feat(lexer): add strings

main.py

@@ -4,7 +4,10 @@ from src.token import Token
 
 def main():
     source: str = """()  {}  +- += / /= // sefs + {, )
-    }:: *"""
+    }:: *
+    "This is a string"
+    "This is
+     another string" """
     lexer: Lexer = Lexer()
     tokens: list[Token] = lexer.process(source)
     print(tokens)

src/lexer.py

@@ -16,6 +16,9 @@ class Lexer:
         self.column: int = 0
         self.start_pos: Position = self.get_position()
 
+    def error(self, msg: str):
+        raise SyntaxError(f"[ERROR] Error at {self.start_pos}: {msg}")
+
     def process(self, source: str, path: Optional[str] = None) -> list[Token]:
         self.path = path or "<main>"
         self.source = source
@@ -116,10 +119,22 @@ class Lexer:
                 while self.peek().isspace() and not self.is_at_end():
                     self.advance()
                 self.add_token(TokenType.WHITESPACE)
+            case '"':
+                self.scan_string()
             case _:
                 self.error("Unexpected character")
-
         return None
 
-    def error(self, msg: str):
-        raise SyntaxError(f"[ERROR] Error at {self.start_pos}: {msg}")
+    def scan_string(self):
+        while self.peek() != '"' and not self.is_at_end():
+            if self.peek() == "\n":
+                self.line += 1
+                self.column = 0
+            self.advance()
+
+        if self.is_at_end():
+            self.error("Unterminated string")
+
+        self.advance()
+        value: str = self.source[self.start + 1:self.idx - 1]
+        self.add_token(TokenType.STRING, value)

src/token.py

@@ -70,6 +70,6 @@ class Token:
     def __repr__(self) -> str:
         res: str = f"[{self.type.name}"
         if self.value is not None:
-            res += f" ({self.value})"
+            res += f" ({self.value!r})"
         res += "]"
         return res