whetstone_DSL/sprint47_plan.md

Sprint 47 Plan: Rust Semantic Lowering to Core IR

Context

Sprint 47 makes Rust the first full-fidelity source language for the new semantic core. This sprint focuses on lowering correctness: ownership/borrowing, traits, error semantics, async semantics, and macro boundary behavior.

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Goals

1. Lower real Rust constructs into SemanticCoreIR
2. Build ownership and borrow-region graph extraction
3. Capture trait and generics semantics in IR
4. Emit review packets for unsupported/unsafe regions

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Steps

Step 699: Rust ownership/borrow graph extractor (12 tests)

Step 700: Lifetime region lowering (10 tests)

Step 701: Trait + impl lowering (10 tests)

Step 702: Generic/monomorphization intent model (10 tests)

Step 703: Error model lowering (Result, Option, panic) (10 tests)

Step 704: Async/await state intent lowering (10 tests)

Step 705: Macro boundary capture + fallback policy (8 tests)

Step 706: Unsafe block risk packet generator (8 tests)

Step 707: whetstone_analyze_rust_semantics MCP tool (8 tests)

Step 708: Sprint 47 integration summary + regression (8 tests)

For each step above:

• Create/extend modules under editor/src/rust_ir/
• Add deterministic JSON packets for downstream C++ raising
• Attach confidence + review-required tags at lowering time

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Verification Focus

• Rust sample corpus must cover: ownership transfer, borrowing, lifetimes, traits, generics, async, unsafe, macro usage
• Unsupported features must fail closed with actionable diagnostics
• No silent semantic drop allowed