Execute Computer/Zero: Difference between revisions

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@@ Line 647: / Line 647: @@
 =={{header|Python}}==
 <lang python>"""Computer/zero Assembly emulator. Requires Python >= 3.7"""
+import re
 from typing import Dict
 from typing import Iterable
@@ Line 653: / Line 656: @@
 from typing import Optional
 from typing import Tuple
-from typing import Union
@@ Line 676: / Line 678: @@
 }
+RE_INSTRUCTION = re.compile(
+    r"\s*"
+    r"(?:(?P<label>\w+):)?"
+    r"\s*"
+    rf"(?P<opcode>{'|'.join(OPCODES)})?"
+    r"\s*"
+    r"(?P<argument>\w+)?"
+    r"\s*"
+    r"(?:;(?P<comment>[\w\s]+))?"
+)
-class Instruction(NamedTuple):
-    opcode: Optional[str]
-    argument: Union[str, int, None]
+class AssemblySyntaxError(Exception):
+    pass
-Bytecode = Iterable[int]
-Instructions = List[Instruction]
-Labels = Dict[str, int]
+class Instruction(NamedTuple):
+    label: Optional[str]
+    opcode: Optional[str]
+    argument: Optional[str]
+    comment: Optional[str]
-def parse(assembly: str) -> Tuple[Instructions, Labels]:
+def parse(assembly: str) -> Tuple[List[Instruction], Dict[str, int]]:
-    instructions: Instructions = []
+    instructions: List[Instruction] = []
     labels: Dict[str, int] = {}
     linenum: int = 0
-    lines = [line.strip() for line in assembly.split("\n")]
-    for line in lines:
+    for line in assembly.split("\n"):
-        # Discard comments
+        match = RE_INSTRUCTION.match(line)
-        if ";" in line:
-            line = line.split(";", 1)[0]
+        if not match:
+            raise AssemblySyntaxError(f"{line}: {linenum}")
+        instructions.append(Instruction(**match.groupdict()))
-        # Parse label
-        if ":" in line:
+        label = match.group(1)
-            label, line = line.split(":", 1)
+        if label:
             labels[label] = linenum
-        # Parse opcode and argument
-        instruction = line.strip().split()
-        if len(instruction) == 1:
-            if instruction[0] in OPCODES:
-                # Opcode without argument
-                opcode: Optional[str] = instruction[0]
-                argument: Union[str, int, None] = None
-            elif instruction[0].isnumeric():
-                # Data, without opcode
-                opcode = None
-                argument = int(instruction[0])
-            else:
-                # Unexpected
-                raise Exception(f"unknown instruction '{line}', {linenum}")
-        elif len(instruction) == 2:
-            # Opcode and argument
-            opcode, argument = instruction
-            if opcode not in OPCODES:
-                raise Exception(f"unknown instruction '{line}', {linenum}")
-            if argument.isnumeric():
-                argument = int(argument)
-            else:
-                # Argument is a label
-                argument = argument
-        elif not instruction:
-            # blank line
-            opcode = "NOP"
-            argument = None
-        else:
-            raise Exception(f"unknown instruction '{line}', {linenum}")
-        instructions.append(Instruction(opcode, argument))
         linenum += 1
@@ Line 742: / Line 722: @@
-def compile(instructions: Instructions, labels: Labels) -> Bytecode:
+def compile(instructions: List[Instruction], labels: Dict[str, int]) -> Iterable[int]:
     for instruction in instructions:
-        if isinstance(instruction.argument, str):
+        if instruction.argument is None:
-            argument = labels[instruction.argument]
-        elif isinstance(instruction.argument, int):
-            argument = instruction.argument
-        else:
             argument = 0
+        elif instruction.argument.isnumeric():
+            argument = int(instruction.argument)
+        else:
+            argument = labels[instruction.argument]
         if instruction.opcode:
@@ Line 785: / Line 765: @@
             break
         else:
-            raise Exception(":( " + str(operation))
+            raise Exception(f"error: {operation} {argument}")
     return accumulator
@@ Line 928: / Line 908: @@
 def main() -> None:
     for sample in SAMPLES:
-        instructions, labels = parse(sample.strip())
+        instructions, labels = parse(sample)
         bytecode = bytes(compile(instructions, labels))
-        # print(bytecode)
+        result = run(bytecode)
-        print(run(bytecode))
+        print(result)