# Sprint 54 Plan: Homoiconic and AST-Native Family (Lisp, Scheme, Elisp, Smalltalk)

## Context

These languages are AST-friendly but carry macro/eval/message semantics that can
still break naive projection. Sprint 54 treats them as first-class paradigm targets.

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## Goals

1. Build canonical S-expression/message-send lowering model
2. Preserve macro intent and expansion boundaries in IR
3. Add Smalltalk object/message semantics adapter
4. Validate claim that AST-native authoring projects with low friction

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## Steps

### Step 769: S-expression canonical lowering layer (12 tests)
### Step 770: Lisp lowering/raising adapters (10 tests)
### Step 771: Scheme lowering/raising adapters (10 tests)
### Step 772: Elisp lowering/raising adapters (10 tests)
### Step 773: Smalltalk lowering/raising adapters (10 tests)
### Step 774: Macro boundary + hygienic expansion packet model (10 tests)
### Step 775: Eval/runtime boundary risk model (8 tests)
### Step 776: `whetstone_transpile_ast_native_family` MCP tool (8 tests)
### Step 777: AST-native projection benchmark suite (8 tests)
### Step 778: Sprint 54 integration summary + regression (8 tests)

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## Success Signal

- AST-native authored corpus should achieve highest equivalence confidence and
  lowest review-required rate among all families.