core-logic-planner

name	core-logic-planner
description	Domain guidance for planning core logic and algorithm phases. Loaded when phase category is CORE.

Core Logic Planning Guidance

Scope the logic surface

• Define inputs, outputs, invariants, and failure behavior for each function.
• Mark functions as PURE (no mutation, no I/O) or STATEFUL (explicit state object). Agents default to mutation unless told otherwise.

Edge cases are planner-owned

Enumerate explicitly — do not delegate discovery to the executor:

• Numeric: 0, 1, -1, min/max bounds, overflow if applicable.
• Collections: empty, single-element, duplicates, already-sorted/reversed.
• Nullable: None/null, missing keys, empty strings, whitespace.

State machines: plan must be complete

Provide a transition table: current_state × event → next_state + outputs. Call out illegal transitions and expected error behavior. Incomplete tables cause executor guesswork.

Pass criteria for logic completeness

• All branches in conditionals are exercised by tests.
• Match/switch is exhaustive (explicit default or compiler-checked).
• Illegal states are rejected deterministically.
• "Done" = all pass criteria met + no extra APIs/abstractions beyond plan.

Prevent over-engineering

• "No new abstractions unless required by pass criteria."
• "No generalization beyond documented cases."
• "Minimize diff: touch only specified files."
• Add complexity budget if relevant (expected big-O, performance guardrails).