Renaming:

ctx.as_list(last_n_components..)

ctx.render_for_generation() -->
ctx.view_for_generation()

Author: HendrikStrobelt

mellea/backends/huggingface.py

@@ -239,7 +239,7 @@ def _generate_from_context_alora(
                     "This code block should not execute unless there is a 'constraint' alora loaded."
                 )
         # Construct the linearized context. This is very similar to normal generation.
-        linearized_ctx = ctx.render_for_generation()
+        linearized_ctx = ctx.view_for_generation()
         assert linearized_ctx is not None and len(linearized_ctx) > 1
         msgs = self.formatter.to_chat_messages(linearized_ctx)
         user_message, assistant_message = msgs[-2].content, msgs[-1].content
@@ -278,7 +278,7 @@ def _generate_from_context_standard(
         # If the Context is a ChatHistory then we will pretty-print each content as a message and then use apply_chat_template.
         # Otherwise, we will linearize the context and treat it as a raw input.
         if ctx.is_chat_context:
-            linearized_ctx = ctx.render_for_generation()
+            linearized_ctx = ctx.view_for_generation()
             assert linearized_ctx is not None, (
                 "If ctx.is_chat_context, then the context should be linearizable."
             )

mellea/backends/litellm.py

@@ -217,7 +217,7 @@ def _generate_from_chat_context_standard(
         tool_calls: bool = False,
     ) -> ModelOutputThunk:
         model_opts = self._simplify_and_merge(model_options)
-        linearized_context = ctx.render_for_generation()
+        linearized_context = ctx.view_for_generation()
         assert linearized_context is not None, (
             "Cannot generate from a non-linear context in a FormatterBackend."
         )

mellea/backends/ollama.py

@@ -273,7 +273,7 @@ def generate_from_chat_context(
         """
         model_opts = self._simplify_and_merge(model_options)
 
-        linearized_context = ctx.render_for_generation()
+        linearized_context = ctx.view_for_generation()
         assert linearized_context is not None, (
             "Cannot generate from a non-linear context in a FormatterBackend."
         )

mellea/backends/openai.py

@@ -342,7 +342,7 @@ def _generate_from_chat_context_alora(
                 )
 
         # Construct the linearized context. This is very similar to normal generation.
-        linearized_ctx = ctx.render_for_generation()
+        linearized_ctx = ctx.view_for_generation()
         assert linearized_ctx is not None and len(linearized_ctx) > 1
         msgs = self.formatter.to_chat_messages(linearized_ctx)
         user_message, assistant_message = msgs[-2].content, msgs[-1].content
@@ -417,7 +417,7 @@ def _generate_from_chat_context_standard(
         model_opts = self._simplify_and_merge(
             model_options, is_chat_context=ctx.is_chat_context
         )
-        linearized_context = ctx.render_for_generation()
+        linearized_context = ctx.view_for_generation()
         assert linearized_context is not None, (
             "Cannot generate from a non-linear context in a FormatterBackend."
         )

mellea/backends/watsonx.py

@@ -242,7 +242,7 @@ def generate_from_chat_context(
             model_options, is_chat_context=ctx.is_chat_context
         )
 
-        linearized_context = ctx.render_for_generation()
+        linearized_context = ctx.view_for_generation()
         assert linearized_context is not None, (
             "Cannot generate from a non-linear context in a FormatterBackend."
         )

mellea/stdlib/base.py

@@ -348,15 +348,18 @@ class ContextTurn:
 
 
 class Context(abc.ABC):
-    """A `Context` is used to track the state of a `MelleaSession`."""
+    """A `Context` is used to track the state of a `MelleaSession`.
+
+    A context is immutable. Every alteration leads to a new context.
+    """
 
     _previous: Context | None
     _data: Component | CBlock | None
     _is_root: bool
     _is_chat_context: bool = True
 
     def __init__(self):
-        """Constructs a new context."""
+        """Constructs a new root context with no content."""
         self._previous = None
         self._data = None
         self._is_root = True
@@ -403,18 +406,24 @@ def data(self) -> Component | CBlock | None:
         """Returns the data associated with this context."""
         return self._data
 
-    def full_data_as_list(self) -> list[Component | CBlock]:
-        """Returns a list of all components in the context from root to current context."""
+    def as_list(self, last_n_components: int | None = None) -> list[Component | CBlock]:
+        """Returns a list of the last n components in the context sorted from FIRST TO LAST.
+
+        If `last_n_elements` is `None`, then all components are returned."""
         context_list: list[Component | CBlock] = []
         current_context: Context = self
 
-        while not current_context.is_root:
+        last_n_count = 0
+        while not current_context.is_root and (
+            last_n_components is None or last_n_count < last_n_components
+        ):
             data = current_context.data
             assert data is not None, "Data cannot be None (except for root context)."
             assert data not in context_list, (
                 "There might be a cycle in the context tree. That is not allowed."
             )
             context_list.append(data)
+            last_n_count += 1
 
             current_context = current_context.previous  # type: ignore
             assert current_context is not None, (
@@ -429,20 +438,20 @@ def actions_for_available_tools(self) -> list[Component | CBlock] | None:
 
         Can be used to make the available tools differ from the tools of all the actions in the context. Can be overwritten by subclasses.
         """
-        return self.render_for_generation()
+        return self.view_for_generation()
 
     def last_output(self) -> ModelOutputThunk | None:
         """The last output thunk of the context."""
 
-        for c in self.full_data_as_list()[::-1]:
+        for c in self.as_list()[::-1]:
             if isinstance(c, ModelOutputThunk):
                 return c
         return None
 
     def last_turn(self):
         """The last input/output turn of the context."""
 
-        history = self.full_data_as_list()
+        history = self.as_list()
 
         if len(history) == 0:
             return None
@@ -467,7 +476,7 @@ def add(self, c: Component | CBlock) -> Context:
         ...
 
     @abc.abstractmethod
-    def render_for_generation(self) -> list[Component | CBlock] | None:
+    def view_for_generation(self) -> list[Component | CBlock] | None:
         """Provides a linear list of context components to use for generation, or None if that is not possible to construct."""
         ...
 
@@ -480,26 +489,22 @@ def __init__(self, *, window_size: int | None = None):
         super().__init__()
         self._window_size = window_size
 
-    def render_for_generation(self) -> list[Component | CBlock] | None:
-        all_events = self.full_data_as_list()
-        ws = self._window_size
-        ws = ws if ws is not None else len(all_events)
-
-        return all_events[-ws:]
-
     def add(self, c: Component | CBlock) -> ChatContext:
         new = ChatContext.from_previous(self, c)
         new._window_size = self._window_size
         return new
 
+    def view_for_generation(self) -> list[Component | CBlock] | None:
+        return self.as_list(self._window_size)
+
 
 class SimpleContext(Context):
     """A `SimpleContext` is a context in which each interaction is a separate and independent turn. The history of all previous turns is NOT saved.."""
 
     def add(self, c: Component | CBlock) -> SimpleContext:
         return SimpleContext.from_previous(self, c)
 
-    def render_for_generation(self) -> list[Component | CBlock] | None:
+    def view_for_generation(self) -> list[Component | CBlock] | None:
         return []
 
 

mellea/stdlib/chat.py

@@ -129,7 +129,7 @@ def _to_msg(c: CBlock | Component | ModelOutputThunk) -> Message | None:
             case _:
                 return None
 
-    all_ctx_events = ctx.full_data_as_list()
+    all_ctx_events = ctx.as_list()
     if all_ctx_events is None:
         raise Exception("Trying to cast a non-linear history into a chat history.")
     else: