refactor: improve code readability

dopey.py

@@ -2,19 +2,20 @@ import sys
 from io import TextIOWrapper
 from blessed import Terminal
 
-# create memory buffer and pointer
+class MismatchBracketException(Exception):
+    """ TODO line number and column """
+    pass
+
 class Memory:
     BUFFER_SIZE = 30_000
     buffer = [0 for _ in range(BUFFER_SIZE)]
     pointer = 0
-    loop_stack = []
 
     @classmethod
     def get_pointer(cls) -> int:
         # TODO add logic to roll around buffer
         return cls.pointer
 
-# define bf commands
 class Operation:
     SHIFT_LEFT = "<"
     SHIFT_RIGHT = ">"
@@ -25,8 +26,73 @@ class Operation:
     OPEN_LOOP = "["
     CLOSE_LOOP = "]"
 
+    terminal = Terminal()
+    loop_stack = []
+
+    @classmethod
+    def perform(cls, operation: str, file: TextIOWrapper) -> None:
+        switch = {
+            cls.SHIFT_LEFT: cls.shift_left,
+            cls.SHIFT_RIGHT: cls.shift_right,
+            cls.INCREMENT: cls.increment,
+            cls.DECREMENT: cls.decrement,
+            cls.OUTPUT: cls.output,
+            cls.INPUT: cls.input,
+            cls.OPEN_LOOP: cls.open_loop,
+            cls.CLOSE_LOOP: cls.close_loop
+        }
+
+        if operation not in switch:
+            return
+        switch[operation](file)
+
+    @classmethod
+    def shift_left(cls, _) -> None:
+        Memory.pointer -= 1
+    
+    @classmethod
+    def shift_right(cls, _) -> None:
+        Memory.pointer += 1
+
+    @classmethod    
+    def increment(cls, _) -> None:
+        Memory.buffer[Memory.get_pointer()] += 1
+
+    @classmethod
+    def decrement(cls, _) -> None:
+        Memory.buffer[Memory.get_pointer()] -= 1
+
+    @classmethod
+    def output(cls, _) -> None:
+        print(chr(Memory.buffer[Memory.get_pointer()]), end="") # TODO rollover if too big in ASCII
+
+    @classmethod
+    def input(cls, _) -> None:
+        with cls.terminal.cbreak():
+            Memory.buffer[Memory.get_pointer()] = ord(cls.terminal.inkey())
+
+    @classmethod
+    def open_loop(cls, file: TextIOWrapper) -> None:
+        if not Memory.buffer[Memory.get_pointer()]:
+            while True:
+                operation = file.read(1)
+                if operation == Operation.CLOSE_LOOP:
+                    break
+                elif not operation:
+                    raise MismatchBracketException
+        else:
+            cls.loop_stack.append(file.tell()-1)
+    
+    @classmethod
+    def close_loop(cls, file: TextIOWrapper) -> None:
+        if not len(cls.loop_stack):
+            raise MismatchBracketException
+
+        last_open_loop_pos = cls.loop_stack.pop()
+        if Memory.buffer[Memory.get_pointer()]:
+            file.seek(last_open_loop_pos, 0)
+
 def main() -> None:
-    # get bf file location
     file_location = None
     if len(sys.argv) != 2:
         print("Invalid or missing arguments...")
@@ -34,52 +100,16 @@ def main() -> None:
     else:
         file_location = sys.argv[1]
 
-    # open file
     file = open(file_location, "r")
     while True:
         operation = file.read(1)
         if not operation:
             break
-        
-        # perform operation
-        perform_operation(operation, file)
+        Operation.perform(operation, file)
 
     file.close()
-
-def perform_operation(operation: str, file: TextIOWrapper) -> None:
-    if operation == Operation.SHIFT_LEFT:
-        Memory.pointer -= 1
-    elif operation == Operation.SHIFT_RIGHT:
-        Memory.pointer += 1
-    elif operation == Operation.INCREMENT:
-        Memory.buffer[Memory.get_pointer()] += 1
-    elif operation == Operation.DECREMENT:
-        Memory.buffer[Memory.get_pointer()] -= 1
-    elif operation == Operation.OUTPUT:
-        print(chr(Memory.buffer[Memory.get_pointer()]), end="")
-    elif operation == Operation.INPUT:
-        term = Terminal()
-        with term.cbreak():
-            Memory.buffer[Memory.get_pointer()] = ord(term.inkey())
-    elif operation == Operation.OPEN_LOOP:
-        if Memory.buffer[Memory.get_pointer()] == 0:
-            while True:
-                operation = file.read(1)
-                if operation == Operation.CLOSE_LOOP:
-                    break
-                elif not operation:
-                    print("Mismatched bracket...") # TODO add line number and column on line
-                    sys.exit()
-        else:
-            Memory.loop_stack.append(file.tell()-1)
-    elif operation == Operation.CLOSE_LOOP:
-        if len(Memory.loop_stack) == 0:
-            print("Mismatched bracket...") # TODO add line number and column on line
-            sys.exit()
-            
-        open_loop_position = Memory.loop_stack.pop()
-        if Memory.buffer[Memory.get_pointer()] != 0:
-            file.seek(open_loop_position, 0)
+    if len(Operation.loop_stack):
+        raise MismatchBracketException
 
 if __name__ == "__main__":
     main()