Create 20. Own programming language, Part 3: Jump command

Week 7 Libraries and More Python/20. Own programming language, Part 3: Jump command

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+'''Jump command
+
+Implement the function
+execute(code: str) -> str
+in addition to the properties of the previous functions, the following additional commands:
+
+
+LABEL location
+The command adds the named location to the code. 
+The command does not by itself cause any changes in the code execution. 
+The given location may be any STRING of letters and numbers.
+
+GOTO place
+Code execution continues from the given named location. 
+The location must be named by the LABEL instruction. 
+The location may be in the code before or after the jump instruction. 
+The program need not worry about possible eternal loops, this is left to the programmer. 
+
+
+
+Example programs for testing instructions:
+
+Program:
+LET a=29
+GOTO end
+INC a 10  # SKIP THIS LINE
+INC a 20 # SKIP THIS LINE
+
+LABEL end
+PRINT a
+The program returns the printout:
+29
+
+
+
+
+
+
+
+Program:
+LET a=88
+GOTO point1
+INC a 10 # SKIP THIS LINE
+INC a 20 # SKIP THIS LINE
+
+LABEL point1
+PRINT a
+
+GOTO per2
+DEC a 20 # SKIP THIS LINE
+DEC a 30 # SKIP THIS LINE
+
+LABEL per2
+PRINT a
+The program returns the result:
+88
+88
+
+
+
+
+
+
+
+Program:
+GOTO point1
+
+LABEL point3 # from below
+PRINT a
+GOTO end # go to 'end' on the last line
+
+LABEL point2 # from below
+DEC a 10
+GOTO point3 # go up to point3
+
+LABEL point1 # From line 1
+LET a=53
+GOTO point2 # them go up to point2
+
+LABEL end # from above
+
+The program returns the result:
+43
+
+'''
+
+
+
+
+
+
+
+def execute(code: str) -> str:
+    variables = {'a': 0, 'b': 0, 'c': 0, 'd': 0}
+    output = []
+
+    ###################
+    # Refactored for this exercise to keep track of line number for LABEL 
+    ###################
+    # Split the code into lines and strip whitespace
+    lines = [line.strip() for line in code.split('\n')]
+    
+    # Track labels and their corresponding line numbers
+    labels = {}
+    for i, line in enumerate(lines):
+        if line.startswith('LABEL'):
+            _, location = line.split()
+            labels[location] = i  # Store the line number of the label
+
+
+    i = 0
+    while i < len(lines):
+        line = lines[i]
+        
+        # Skip empty lines
+        if not line:
+            i += 1
+            continue
+        ###################
+
+        
+        if line.startswith('LET'):
+            _, assignment = line.split(' ', 1)
+            var, value = assignment.split('=')
+            if var in variables:
+                variables[var] = int(value)
+                i += 1
+            else:
+                raise ValueError(f"Invalid variable name: {var}")
+        elif line.startswith('PRINT'):
+            _, var = line.split()
+            if var in variables:
+                output.append(str(variables[var]))
+                i += 1
+            else:
+                raise ValueError(f"Undefined variable: {var}")
+
+
+
+
+        ##########################################
+        # 19. part 2
+        ##########################################
+        elif line.startswith('INC') or line.startswith('DEC'):
+            # Handle INC and DEC commands
+            parts = line.split()
+            command = parts[0]
+            var1 = parts[1]
+            
+            if var1 not in variables:
+                raise ValueError(f"Invalid variable name: {var1}")
+
+
+
+
+            if len(parts) == 3:
+                # Check if parts[2] is an integer
+                try:
+                    value = int(parts[2])  # Try to convert parts[2] to an integer
+                    
+                    # If conversion succeeds
+                    # INC/DEC variable number
+                    if command == 'INC':
+                        variables[var1] += value
+                    elif command == 'DEC':
+                        variables[var1] -= value
+                    i += 1
+
+
+
+                        
+                # parts[2] is NOT an integer
+                except ValueError:
+                    # INC/DEC variable1 variable2
+                    var2 = parts[2]
+                    if var2 not in variables:
+                        raise ValueError(f"Invalid variable name: {var2}")
+                    
+                    if command == 'INC':
+                        variables[var1] += variables[var2]
+                    elif command == 'DEC':
+                        variables[var1] -= variables[var2]  
+                    i += 1
+            
+            else:
+                raise ValueError(f"Invalid command format: {line}")
+        ##########################################
+
+
+
+
+        ##########################################
+        # 20. part 3
+        ##########################################
+        elif line.startswith('LABEL'):
+            # Labels are already processed, so just 'skip' the line
+            i += 1
+        
+        elif line.startswith('GOTO'):
+            _, location = line.split()
+            if location in labels:
+                i = labels[location]  # Jump to the line number of the label
+            else:
+                raise ValueError(f"Undefined label: {location}")
+        ##########################################
+
+        
+        else:
+            raise ValueError(f"Invalid command: {line}")
+
+            
+
+    
+    joined_output = '\n'.join(output)
+    joined_output+='\n'
+    return joined_output
+
+
+
+
+
+eg1='''LET a=29
+GOTO end
+INC a 10
+INC a 20
+LABEL end
+PRINT a'''
+
+print(execute(eg1))
+
+
+
+
+
+
+eg2='''LET a=88
+GOTO point1
+INC a 10
+INC a 20
+LABEL point1
+PRINT a
+GOTO per2
+DEC a 20
+DEC a 30
+LABEL per2
+PRINT a'''
+
+print(execute(eg2))
+
+
+
+
+eg3='''GOTO point1
+LABEL point3
+PRINT a
+GOTO end
+LABEL point2
+DEC a 10
+GOTO point3
+LABEL point1
+LET a=53
+GOTO point2
+LABEL end'''
+
+print(execute(eg3))
+
+
+
+
+
+
+
+