Implemented by both AstNode and ContextState, so anything that
needs "give me the prompt" can take impl Ast.
Co-Authored-By: Proof of Concept <poc@bcachefs.org>
Role is now just System/User/Assistant — maps 1:1 to the grammar.
Leaf types are NodeBody variants: Content, Thinking, ToolCall,
ToolResult, Memory, Dmn, Log. Each variant renders itself; no Role
needed on leaves. AstNode is Leaf(NodeLeaf) | Branch{role, children}.
ContextState holds four Vec<AstNode> sections directly.
Moved tool call XML parsing from api/parsing.rs into context_new.rs
so all grammar knowledge lives in one place.
Tokenizer encode() now returns empty vec when uninitialized instead
of panicking, so tests work without the tokenizer file.
26 tests: XML parsing, incremental streaming (char-by-char feeds
found and fixed a lookahead bug), rendering for all node types,
tokenizer round-trip verification.
Co-Authored-By: Proof of Concept <poc@bcachefs.org>
AstNode fields are now private with read-only accessors. All mutation
goes through ContextState methods (push, set_message, set_score, del)
which guarantee token_ids stays in sync with text on every leaf.
Also fix ResponseParser to use AstNode::tool_call() constructor,
widen parsing module visibility to pub(crate).
Co-Authored-By: Proof of Concept <poc@bcachefs.org>
New context_new.rs with the AST-based context window design:
- AstNode: role + NodeBody (Leaf with text+token_ids, or Branch with children)
- Tokens only on leaves, branches walk children
- render() produces UTF-8, tokenize produces token IDs, same path
- ResponseParser state machine for streaming assistant responses
- Role enum covers all node types including sections
Still needs: fix remaining pattern match issues, add ContextState wrapper,
wire into mod.rs, replace old context.rs.
Does not compile yet — this is a design checkpoint.
Co-Authored-By: Proof of Concept <poc@bcachefs.org>
