feat(runner): implement simple REPL

main.py

@@ -1,11 +1,8 @@
-from pathlib import Path
-
-from src.pebble import Pebble
+from src.runner import Runner
 
 
 def main():
-    path: Path = Path("examples/advanced/02_polymorphism.peb")
-    Pebble.run_file(path)
+    Runner.repl()
 
 
 if __name__ == '__main__':

src/runner.py

@@ -7,7 +7,7 @@ from src.interpreter.resolver import Resolver
 from src.lexer import Lexer
 from src.parser.parser import Parser
 from src.pebble import Pebble
-from src.token import Token
+from src.token import Token, TokenType
 
 
 class Runner:
@@ -43,3 +43,71 @@ class Runner:
         formatter: Formatter = Formatter()
         with open("formatted.peb", "w") as f:
             f.write(formatter.print(program))
+
+    @staticmethod
+    def repl():
+        line: str
+        lexer: Lexer
+        tokens: list[Token]
+        parser: Parser
+        program: list[Stmt]
+        interpreter: Interpreter = Interpreter()
+        resolver: Resolver
+
+        brace_depth: int
+        paren_depth: int
+        buf: str = ""
+        while True:
+            try:
+                line = input(">>> " if len(buf) == 0 else "... ")
+            except EOFError:
+                print()
+                break
+            except KeyboardInterrupt:
+                buf = ""
+                print()
+                continue
+
+            buf += line + "\n"
+            lexer = Lexer(buf)
+            tokens = lexer.process()
+            if Pebble.had_error:
+                Pebble.had_error = False
+                continue
+
+
+            brace_depth = 0
+            paren_depth = 0
+            for token in tokens:
+                match token.type:
+                    case TokenType.LEFT_BRACE:
+                        brace_depth += 1
+                    case TokenType.RIGHT_BRACE:
+                        brace_depth = max(0, brace_depth - 1)
+                    case TokenType.LEFT_PAREN:
+                        paren_depth += 1
+                    case TokenType.RIGHT_PAREN:
+                        paren_depth = max(0, paren_depth - 1)
+
+            if brace_depth > 0 or paren_depth > 0:
+                continue
+
+            parser = Parser(tokens)
+            program = parser.parse()
+            buf = ""
+
+            if Pebble.had_error:
+                Pebble.had_error = False
+                continue
+
+            resolver: Resolver = Resolver(interpreter)
+
+            resolver.resolve(*program)
+            if Pebble.had_error:
+                Pebble.had_error = False
+                continue
+            interpreter.interpret(program)
+
+            if Pebble.had_runtime_error:
+                Pebble.had_runtime_error = False
+                continue