py
@@ -7,7 +7,7 @@
 # date: 02/05/2015
 #
 
-VERSION = (0, 0, 3) #release, major revision, minor (git) revision
+VERSION = (0, 0, 5) #release, major revision, minor (git) revision
 
 import sys
 import os
@@ -48,7 +48,7 @@
 #TODO!
 def act_on_choice(choice):
     if choice == "s" or choice == "S":
-        print("What port do you want to start the server on?") #indicate range!
+        print("What port do you want to start the server on?") #TODO indicate range!
         server_port = input(">> ")
         print("What world file do you want to load?")
         print("(Specify an absolute or relative path)")
@@ -72,7 +72,7 @@
     else:
         print("Invalid choice!")
         input("Please press ENTER")
-        startMenu()
+        start_menu()
 
 
 def print_version():
@@ -99,9 +99,9 @@
     if "--version" in sys.argv or "-v" in sys.argv: print_version()
     elif "--help" in sys.argv or "-h" in sys.argv: print_help()
     elif "--server" in sys.argv and "--world" in sys.argv:
-        server_port = sys.argv[sys.argv.find("--server")+1]
+        server_port = sys.argv[sys.argv.index("--server")+1]
         world_file = sys.argv[sys.argv.index("--world")+1]
-        Server(port, world_file)
+        Server(server_port, world_file)
     elif "--client" in sys.argv:
         server_address = sys.argv[sys.argv.index("--client")+1]
         server_ip = server_address[:server_address.find(":")]

diff --git a/src/__pycache__/interpreter.cpython-34.pyc b/src/__pycache__/interpreter.cpython-34.pyc
new file mode 100644
index 0000000..56c3add
--- /dev/null
+++ b/src/__pycache__/interpreter.cpython-34.pyc
Binary files differ
diff --git a/src/__pycache__/server.cpython-34.pyc b/src/__pycache__/server.cpython-34.pyc
index 87708fb..e273538 100644
--- a/src/__pycache__/server.cpython-34.pyc
+++ b/src/__pycache__/server.cpython-34.pyc
Binary files differ
diff --git a/src/__pycache__/world.cpython-34.pyc b/src/__pycache__/world.cpython-34.pyc
index f29617b..9f6b508 100644
--- a/src/__pycache__/world.cpython-34.pyc
+++ b/src/__pycache__/world.cpython-34.pyc
Binary files differ
diff --git a/src/atlantis.py b/src/atlantis.py
index ebbb075..2999593 100644
--- a/src/atlantis.py
+++ b/src/atlantis.py
@@ -7,7 +7,7 @@
 # date: 02/05/2015
 #
 
-VERSION = (0, 0, 3) #release, major revision, minor (git) revision
+VERSION = (0, 0, 5) #release, major revision, minor (git) revision
 
 import sys
 import os
@@ -48,7 +48,7 @@
 #TODO!
 def act_on_choice(choice):
     if choice == "s" or choice == "S":
-        print("What port do you want to start the server on?") #indicate range!
+        print("What port do you want to start the server on?") #TODO indicate range!
         server_port = input(">> ")
         print("What world file do you want to load?")
         print("(Specify an absolute or relative path)")
@@ -72,7 +72,7 @@
     else:
         print("Invalid choice!")
         input("Please press ENTER")
-        startMenu()
+        start_menu()
 
 
 def print_version():
@@ -99,9 +99,9 @@
     if "--version" in sys.argv or "-v" in sys.argv: print_version()
     elif "--help" in sys.argv or "-h" in sys.argv: print_help()
     elif "--server" in sys.argv and "--world" in sys.argv:
-        server_port = sys.argv[sys.argv.find("--server")+1]
+        server_port = sys.argv[sys.argv.index("--server")+1]
         world_file = sys.argv[sys.argv.index("--world")+1]
-        Server(port, world_file)
+        Server(server_port, world_file)
     elif "--client" in sys.argv:
         server_address = sys.argv[sys.argv.index("--client")+1]
         server_ip = server_address[:server_address.find(":")]
diff --git a/src/interpreter.py b/src/interpreter.py
index 86cd37e..6db846e 100644
--- a/src/interpreter.py
+++ b/src/interpreter.py
@@ -12,67 +12,134 @@
 from world import World
 
 
-#
-# FIXME: conceptually a bit messed up, especially needs work on how the argument
-# gets passed to the OptionCommand
-#
-
-
-class OptionCommand(object):
-    '''
-    This is the super class for all option commands. (A define command
-    includes one or more option commands.)
-    '''
-
-    def __init__(self, name, doc_string, arg):
-        self.name = name
-        self.doc_string = doc_string
-        self.arg = arg
-
-    def act(self):
-        '''
-        Carry out this option commands action with argument arg.
-        Has to be extended by subclasses!
-        '''
-        raise NotImplementedError
-
-
 class DefineCommand(object):
     '''
     This is the super class for all define commands. It should be extended
     for each individual command, like define-place, define-monster, etc.
+
+    Each define command works by creating the relevant object, then fleshing
+    it out as more options are passed to it. Finally, the finished object is
+    returned.
     '''
 
     def __init__(self, name, doc_string):
         self.name = name
         self.doc_string = doc_string
-        self.option_registry = []
+        self.option_registry = dict()
 
-    def add_option(self, option_command):
-        self.option_registry.append(option_command)
-
-    def execute(self):
+    def init_object(self, object_name):
         '''
-        Execute this command with all its options
+        Initialize the object this command creates
         '''
-        for o in self.option_registry:
-            o.act(arg)
+        raise NotImplementedError
+
+    def return_object(self):
+        '''
+        Return the type of the game object ('place', 'npc', 'item' or
+        'monster') and the object itself
+        '''
+        raise NotImplementedError
+
+    def pass_option(self, option_name, option_argument):
+        '''
+        Pass this define command one of its options and the relevant argument
+        '''
+        self.option_registry[option_name]["function"](option_argument)
+
+    def add_option(self, option_name, option_docstring, option_function):
+        '''
+        Add an option for this define command. Arguments:
+        option_name: The name of this option as it would appear in
+                     an atl source file
+        option_docstring: A description of this option
+        option_function: The function that this option calls
+                     (this function should take exactly one string argument)
+        '''
+        option_dict = dict["docstring":option_docstring,
+                           "function":option_function]
+        self.option_registry[option_name] = option_dict
 
 
-define_command_registry = []
+define_command_registry = dict()
 
 def register_define_command(def_com):
-    define_command_registry.append(def_com)
+    define_command_registry[def_com.name] = def_com
 
 
 class Parser(object):
     '''
     The actual parser class. It reads in a world file and transforms it into
-    a series of DefineCommands.
+    a series of DefineCommands, which are then executed
     '''
 
-    def __init__(self, world_file):
-        self.world_file = world_file
+    def __init__(self, world_file_name):
+        self.line_command_registry = dict()
+        self.world = World()
+        self.add_line_commands()
+        self.load(world_file_name)
+        return self.world
 
-    def generate_world(self):
-        return World()
+    def load(self, world_file_name):
+        '''
+        Load a world file and pass it on to the interpreter
+        '''
+        try:
+            world_file = open(world_file_name, 'r')
+            atl_text = world_file.readlines()
+            world_file.close()
+        except IOError:
+            print("Failed to load world file '"+world_file_name+"'!")
+        self.interpret_atl(atl_text)
+
+    def add_line_commands(self):
+        '''
+        Line commands are ATL constructs that only take up one line
+        (unlike define commands). All line commands must be registered in
+        this method by adding them to the line_command_registry and setting
+        their key-value to the method to be called when their key appears
+        in an ATL source file.
+        '''
+        self.line_command_registry["load"] = self.load
+        self.line_command_registry["start-place"] = self.world.set_starting_place
+
+    def interpret_atl(self, atl_source):
+        '''
+        This method interprets a list of atl source lines, passing them
+        on to the relevant define commands.
+        '''
+        define_command = None # The define command currently being executed
+        line_no = 0
+        for line in atl_source:
+            # TODO allow for linebreaks
+            line_no = line_no + 1
+            if line[0] == "#":
+                pass #comments are ignored
+            elif (line == "" or line == "\n") and define_command:
+                # Empty lines finish off define blocks
+                object_type, game_object = define_command.return_object()
+                self.world.add_object(object_type, game_object)
+                define_command = None
+            else:
+                print("Line: '"+line+"'")
+                command = line.split()[0]
+                # execute a line command
+                if command in line_command_registry.keys():
+                    line_command_registry[command](line[line.find(" ")+1:])
+                # start of a define block
+                elif command in define_command_registry.keys():
+                    define_command = define_command_registry[command]
+                    object_name = line[line.find(" ")+1:]
+                    define_command.init_object(object_name)
+                # parse an option command
+                elif line[0] == " " or line[0] == "\t":
+                    while line[0] == " " or line[0] == "\t":
+                        line = line[1:]
+                    if line and define_command:
+                        option_command = line.split()[0]
+                        option_arg = line[line.find(" ")+1:]
+                        define_command.pass_option(option_command, option_arg)
+                    else:
+                        # XXX: What should be done here? Do nothing, raise a
+                        # syntax error, or something else?
+                        print("Unrecognized syntax in line "+str(line_no)+"!")
+

diff --git a/src/__pycache__/interpreter.cpython-34.pyc b/src/__pycache__/interpreter.cpython-34.pyc
new file mode 100644
index 0000000..56c3add
--- /dev/null
+++ b/src/__pycache__/interpreter.cpython-34.pyc
Binary files differ
diff --git a/src/__pycache__/server.cpython-34.pyc b/src/__pycache__/server.cpython-34.pyc
index 87708fb..e273538 100644
--- a/src/__pycache__/server.cpython-34.pyc
+++ b/src/__pycache__/server.cpython-34.pyc
Binary files differ
diff --git a/src/__pycache__/world.cpython-34.pyc b/src/__pycache__/world.cpython-34.pyc
index f29617b..9f6b508 100644
--- a/src/__pycache__/world.cpython-34.pyc
+++ b/src/__pycache__/world.cpython-34.pyc
Binary files differ
diff --git a/src/atlantis.py b/src/atlantis.py
index ebbb075..2999593 100644
--- a/src/atlantis.py
+++ b/src/atlantis.py
@@ -7,7 +7,7 @@
 # date: 02/05/2015
 #
 
-VERSION = (0, 0, 3) #release, major revision, minor (git) revision
+VERSION = (0, 0, 5) #release, major revision, minor (git) revision
 
 import sys
 import os
@@ -48,7 +48,7 @@
 #TODO!
 def act_on_choice(choice):
     if choice == "s" or choice == "S":
-        print("What port do you want to start the server on?") #indicate range!
+        print("What port do you want to start the server on?") #TODO indicate range!
         server_port = input(">> ")
         print("What world file do you want to load?")
         print("(Specify an absolute or relative path)")
@@ -72,7 +72,7 @@
     else:
         print("Invalid choice!")
         input("Please press ENTER")
-        startMenu()
+        start_menu()
 
 
 def print_version():
@@ -99,9 +99,9 @@
     if "--version" in sys.argv or "-v" in sys.argv: print_version()
     elif "--help" in sys.argv or "-h" in sys.argv: print_help()
     elif "--server" in sys.argv and "--world" in sys.argv:
-        server_port = sys.argv[sys.argv.find("--server")+1]
+        server_port = sys.argv[sys.argv.index("--server")+1]
         world_file = sys.argv[sys.argv.index("--world")+1]
-        Server(port, world_file)
+        Server(server_port, world_file)
     elif "--client" in sys.argv:
         server_address = sys.argv[sys.argv.index("--client")+1]
         server_ip = server_address[:server_address.find(":")]
diff --git a/src/interpreter.py b/src/interpreter.py
index 86cd37e..6db846e 100644
--- a/src/interpreter.py
+++ b/src/interpreter.py
@@ -12,67 +12,134 @@
 from world import World
 
 
-#
-# FIXME: conceptually a bit messed up, especially needs work on how the argument
-# gets passed to the OptionCommand
-#
-
-
-class OptionCommand(object):
-    '''
-    This is the super class for all option commands. (A define command
-    includes one or more option commands.)
-    '''
-
-    def __init__(self, name, doc_string, arg):
-        self.name = name
-        self.doc_string = doc_string
-        self.arg = arg
-
-    def act(self):
-        '''
-        Carry out this option commands action with argument arg.
-        Has to be extended by subclasses!
-        '''
-        raise NotImplementedError
-
-
 class DefineCommand(object):
     '''
     This is the super class for all define commands. It should be extended
     for each individual command, like define-place, define-monster, etc.
+
+    Each define command works by creating the relevant object, then fleshing
+    it out as more options are passed to it. Finally, the finished object is
+    returned.
     '''
 
     def __init__(self, name, doc_string):
         self.name = name
         self.doc_string = doc_string
-        self.option_registry = []
+        self.option_registry = dict()
 
-    def add_option(self, option_command):
-        self.option_registry.append(option_command)
-
-    def execute(self):
+    def init_object(self, object_name):
         '''
-        Execute this command with all its options
+        Initialize the object this command creates
         '''
-        for o in self.option_registry:
-            o.act(arg)
+        raise NotImplementedError
+
+    def return_object(self):
+        '''
+        Return the type of the game object ('place', 'npc', 'item' or
+        'monster') and the object itself
+        '''
+        raise NotImplementedError
+
+    def pass_option(self, option_name, option_argument):
+        '''
+        Pass this define command one of its options and the relevant argument
+        '''
+        self.option_registry[option_name]["function"](option_argument)
+
+    def add_option(self, option_name, option_docstring, option_function):
+        '''
+        Add an option for this define command. Arguments:
+        option_name: The name of this option as it would appear in
+                     an atl source file
+        option_docstring: A description of this option
+        option_function: The function that this option calls
+                     (this function should take exactly one string argument)
+        '''
+        option_dict = dict["docstring":option_docstring,
+                           "function":option_function]
+        self.option_registry[option_name] = option_dict
 
 
-define_command_registry = []
+define_command_registry = dict()
 
 def register_define_command(def_com):
-    define_command_registry.append(def_com)
+    define_command_registry[def_com.name] = def_com
 
 
 class Parser(object):
     '''
     The actual parser class. It reads in a world file and transforms it into
-    a series of DefineCommands.
+    a series of DefineCommands, which are then executed
     '''
 
-    def __init__(self, world_file):
-        self.world_file = world_file
+    def __init__(self, world_file_name):
+        self.line_command_registry = dict()
+        self.world = World()
+        self.add_line_commands()
+        self.load(world_file_name)
+        return self.world
 
-    def generate_world(self):
-        return World()
+    def load(self, world_file_name):
+        '''
+        Load a world file and pass it on to the interpreter
+        '''
+        try:
+            world_file = open(world_file_name, 'r')
+            atl_text = world_file.readlines()
+            world_file.close()
+        except IOError:
+            print("Failed to load world file '"+world_file_name+"'!")
+        self.interpret_atl(atl_text)
+
+    def add_line_commands(self):
+        '''
+        Line commands are ATL constructs that only take up one line
+        (unlike define commands). All line commands must be registered in
+        this method by adding them to the line_command_registry and setting
+        their key-value to the method to be called when their key appears
+        in an ATL source file.
+        '''
+        self.line_command_registry["load"] = self.load
+        self.line_command_registry["start-place"] = self.world.set_starting_place
+
+    def interpret_atl(self, atl_source):
+        '''
+        This method interprets a list of atl source lines, passing them
+        on to the relevant define commands.
+        '''
+        define_command = None # The define command currently being executed
+        line_no = 0
+        for line in atl_source:
+            # TODO allow for linebreaks
+            line_no = line_no + 1
+            if line[0] == "#":
+                pass #comments are ignored
+            elif (line == "" or line == "\n") and define_command:
+                # Empty lines finish off define blocks
+                object_type, game_object = define_command.return_object()
+                self.world.add_object(object_type, game_object)
+                define_command = None
+            else:
+                print("Line: '"+line+"'")
+                command = line.split()[0]
+                # execute a line command
+                if command in line_command_registry.keys():
+                    line_command_registry[command](line[line.find(" ")+1:])
+                # start of a define block
+                elif command in define_command_registry.keys():
+                    define_command = define_command_registry[command]
+                    object_name = line[line.find(" ")+1:]
+                    define_command.init_object(object_name)
+                # parse an option command
+                elif line[0] == " " or line[0] == "\t":
+                    while line[0] == " " or line[0] == "\t":
+                        line = line[1:]
+                    if line and define_command:
+                        option_command = line.split()[0]
+                        option_arg = line[line.find(" ")+1:]
+                        define_command.pass_option(option_command, option_arg)
+                    else:
+                        # XXX: What should be done here? Do nothing, raise a
+                        # syntax error, or something else?
+                        print("Unrecognized syntax in line "+str(line_no)+"!")
+
diff --git a/src/place.py b/src/place.py
index 8ffd706..eabd30e 100644
--- a/src/place.py
+++ b/src/place.py
@@ -9,7 +9,7 @@
 # date: 02/05/2015
 #
 
-from parser import DefineCommand
+from interpreter import DefineCommand, register_define_command
 
 
 class Place(object):
@@ -18,13 +18,13 @@
     players, monsters, items, NPCs, and links to other places.
     '''
 
-    def __init__(self, name, description,
+    def __init__(self, name, description="",
                  neighbours=[], monsters=[],
                  npc=[], items=[]):
         '''
         The constructor for a new place.
         Arguments:
-        name: the name of this place
+        name: the name of this place (compulsory)
         description: a description string
         neighbours: a list of place names of places bordering on this one
         monsters: a list of instances of monsters
@@ -64,34 +64,33 @@
         self.items.remove(item)
 
 
-#
-# FIXME: conceptually a bit messed up, especially needs work on how the argument
-# gets passed to the OptionCommand
-#
-
-class NeighbourOption(OptionCommand):
-    '''
-    Add a new neighbour to the current place
-    '''
-
-    def __init__(self, arg, place):
-        OptionCommand.__init__("neighbour",
-                               "Add the place given in the argument as a neighbour",
-                               arg)
-        self.place = place
-
-    def act(self, arg):
-        self.place.add_neighbour(arg)
-
-
 class DefinePlace(DefineCommand):
     '''
     The Atlantis language construct to create a place.
     '''
 
-    def __init__(self, place):
+    def __init__(self):
         DefineCommand.__init__("define-place",
                                "Describe a new location in the game world")
-        self.place = place
-        self.add_option(NeighbourOption(self.place))
+        self.add_option("description",
+                        "Describe this place",
+                        set_description)
+        self.add_option("neighbour",
+                        "Add a neighbouring place to this place",
+                        add_neighbour)
+
+    def init_object(self, place_name):
+        self.place = Place(name=place_name)
         
+    def return_object(self):
+        return 'place', self.place
+
+    # This could probably be transformed into a lambda function
+    def add_neighbour(self, arg):
+        self.place.add_neighbour(arg)
+
+    # ...same with this one
+    def set_description(self, arg):
+        self.place.set_description(arg)
+
+register_define_command(DefinePlace())

diff --git a/src/__pycache__/interpreter.cpython-34.pyc b/src/__pycache__/interpreter.cpython-34.pyc
new file mode 100644
index 0000000..56c3add
--- /dev/null
+++ b/src/__pycache__/interpreter.cpython-34.pyc
Binary files differ
diff --git a/src/__pycache__/server.cpython-34.pyc b/src/__pycache__/server.cpython-34.pyc
index 87708fb..e273538 100644
--- a/src/__pycache__/server.cpython-34.pyc
+++ b/src/__pycache__/server.cpython-34.pyc
Binary files differ
diff --git a/src/__pycache__/world.cpython-34.pyc b/src/__pycache__/world.cpython-34.pyc
index f29617b..9f6b508 100644
--- a/src/__pycache__/world.cpython-34.pyc
+++ b/src/__pycache__/world.cpython-34.pyc
Binary files differ
diff --git a/src/atlantis.py b/src/atlantis.py
index ebbb075..2999593 100644
--- a/src/atlantis.py
+++ b/src/atlantis.py
@@ -7,7 +7,7 @@
 # date: 02/05/2015
 #
 
-VERSION = (0, 0, 3) #release, major revision, minor (git) revision
+VERSION = (0, 0, 5) #release, major revision, minor (git) revision
 
 import sys
 import os
@@ -48,7 +48,7 @@
 #TODO!
 def act_on_choice(choice):
     if choice == "s" or choice == "S":
-        print("What port do you want to start the server on?") #indicate range!
+        print("What port do you want to start the server on?") #TODO indicate range!
         server_port = input(">> ")
         print("What world file do you want to load?")
         print("(Specify an absolute or relative path)")
@@ -72,7 +72,7 @@
     else:
         print("Invalid choice!")
         input("Please press ENTER")
-        startMenu()
+        start_menu()
 
 
 def print_version():
@@ -99,9 +99,9 @@
     if "--version" in sys.argv or "-v" in sys.argv: print_version()
     elif "--help" in sys.argv or "-h" in sys.argv: print_help()
     elif "--server" in sys.argv and "--world" in sys.argv:
-        server_port = sys.argv[sys.argv.find("--server")+1]
+        server_port = sys.argv[sys.argv.index("--server")+1]
         world_file = sys.argv[sys.argv.index("--world")+1]
-        Server(port, world_file)
+        Server(server_port, world_file)
     elif "--client" in sys.argv:
         server_address = sys.argv[sys.argv.index("--client")+1]
         server_ip = server_address[:server_address.find(":")]
diff --git a/src/interpreter.py b/src/interpreter.py
index 86cd37e..6db846e 100644
--- a/src/interpreter.py
+++ b/src/interpreter.py
@@ -12,67 +12,134 @@
 from world import World
 
 
-#
-# FIXME: conceptually a bit messed up, especially needs work on how the argument
-# gets passed to the OptionCommand
-#
-
-
-class OptionCommand(object):
-    '''
-    This is the super class for all option commands. (A define command
-    includes one or more option commands.)
-    '''
-
-    def __init__(self, name, doc_string, arg):
-        self.name = name
-        self.doc_string = doc_string
-        self.arg = arg
-
-    def act(self):
-        '''
-        Carry out this option commands action with argument arg.
-        Has to be extended by subclasses!
-        '''
-        raise NotImplementedError
-
-
 class DefineCommand(object):
     '''
     This is the super class for all define commands. It should be extended
     for each individual command, like define-place, define-monster, etc.
+
+    Each define command works by creating the relevant object, then fleshing
+    it out as more options are passed to it. Finally, the finished object is
+    returned.
     '''
 
     def __init__(self, name, doc_string):
         self.name = name
         self.doc_string = doc_string
-        self.option_registry = []
+        self.option_registry = dict()
 
-    def add_option(self, option_command):
-        self.option_registry.append(option_command)
-
-    def execute(self):
+    def init_object(self, object_name):
         '''
-        Execute this command with all its options
+        Initialize the object this command creates
         '''
-        for o in self.option_registry:
-            o.act(arg)
+        raise NotImplementedError
+
+    def return_object(self):
+        '''
+        Return the type of the game object ('place', 'npc', 'item' or
+        'monster') and the object itself
+        '''
+        raise NotImplementedError
+
+    def pass_option(self, option_name, option_argument):
+        '''
+        Pass this define command one of its options and the relevant argument
+        '''
+        self.option_registry[option_name]["function"](option_argument)
+
+    def add_option(self, option_name, option_docstring, option_function):
+        '''
+        Add an option for this define command. Arguments:
+        option_name: The name of this option as it would appear in
+                     an atl source file
+        option_docstring: A description of this option
+        option_function: The function that this option calls
+                     (this function should take exactly one string argument)
+        '''
+        option_dict = dict["docstring":option_docstring,
+                           "function":option_function]
+        self.option_registry[option_name] = option_dict
 
 
-define_command_registry = []
+define_command_registry = dict()
 
 def register_define_command(def_com):
-    define_command_registry.append(def_com)
+    define_command_registry[def_com.name] = def_com
 
 
 class Parser(object):
     '''
     The actual parser class. It reads in a world file and transforms it into
-    a series of DefineCommands.
+    a series of DefineCommands, which are then executed
     '''
 
-    def __init__(self, world_file):
-        self.world_file = world_file
+    def __init__(self, world_file_name):
+        self.line_command_registry = dict()
+        self.world = World()
+        self.add_line_commands()
+        self.load(world_file_name)
+        return self.world
 
-    def generate_world(self):
-        return World()
+    def load(self, world_file_name):
+        '''
+        Load a world file and pass it on to the interpreter
+        '''
+        try:
+            world_file = open(world_file_name, 'r')
+            atl_text = world_file.readlines()
+            world_file.close()
+        except IOError:
+            print("Failed to load world file '"+world_file_name+"'!")
+        self.interpret_atl(atl_text)
+
+    def add_line_commands(self):
+        '''
+        Line commands are ATL constructs that only take up one line
+        (unlike define commands). All line commands must be registered in
+        this method by adding them to the line_command_registry and setting
+        their key-value to the method to be called when their key appears
+        in an ATL source file.
+        '''
+        self.line_command_registry["load"] = self.load
+        self.line_command_registry["start-place"] = self.world.set_starting_place
+
+    def interpret_atl(self, atl_source):
+        '''
+        This method interprets a list of atl source lines, passing them
+        on to the relevant define commands.
+        '''
+        define_command = None # The define command currently being executed
+        line_no = 0
+        for line in atl_source:
+            # TODO allow for linebreaks
+            line_no = line_no + 1
+            if line[0] == "#":
+                pass #comments are ignored
+            elif (line == "" or line == "\n") and define_command:
+                # Empty lines finish off define blocks
+                object_type, game_object = define_command.return_object()
+                self.world.add_object(object_type, game_object)
+                define_command = None
+            else:
+                print("Line: '"+line+"'")
+                command = line.split()[0]
+                # execute a line command
+                if command in line_command_registry.keys():
+                    line_command_registry[command](line[line.find(" ")+1:])
+                # start of a define block
+                elif command in define_command_registry.keys():
+                    define_command = define_command_registry[command]
+                    object_name = line[line.find(" ")+1:]
+                    define_command.init_object(object_name)
+                # parse an option command
+                elif line[0] == " " or line[0] == "\t":
+                    while line[0] == " " or line[0] == "\t":
+                        line = line[1:]
+                    if line and define_command:
+                        option_command = line.split()[0]
+                        option_arg = line[line.find(" ")+1:]
+                        define_command.pass_option(option_command, option_arg)
+                    else:
+                        # XXX: What should be done here? Do nothing, raise a
+                        # syntax error, or something else?
+                        print("Unrecognized syntax in line "+str(line_no)+"!")
+
diff --git a/src/place.py b/src/place.py
index 8ffd706..eabd30e 100644
--- a/src/place.py
+++ b/src/place.py
@@ -9,7 +9,7 @@
 # date: 02/05/2015
 #
 
-from parser import DefineCommand
+from interpreter import DefineCommand, register_define_command
 
 
 class Place(object):
@@ -18,13 +18,13 @@
     players, monsters, items, NPCs, and links to other places.
     '''
 
-    def __init__(self, name, description,
+    def __init__(self, name, description="",
                  neighbours=[], monsters=[],
                  npc=[], items=[]):
         '''
         The constructor for a new place.
         Arguments:
-        name: the name of this place
+        name: the name of this place (compulsory)
         description: a description string
         neighbours: a list of place names of places bordering on this one
         monsters: a list of instances of monsters
@@ -64,34 +64,33 @@
         self.items.remove(item)
 
 
-#
-# FIXME: conceptually a bit messed up, especially needs work on how the argument
-# gets passed to the OptionCommand
-#
-
-class NeighbourOption(OptionCommand):
-    '''
-    Add a new neighbour to the current place
-    '''
-
-    def __init__(self, arg, place):
-        OptionCommand.__init__("neighbour",
-                               "Add the place given in the argument as a neighbour",
-                               arg)
-        self.place = place
-
-    def act(self, arg):
-        self.place.add_neighbour(arg)
-
-
 class DefinePlace(DefineCommand):
     '''
     The Atlantis language construct to create a place.
     '''
 
-    def __init__(self, place):
+    def __init__(self):
         DefineCommand.__init__("define-place",
                                "Describe a new location in the game world")
-        self.place = place
-        self.add_option(NeighbourOption(self.place))
+        self.add_option("description",
+                        "Describe this place",
+                        set_description)
+        self.add_option("neighbour",
+                        "Add a neighbouring place to this place",
+                        add_neighbour)
+
+    def init_object(self, place_name):
+        self.place = Place(name=place_name)
         
+    def return_object(self):
+        return 'place', self.place
+
+    # This could probably be transformed into a lambda function
+    def add_neighbour(self, arg):
+        self.place.add_neighbour(arg)
+
+    # ...same with this one
+    def set_description(self, arg):
+        self.place.set_description(arg)
+
+register_define_command(DefinePlace())
diff --git a/src/server.py b/src/server.py
index aaecbb4..8c6b6ea 100644
--- a/src/server.py
+++ b/src/server.py
@@ -8,7 +8,7 @@
 # date: 02/05/2015
 #
 
-from parser import Parser
+from interpreter import Parser
 
 #TODO: lock file for the server!
 
@@ -22,5 +22,12 @@
         print("The server is still under construction!")
         self.port = port
         self.world_file = world_file
-        parser = Parser(self.world_file)
-        self.world = parser.generate_world()
+        self.world = Parser(self.world_file)
+        test_parser()
+
+    def test_parser(self):
+        print("World loaded. Details:")
+        places = self.world.places.keys()
+        for p in places:
+            print("Place: "+self.world.get_place(p).name)
+            print("Neighbours: "+self.world.get_place(p).neighbours+"\n")

diff --git a/src/__pycache__/interpreter.cpython-34.pyc b/src/__pycache__/interpreter.cpython-34.pyc
new file mode 100644
index 0000000..56c3add
--- /dev/null
+++ b/src/__pycache__/interpreter.cpython-34.pyc
Binary files differ
diff --git a/src/__pycache__/server.cpython-34.pyc b/src/__pycache__/server.cpython-34.pyc
index 87708fb..e273538 100644
--- a/src/__pycache__/server.cpython-34.pyc
+++ b/src/__pycache__/server.cpython-34.pyc
Binary files differ
diff --git a/src/__pycache__/world.cpython-34.pyc b/src/__pycache__/world.cpython-34.pyc
index f29617b..9f6b508 100644
--- a/src/__pycache__/world.cpython-34.pyc
+++ b/src/__pycache__/world.cpython-34.pyc
Binary files differ
diff --git a/src/atlantis.py b/src/atlantis.py
index ebbb075..2999593 100644
--- a/src/atlantis.py
+++ b/src/atlantis.py
@@ -7,7 +7,7 @@
 # date: 02/05/2015
 #
 
-VERSION = (0, 0, 3) #release, major revision, minor (git) revision
+VERSION = (0, 0, 5) #release, major revision, minor (git) revision
 
 import sys
 import os
@@ -48,7 +48,7 @@
 #TODO!
 def act_on_choice(choice):
     if choice == "s" or choice == "S":
-        print("What port do you want to start the server on?") #indicate range!
+        print("What port do you want to start the server on?") #TODO indicate range!
         server_port = input(">> ")
         print("What world file do you want to load?")
         print("(Specify an absolute or relative path)")
@@ -72,7 +72,7 @@
     else:
         print("Invalid choice!")
         input("Please press ENTER")
-        startMenu()
+        start_menu()
 
 
 def print_version():
@@ -99,9 +99,9 @@
     if "--version" in sys.argv or "-v" in sys.argv: print_version()
     elif "--help" in sys.argv or "-h" in sys.argv: print_help()
     elif "--server" in sys.argv and "--world" in sys.argv:
-        server_port = sys.argv[sys.argv.find("--server")+1]
+        server_port = sys.argv[sys.argv.index("--server")+1]
         world_file = sys.argv[sys.argv.index("--world")+1]
-        Server(port, world_file)
+        Server(server_port, world_file)
     elif "--client" in sys.argv:
         server_address = sys.argv[sys.argv.index("--client")+1]
         server_ip = server_address[:server_address.find(":")]
diff --git a/src/interpreter.py b/src/interpreter.py
index 86cd37e..6db846e 100644
--- a/src/interpreter.py
+++ b/src/interpreter.py
@@ -12,67 +12,134 @@
 from world import World
 
 
-#
-# FIXME: conceptually a bit messed up, especially needs work on how the argument
-# gets passed to the OptionCommand
-#
-
-
-class OptionCommand(object):
-    '''
-    This is the super class for all option commands. (A define command
-    includes one or more option commands.)
-    '''
-
-    def __init__(self, name, doc_string, arg):
-        self.name = name
-        self.doc_string = doc_string
-        self.arg = arg
-
-    def act(self):
-        '''
-        Carry out this option commands action with argument arg.
-        Has to be extended by subclasses!
-        '''
-        raise NotImplementedError
-
-
 class DefineCommand(object):
     '''
     This is the super class for all define commands. It should be extended
     for each individual command, like define-place, define-monster, etc.
+
+    Each define command works by creating the relevant object, then fleshing
+    it out as more options are passed to it. Finally, the finished object is
+    returned.
     '''
 
     def __init__(self, name, doc_string):
         self.name = name
         self.doc_string = doc_string
-        self.option_registry = []
+        self.option_registry = dict()
 
-    def add_option(self, option_command):
-        self.option_registry.append(option_command)
-
-    def execute(self):
+    def init_object(self, object_name):
         '''
-        Execute this command with all its options
+        Initialize the object this command creates
         '''
-        for o in self.option_registry:
-            o.act(arg)
+        raise NotImplementedError
+
+    def return_object(self):
+        '''
+        Return the type of the game object ('place', 'npc', 'item' or
+        'monster') and the object itself
+        '''
+        raise NotImplementedError
+
+    def pass_option(self, option_name, option_argument):
+        '''
+        Pass this define command one of its options and the relevant argument
+        '''
+        self.option_registry[option_name]["function"](option_argument)
+
+    def add_option(self, option_name, option_docstring, option_function):
+        '''
+        Add an option for this define command. Arguments:
+        option_name: The name of this option as it would appear in
+                     an atl source file
+        option_docstring: A description of this option
+        option_function: The function that this option calls
+                     (this function should take exactly one string argument)
+        '''
+        option_dict = dict["docstring":option_docstring,
+                           "function":option_function]
+        self.option_registry[option_name] = option_dict
 
 
-define_command_registry = []
+define_command_registry = dict()
 
 def register_define_command(def_com):
-    define_command_registry.append(def_com)
+    define_command_registry[def_com.name] = def_com
 
 
 class Parser(object):
     '''
     The actual parser class. It reads in a world file and transforms it into
-    a series of DefineCommands.
+    a series of DefineCommands, which are then executed
     '''
 
-    def __init__(self, world_file):
-        self.world_file = world_file
+    def __init__(self, world_file_name):
+        self.line_command_registry = dict()
+        self.world = World()
+        self.add_line_commands()
+        self.load(world_file_name)
+        return self.world
 
-    def generate_world(self):
-        return World()
+    def load(self, world_file_name):
+        '''
+        Load a world file and pass it on to the interpreter
+        '''
+        try:
+            world_file = open(world_file_name, 'r')
+            atl_text = world_file.readlines()
+            world_file.close()
+        except IOError:
+            print("Failed to load world file '"+world_file_name+"'!")
+        self.interpret_atl(atl_text)
+
+    def add_line_commands(self):
+        '''
+        Line commands are ATL constructs that only take up one line
+        (unlike define commands). All line commands must be registered in
+        this method by adding them to the line_command_registry and setting
+        their key-value to the method to be called when their key appears
+        in an ATL source file.
+        '''
+        self.line_command_registry["load"] = self.load
+        self.line_command_registry["start-place"] = self.world.set_starting_place
+
+    def interpret_atl(self, atl_source):
+        '''
+        This method interprets a list of atl source lines, passing them
+        on to the relevant define commands.
+        '''
+        define_command = None # The define command currently being executed
+        line_no = 0
+        for line in atl_source:
+            # TODO allow for linebreaks
+            line_no = line_no + 1
+            if line[0] == "#":
+                pass #comments are ignored
+            elif (line == "" or line == "\n") and define_command:
+                # Empty lines finish off define blocks
+                object_type, game_object = define_command.return_object()
+                self.world.add_object(object_type, game_object)
+                define_command = None
+            else:
+                print("Line: '"+line+"'")
+                command = line.split()[0]
+                # execute a line command
+                if command in line_command_registry.keys():
+                    line_command_registry[command](line[line.find(" ")+1:])
+                # start of a define block
+                elif command in define_command_registry.keys():
+                    define_command = define_command_registry[command]
+                    object_name = line[line.find(" ")+1:]
+                    define_command.init_object(object_name)
+                # parse an option command
+                elif line[0] == " " or line[0] == "\t":
+                    while line[0] == " " or line[0] == "\t":
+                        line = line[1:]
+                    if line and define_command:
+                        option_command = line.split()[0]
+                        option_arg = line[line.find(" ")+1:]
+                        define_command.pass_option(option_command, option_arg)
+                    else:
+                        # XXX: What should be done here? Do nothing, raise a
+                        # syntax error, or something else?
+                        print("Unrecognized syntax in line "+str(line_no)+"!")
+
diff --git a/src/place.py b/src/place.py
index 8ffd706..eabd30e 100644
--- a/src/place.py
+++ b/src/place.py
@@ -9,7 +9,7 @@
 # date: 02/05/2015
 #
 
-from parser import DefineCommand
+from interpreter import DefineCommand, register_define_command
 
 
 class Place(object):
@@ -18,13 +18,13 @@
     players, monsters, items, NPCs, and links to other places.
     '''
 
-    def __init__(self, name, description,
+    def __init__(self, name, description="",
                  neighbours=[], monsters=[],
                  npc=[], items=[]):
         '''
         The constructor for a new place.
         Arguments:
-        name: the name of this place
+        name: the name of this place (compulsory)
         description: a description string
         neighbours: a list of place names of places bordering on this one
         monsters: a list of instances of monsters
@@ -64,34 +64,33 @@
         self.items.remove(item)
 
 
-#
-# FIXME: conceptually a bit messed up, especially needs work on how the argument
-# gets passed to the OptionCommand
-#
-
-class NeighbourOption(OptionCommand):
-    '''
-    Add a new neighbour to the current place
-    '''
-
-    def __init__(self, arg, place):
-        OptionCommand.__init__("neighbour",
-                               "Add the place given in the argument as a neighbour",
-                               arg)
-        self.place = place
-
-    def act(self, arg):
-        self.place.add_neighbour(arg)
-
-
 class DefinePlace(DefineCommand):
     '''
     The Atlantis language construct to create a place.
     '''
 
-    def __init__(self, place):
+    def __init__(self):
         DefineCommand.__init__("define-place",
                                "Describe a new location in the game world")
-        self.place = place
-        self.add_option(NeighbourOption(self.place))
+        self.add_option("description",
+                        "Describe this place",
+                        set_description)
+        self.add_option("neighbour",
+                        "Add a neighbouring place to this place",
+                        add_neighbour)
+
+    def init_object(self, place_name):
+        self.place = Place(name=place_name)
         
+    def return_object(self):
+        return 'place', self.place
+
+    # This could probably be transformed into a lambda function
+    def add_neighbour(self, arg):
+        self.place.add_neighbour(arg)
+
+    # ...same with this one
+    def set_description(self, arg):
+        self.place.set_description(arg)
+
+register_define_command(DefinePlace())
diff --git a/src/server.py b/src/server.py
index aaecbb4..8c6b6ea 100644
--- a/src/server.py
+++ b/src/server.py
@@ -8,7 +8,7 @@
 # date: 02/05/2015
 #
 
-from parser import Parser
+from interpreter import Parser
 
 #TODO: lock file for the server!
 
@@ -22,5 +22,12 @@
         print("The server is still under construction!")
         self.port = port
         self.world_file = world_file
-        parser = Parser(self.world_file)
-        self.world = parser.generate_world()
+        self.world = Parser(self.world_file)
+        test_parser()
+
+    def test_parser(self):
+        print("World loaded. Details:")
+        places = self.world.places.keys()
+        for p in places:
+            print("Place: "+self.world.get_place(p).name)
+            print("Neighbours: "+self.world.get_place(p).neighbours+"\n")
diff --git a/src/world.py b/src/world.py
index 0c2fe32..aaacc17 100644
--- a/src/world.py
+++ b/src/world.py
@@ -8,6 +8,9 @@
 # date: 02/05/2015
 #
 
+import copy
+
+
 class World(object):
     '''
     The World class saves and gives access to the current state
@@ -15,39 +18,86 @@
     '''
 
     def __init__(self):
-        self.places = []
-        self.players = []
+        '''
+        The constructor initializes dicts consisting of name:object pairs
+        for all the places, players, NPCs, items and monsters available in
+        the world.
+        '''
+        self.places = dict()
+        self.players = dict()
         self.starting_place = None
-
-    def register_place(self, place):
-        if self.place not in places:
-            self.places.append(place)
-        else:
-            print("Attempted to add a place that already exists!")
-
+        self.npc = dict()
+        self.items = dict()
+        self.monsters = dict()
+        
     def register_player(self, player):
-        if player not in self.players:
-            self.players.append(player)
+        if player.name not in self.players.keys():
             if player.place == None:
                 if self.starting_place:
                     player.place = self.starting_place
                 else:
                     print("No starting place set!")
+            self.players[player.name] = player
         else:
             print("Attempted to add a player that already exists!")
 
-    def get_place(self, name):
-        for p in self.places:
-            if p.name == name:
-                return p
+    def add_object(self, object_type, game_object):
+        '''
+        Add a game object to the world. Acts as a wrapper around add_place, etc.
+        object_type: 'place', 'npc', 'item' or 'monster'
+        game_object: the actual object
+        '''
+        if object_type == "place":
+            add_place(game_object)
+        elif object_type == "npc":
+            add_npc(game_object)
+        elif object_type == "item":
+            add_item(game_object)
+        elif object_type == "monster":
+            add_monster(game_object)
+            
+    def add_place(self, place):
+        self.places[place.name] = place
+
+    def add_monster(self, monster):
+        self.monsters[monster.name] = monster
+
+    def add_npc(self, npc):
+        self.npc[npc.name] = npc
+
+    def add_item(self, item):
+        self.items[item.name] = item
 
     def get_player(self, name):
-        for p in self.players:
-            if p.name == name:
-                return p
+        return self.players[name]
 
-    def set_starting_place(self, name):
-        for p in self.places:
-            if p.name == name:
-                self.starting_place = p
+    def get_place(self, name):
+        return self.places[name]
+        
+    def set_starting_place(self, place_name):
+        self.starting_place = place_name
 
+    def get_npc(self, npc_name):
+        return self.npc[npc_name]
+
+    def get_item(self, item_name):
+        '''
+        Returns a copy of the item object stored under the passed name.
+        This means that World retains a "pure" instance of every item type
+        for future reference. Each Place holds its own item objects that
+        can be changed or removed at will.
+        '''
+        # is deepcopy the right copy method to use? if shallow copy is
+        # sufficient, we could just use the inbuilt dict.copy()
+        return copy.deepcopy(self.items[item_name])        
+
+    def get_monster(self, monster_name):
+        '''
+        Returns a copy of the monster object stored under the passed name.
+        This means that World retains a "pure" instance of every monster type
+        for future reference. Each Place holds its own monster objects that
+        can be changed at will (e.g. in a fight).
+        '''
+        # is deepcopy the right copy method to use? if shallow copy is
+        # sufficient, we could just use the inbuilt dict.copy()
+        return copy.deepcopy(self.monsters[monster_name])

diff --git a/src/__pycache__/interpreter.cpython-34.pyc b/src/__pycache__/interpreter.cpython-34.pyc
new file mode 100644
index 0000000..56c3add
--- /dev/null
+++ b/src/__pycache__/interpreter.cpython-34.pyc
Binary files differ
diff --git a/src/__pycache__/server.cpython-34.pyc b/src/__pycache__/server.cpython-34.pyc
index 87708fb..e273538 100644
--- a/src/__pycache__/server.cpython-34.pyc
+++ b/src/__pycache__/server.cpython-34.pyc
Binary files differ
diff --git a/src/__pycache__/world.cpython-34.pyc b/src/__pycache__/world.cpython-34.pyc
index f29617b..9f6b508 100644
--- a/src/__pycache__/world.cpython-34.pyc
+++ b/src/__pycache__/world.cpython-34.pyc
Binary files differ
diff --git a/src/atlantis.py b/src/atlantis.py
index ebbb075..2999593 100644
--- a/src/atlantis.py
+++ b/src/atlantis.py
@@ -7,7 +7,7 @@
 # date: 02/05/2015
 #
 
-VERSION = (0, 0, 3) #release, major revision, minor (git) revision
+VERSION = (0, 0, 5) #release, major revision, minor (git) revision
 
 import sys
 import os
@@ -48,7 +48,7 @@
 #TODO!
 def act_on_choice(choice):
     if choice == "s" or choice == "S":
-        print("What port do you want to start the server on?") #indicate range!
+        print("What port do you want to start the server on?") #TODO indicate range!
         server_port = input(">> ")
         print("What world file do you want to load?")
         print("(Specify an absolute or relative path)")
@@ -72,7 +72,7 @@
     else:
         print("Invalid choice!")
         input("Please press ENTER")
-        startMenu()
+        start_menu()
 
 
 def print_version():
@@ -99,9 +99,9 @@
     if "--version" in sys.argv or "-v" in sys.argv: print_version()
     elif "--help" in sys.argv or "-h" in sys.argv: print_help()
     elif "--server" in sys.argv and "--world" in sys.argv:
-        server_port = sys.argv[sys.argv.find("--server")+1]
+        server_port = sys.argv[sys.argv.index("--server")+1]
         world_file = sys.argv[sys.argv.index("--world")+1]
-        Server(port, world_file)
+        Server(server_port, world_file)
     elif "--client" in sys.argv:
         server_address = sys.argv[sys.argv.index("--client")+1]
         server_ip = server_address[:server_address.find(":")]
diff --git a/src/interpreter.py b/src/interpreter.py
index 86cd37e..6db846e 100644
--- a/src/interpreter.py
+++ b/src/interpreter.py
@@ -12,67 +12,134 @@
 from world import World
 
 
-#
-# FIXME: conceptually a bit messed up, especially needs work on how the argument
-# gets passed to the OptionCommand
-#
-
-
-class OptionCommand(object):
-    '''
-    This is the super class for all option commands. (A define command
-    includes one or more option commands.)
-    '''
-
-    def __init__(self, name, doc_string, arg):
-        self.name = name
-        self.doc_string = doc_string
-        self.arg = arg
-
-    def act(self):
-        '''
-        Carry out this option commands action with argument arg.
-        Has to be extended by subclasses!
-        '''
-        raise NotImplementedError
-
-
 class DefineCommand(object):
     '''
     This is the super class for all define commands. It should be extended
     for each individual command, like define-place, define-monster, etc.
+
+    Each define command works by creating the relevant object, then fleshing
+    it out as more options are passed to it. Finally, the finished object is
+    returned.
     '''
 
     def __init__(self, name, doc_string):
         self.name = name
         self.doc_string = doc_string
-        self.option_registry = []
+        self.option_registry = dict()
 
-    def add_option(self, option_command):
-        self.option_registry.append(option_command)
-
-    def execute(self):
+    def init_object(self, object_name):
         '''
-        Execute this command with all its options
+        Initialize the object this command creates
         '''
-        for o in self.option_registry:
-            o.act(arg)
+        raise NotImplementedError
+
+    def return_object(self):
+        '''
+        Return the type of the game object ('place', 'npc', 'item' or
+        'monster') and the object itself
+        '''
+        raise NotImplementedError
+
+    def pass_option(self, option_name, option_argument):
+        '''
+        Pass this define command one of its options and the relevant argument
+        '''
+        self.option_registry[option_name]["function"](option_argument)
+
+    def add_option(self, option_name, option_docstring, option_function):
+        '''
+        Add an option for this define command. Arguments:
+        option_name: The name of this option as it would appear in
+                     an atl source file
+        option_docstring: A description of this option
+        option_function: The function that this option calls
+                     (this function should take exactly one string argument)
+        '''
+        option_dict = dict["docstring":option_docstring,
+                           "function":option_function]
+        self.option_registry[option_name] = option_dict
 
 
-define_command_registry = []
+define_command_registry = dict()
 
 def register_define_command(def_com):
-    define_command_registry.append(def_com)
+    define_command_registry[def_com.name] = def_com
 
 
 class Parser(object):
     '''
     The actual parser class. It reads in a world file and transforms it into
-    a series of DefineCommands.
+    a series of DefineCommands, which are then executed
     '''
 
-    def __init__(self, world_file):
-        self.world_file = world_file
+    def __init__(self, world_file_name):
+        self.line_command_registry = dict()
+        self.world = World()
+        self.add_line_commands()
+        self.load(world_file_name)
+        return self.world
 
-    def generate_world(self):
-        return World()
+    def load(self, world_file_name):
+        '''
+        Load a world file and pass it on to the interpreter
+        '''
+        try:
+            world_file = open(world_file_name, 'r')
+            atl_text = world_file.readlines()
+            world_file.close()
+        except IOError:
+            print("Failed to load world file '"+world_file_name+"'!")
+        self.interpret_atl(atl_text)
+
+    def add_line_commands(self):
+        '''
+        Line commands are ATL constructs that only take up one line
+        (unlike define commands). All line commands must be registered in
+        this method by adding them to the line_command_registry and setting
+        their key-value to the method to be called when their key appears
+        in an ATL source file.
+        '''
+        self.line_command_registry["load"] = self.load
+        self.line_command_registry["start-place"] = self.world.set_starting_place
+
+    def interpret_atl(self, atl_source):
+        '''
+        This method interprets a list of atl source lines, passing them
+        on to the relevant define commands.
+        '''
+        define_command = None # The define command currently being executed
+        line_no = 0
+        for line in atl_source:
+            # TODO allow for linebreaks
+            line_no = line_no + 1
+            if line[0] == "#":
+                pass #comments are ignored
+            elif (line == "" or line == "\n") and define_command:
+                # Empty lines finish off define blocks
+                object_type, game_object = define_command.return_object()
+                self.world.add_object(object_type, game_object)
+                define_command = None
+            else:
+                print("Line: '"+line+"'")
+                command = line.split()[0]
+                # execute a line command
+                if command in line_command_registry.keys():
+                    line_command_registry[command](line[line.find(" ")+1:])
+                # start of a define block
+                elif command in define_command_registry.keys():
+                    define_command = define_command_registry[command]
+                    object_name = line[line.find(" ")+1:]
+                    define_command.init_object(object_name)
+                # parse an option command
+                elif line[0] == " " or line[0] == "\t":
+                    while line[0] == " " or line[0] == "\t":
+                        line = line[1:]
+                    if line and define_command:
+                        option_command = line.split()[0]
+                        option_arg = line[line.find(" ")+1:]
+                        define_command.pass_option(option_command, option_arg)
+                    else:
+                        # XXX: What should be done here? Do nothing, raise a
+                        # syntax error, or something else?
+                        print("Unrecognized syntax in line "+str(line_no)+"!")
+
diff --git a/src/place.py b/src/place.py
index 8ffd706..eabd30e 100644
--- a/src/place.py
+++ b/src/place.py
@@ -9,7 +9,7 @@
 # date: 02/05/2015
 #
 
-from parser import DefineCommand
+from interpreter import DefineCommand, register_define_command
 
 
 class Place(object):
@@ -18,13 +18,13 @@
     players, monsters, items, NPCs, and links to other places.
     '''
 
-    def __init__(self, name, description,
+    def __init__(self, name, description="",
                  neighbours=[], monsters=[],
                  npc=[], items=[]):
         '''
         The constructor for a new place.
         Arguments:
-        name: the name of this place
+        name: the name of this place (compulsory)
         description: a description string
         neighbours: a list of place names of places bordering on this one
         monsters: a list of instances of monsters
@@ -64,34 +64,33 @@
         self.items.remove(item)
 
 
-#
-# FIXME: conceptually a bit messed up, especially needs work on how the argument
-# gets passed to the OptionCommand
-#
-
-class NeighbourOption(OptionCommand):
-    '''
-    Add a new neighbour to the current place
-    '''
-
-    def __init__(self, arg, place):
-        OptionCommand.__init__("neighbour",
-                               "Add the place given in the argument as a neighbour",
-                               arg)
-        self.place = place
-
-    def act(self, arg):
-        self.place.add_neighbour(arg)
-
-
 class DefinePlace(DefineCommand):
     '''
     The Atlantis language construct to create a place.
     '''
 
-    def __init__(self, place):
+    def __init__(self):
         DefineCommand.__init__("define-place",
                                "Describe a new location in the game world")
-        self.place = place
-        self.add_option(NeighbourOption(self.place))
+        self.add_option("description",
+                        "Describe this place",
+                        set_description)
+        self.add_option("neighbour",
+                        "Add a neighbouring place to this place",
+                        add_neighbour)
+
+    def init_object(self, place_name):
+        self.place = Place(name=place_name)
         
+    def return_object(self):
+        return 'place', self.place
+
+    # This could probably be transformed into a lambda function
+    def add_neighbour(self, arg):
+        self.place.add_neighbour(arg)
+
+    # ...same with this one
+    def set_description(self, arg):
+        self.place.set_description(arg)
+
+register_define_command(DefinePlace())
diff --git a/src/server.py b/src/server.py
index aaecbb4..8c6b6ea 100644
--- a/src/server.py
+++ b/src/server.py
@@ -8,7 +8,7 @@
 # date: 02/05/2015
 #
 
-from parser import Parser
+from interpreter import Parser
 
 #TODO: lock file for the server!
 
@@ -22,5 +22,12 @@
         print("The server is still under construction!")
         self.port = port
         self.world_file = world_file
-        parser = Parser(self.world_file)
-        self.world = parser.generate_world()
+        self.world = Parser(self.world_file)
+        test_parser()
+
+    def test_parser(self):
+        print("World loaded. Details:")
+        places = self.world.places.keys()
+        for p in places:
+            print("Place: "+self.world.get_place(p).name)
+            print("Neighbours: "+self.world.get_place(p).neighbours+"\n")
diff --git a/src/world.py b/src/world.py
index 0c2fe32..aaacc17 100644
--- a/src/world.py
+++ b/src/world.py
@@ -8,6 +8,9 @@
 # date: 02/05/2015
 #
 
+import copy
+
+
 class World(object):
     '''
     The World class saves and gives access to the current state
@@ -15,39 +18,86 @@
     '''
 
     def __init__(self):
-        self.places = []
-        self.players = []
+        '''
+        The constructor initializes dicts consisting of name:object pairs
+        for all the places, players, NPCs, items and monsters available in
+        the world.
+        '''
+        self.places = dict()
+        self.players = dict()
         self.starting_place = None
-
-    def register_place(self, place):
-        if self.place not in places:
-            self.places.append(place)
-        else:
-            print("Attempted to add a place that already exists!")
-
+        self.npc = dict()
+        self.items = dict()
+        self.monsters = dict()
+        
     def register_player(self, player):
-        if player not in self.players:
-            self.players.append(player)
+        if player.name not in self.players.keys():
             if player.place == None:
                 if self.starting_place:
                     player.place = self.starting_place
                 else:
                     print("No starting place set!")
+            self.players[player.name] = player
         else:
             print("Attempted to add a player that already exists!")
 
-    def get_place(self, name):
-        for p in self.places:
-            if p.name == name:
-                return p
+    def add_object(self, object_type, game_object):
+        '''
+        Add a game object to the world. Acts as a wrapper around add_place, etc.
+        object_type: 'place', 'npc', 'item' or 'monster'
+        game_object: the actual object
+        '''
+        if object_type == "place":
+            add_place(game_object)
+        elif object_type == "npc":
+            add_npc(game_object)
+        elif object_type == "item":
+            add_item(game_object)
+        elif object_type == "monster":
+            add_monster(game_object)
+            
+    def add_place(self, place):
+        self.places[place.name] = place
+
+    def add_monster(self, monster):
+        self.monsters[monster.name] = monster
+
+    def add_npc(self, npc):
+        self.npc[npc.name] = npc
+
+    def add_item(self, item):
+        self.items[item.name] = item
 
     def get_player(self, name):
-        for p in self.players:
-            if p.name == name:
-                return p
+        return self.players[name]
 
-    def set_starting_place(self, name):
-        for p in self.places:
-            if p.name == name:
-                self.starting_place = p
+    def get_place(self, name):
+        return self.places[name]
+        
+    def set_starting_place(self, place_name):
+        self.starting_place = place_name
 
+    def get_npc(self, npc_name):
+        return self.npc[npc_name]
+
+    def get_item(self, item_name):
+        '''
+        Returns a copy of the item object stored under the passed name.
+        This means that World retains a "pure" instance of every item type
+        for future reference. Each Place holds its own item objects that
+        can be changed or removed at will.
+        '''
+        # is deepcopy the right copy method to use? if shallow copy is
+        # sufficient, we could just use the inbuilt dict.copy()
+        return copy.deepcopy(self.items[item_name])        
+
+    def get_monster(self, monster_name):
+        '''
+        Returns a copy of the monster object stored under the passed name.
+        This means that World retains a "pure" instance of every monster type
+        for future reference. Each Place holds its own monster objects that
+        can be changed at will (e.g. in a fight).
+        '''
+        # is deepcopy the right copy method to use? if shallow copy is
+        # sufficient, we could just use the inbuilt dict.copy()
+        return copy.deepcopy(self.monsters[monster_name])
diff --git a/worlds/Example/test.atl b/worlds/Example/test.atl
new file mode 100644
index 0000000..b855b0a
--- /dev/null
+++ b/worlds/Example/test.atl
@@ -0,0 +1,12 @@
+# This is a simple test ATL file to test whatever I have implemented so far.
+# @author Daniel Vedder
+# @date 04/05/2015
+
+define-place Nowhere
+	description Welcome to Nowhere! 
+#You are in the void, the space between \
+#the worlds. Around you is black. Black, except for one tiny pin-prick of 
+#light \to the north.
+	neighbour Elysium
+
+start-place Nowhere
\ No newline at end of file