diff --git a/loglens/formatters/base.py b/loglens/formatters/base.py
index c7debd7..b7063ba 100644
--- a/loglens/formatters/base.py
+++ b/loglens/formatters/base.py
@@ -1,13 +1,28 @@
+"""Base formatter class."""
+
 from abc import ABC, abstractmethod
-from typing import Any
-
-from loglens.analyzers.analyzer import AnalysisResult
+from typing import Any, Optional, TextIO
 
 
-class Formatter(ABC):
-    """Base formatter class."""
+class OutputFormatter(ABC):
+    """Abstract base class for output formatters."""
+
+    def __init__(self, output: Optional[TextIO] = None):
+        self.output = output
 
     @abstractmethod
-    def format(self, result: AnalysisResult) -> str:
-        """Format the analysis result."""
+    def format(self, data: Any) -> str:
+        """Format data for output."""
         pass
+
+    def write(self, text: str) -> None:
+        """Write to output stream."""
+        if self.output:
+            self.output.write(text)
+        else:
+            print(text, end="")
+
+    def flush(self) -> None:
+        """Flush output stream."""
+        if self.output:
+            self.output.flush()