Mellea Fy Map

Melleafy Step 2: Element-to-Primitive Mapping

Version: 4.1.0 | Prereq: inventory.json, classification.json | Produces: element_mapping.json

Schema: Output intermediate/element_mapping.json MUST conform to schemas/element_mapping.schema.json.

Step 2 reads inventory.json and produces element_mapping.json — the routing decision for every element: which file in the generated package, which symbol, which Mellea primitive.

Important: Step 2 does NOT commit dispositions for tool-dependent elements. Every TOOL_TEMPLATE mapping entry is provisional (final_target_file: "pending_step_2.5"). Step 2.5 decides real_impl vs stub vs mock and amends.

Tag-to-primitive table

Alternative rules

EXTRACT — one-step vs two-step pattern

Default: one @generative slot returning the target schema.

Two-step pattern applies when any of:

• Target schema has cross-reference fields (a field that references another field's value in the same document)
• Target schema has more than 3 levels of nesting
• Target schema has optional fields whose presence depends on earlier fields' values
• Target schema has more than 4 fields OR contains Literal constraints OR has nested BaseModel objects OR lists of complex objects

When two-step applies, produce two mapping entries sharing the same element_id (suffixed -step1, -step2):

1. @generative slot returning a simplified flat structure (slots.py:extract_X_raw)
2. m.instruct(format=FullSchema, strategy=RepairTemplateStrategy(loop_budget=3)) inline in pipeline.py

The reason: @generative has no retry/repair mechanism — malformed JSON silently returns empty. m.instruct(format=...) with RepairTemplateStrategy retries and repairs.

VALIDATE_OUTPUT — executable vs LLM-judged

Default: Requirement with executable validation_fn (structural check in plain Python).

LLM-judged (bare Requirement(description=...)) only when content_full contains words like "accurate," "appropriate," "reasonable," "matches the spirit of" — markers of semantic judgement that can't be expressed in Python.

Record the choice as validation_kind: "executable" | "llm_judged" in the mapping entry.

CONVERSE — three realisations

1. m.chat() — LLM self-talk: when the source describes multi-turn reasoning within the pipeline ("consider counterarguments then respond"). Emitted inline in pipeline.py.
2. Pipeline parameter with default: when the source says "ask the user for X." X becomes a parameter on run_pipeline with a default, exposed as a CLI flag on main.py.
3. NotImplementedError stub: when the source describes genuine interactive back-and-forth that can't be reshaped into either above — e.g., "iterate with the user until they approve the output." SETUP.md §7 explains the host-adapter requirement.

Decision rule: pick (2) when content_full contains "ask the user" or "user provides"; (1) when phrasing is about the agent's own reasoning ("consider," "reflect"); (3) when neither fits. If classification.json:modality == "conversational_session", prefer (1).

REMEDIATE — loop structure

Three mapping entries for one source element:

1. Modification step — m.instruct(format=PatchSchema) producing a fix
2. Evaluation step — m.instruct(format=VerdictSchema) checking whether the fix worked
3. Loop wrapper — plain Python while i < MAX_REMEDIATION_ITERATIONS tying them together

All three route to pipeline.py. MAX_REMEDIATION_ITERATIONS is always a config.py constant with default 3.

TOOL_TEMPLATE — provisional file routing

Step 2 always routes TOOL_TEMPLATE to tools.py initially. Step 2.5d amends based on disposition:

• real_impl → stays in tools.py
• stub or delegate_to_runtime → moved to constrained_slots.py
• mock → moved to fixtures/mock_tools.py

Record final_target_file: "pending_step_2.5" in the mapping entry until Step 2.5d runs.

Dialect-specific overrides

The dialect mapping table in docs/dialects/<runtime>.md takes precedence over the general table above.

Precedence (highest first):

1. Dialect doc's mapping table (source-signal-specific rows)
2. Alternative rules above (tag-specific cases)
3. General tag-to-primitive table (the default)

Record every dialect override with dialect_override_applied: "<runtime>:<row>" in the mapping entry.

When LLM judgement is invoked

Step 2 is mechanical wherever possible. LLM invocation is bounded to specific narrowly-scoped decisions:

• VALIDATE_OUTPUT semantic-vs-executable classification when phrase-match heuristic is inconclusive
• CONVERSE realisation selection when element phrasing doesn't match the three rules
• DETERMINISTIC placement when length is borderline and call graph is unclear
• EXTRACT two-step eligibility in rare cases where schema analysis is ambiguous

Parallelization strategy: Instead of issuing one LLM invocation per element requiring judgment, collect all judgment-requiring elements in a single pass, then dispatch all judgment calls in parallel (all at once in a single turn using tool-call parallelism). Each judgment call invocation is scoped to a single element; all such invocations can proceed independently since they share no dependencies.

After all parallel judgment calls complete, merge their results back into the mapping entries before finalising element_mapping.json.

Output goes into intermediate/element_mapping_judgment_calls.json.

Output: element_mapping.json

{
  "mapping_id": "map_001",
  "element_id": "elem_042",
  "target_file": "pipeline.py",
  "target_symbol": "run_pipeline",
  "primitive": "m.instruct",
  "primitive_details": {
    "format_schema": "TriageVerdict",
    "grounding_context_keys": ["ticket_text", "operating_rules"]
  },
  "final_target_file": "pipeline.py",
  "step_2_confidence": 0.9,
  "step_2_rationale": "DECIDE tag with clear enum output → m.instruct with format=DecisionSchema",
  "llm_judgement_required": false,
  "dialect_override_applied": null,
  "validation_kind": null
}

Cross-checks before Step 2 declares done:

• Count of mapping entries equals count of inventory entries (plus expansions for two-step and remediation)
• Every NO_DECOMPOSE element has a mapping entry with primitive: "none"
• No mapping entry has empty target_file or target_symbol (except NO_DECOMPOSE)
• Every target_file named is in the shape doc's always-emitted list or a conditional file whose trigger is predicted to fire
• Every dialect_override_applied non-null value references a real row in the detected runtime's dialect doc

Failure at any check is a generation-halt error. .melleafy-partial/ retains the intermediate artifacts for debugging.