feat(normalization): Phase 142 P0 - Statement-level normalization

## Summary

Changed normalization unit from "block suffix" to "statement (loop only)"
to prevent pattern explosion.

## Changes

1. **PlanBox** (`plan_box.rs`):
   - Always return `loop_only()` for any `loop(true)`, regardless of what follows
   - Subsequent statements (return, assignments) handled by normal MIR lowering
   - ~70 lines reduced, 7 unit tests updated

2. **build_block** (`stmts.rs`):
   - Removed `break` after consumed=1 from suffix_router
   - Continue processing subsequent statements normally
   - Phase 142 P0 comments added

3. **Tests**:
   - Fixture: `phase142_loop_stmt_only_then_return_length_min.hako`
   - VM smoke: exit code 3 (s="abc" → s.length() → 3)

## Results

-  Unit tests: 10/10 passed
-  Phase 142 VM smoke: PASS
-  Phase 131 regression: PASS
-  Build: Success

## Design

- **Pattern Explosion Prevention**: Normalize only the loop (consumed=1)
- **Out-of-Scope Policy**: Always Ok(None) for fallback
- **Fail-Fast**: Only for "in-scope but broken" cases

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
This commit is contained in:
2025-12-19 04:41:01 +09:00
parent 3ef929df53
commit 275fe45ba4
4 changed files with 106 additions and 144 deletions

View File

@ -70,76 +70,17 @@ impl NormalizationPlanBox {
return Ok(None);
}
// Phase 131: Loop-only pattern (single statement)
if remaining.len() == 1 {
if debug {
trace.routing(
"normalization/plan",
func_name,
"Detected Phase 131 pattern: loop-only",
);
}
return Ok(Some(NormalizationPlan::loop_only()));
}
// Phase 132-135: Loop + (assign*) + return
// Count consecutive assignments after the loop
let mut post_assign_count = 0;
for i in 1..remaining.len() {
if matches!(&remaining[i], ASTNode::Assignment { .. }) {
post_assign_count += 1;
} else {
break;
}
}
// After assignments (0 or more), we need a return statement
let return_index = 1 + post_assign_count;
if return_index >= remaining.len() {
// No statement after assignments - not a post pattern
if debug {
trace.routing(
"normalization/plan",
func_name,
&format!(
"No statement after {} assignments, not a valid post pattern",
post_assign_count
),
);
}
// If there's a non-assignment statement after loop but no return, treat as not a pattern
return Ok(None);
}
let has_return = matches!(&remaining[return_index], ASTNode::Return { .. });
if !has_return {
// Statement after loop (and optional assignments) is not return - not a post pattern
if debug {
trace.routing(
"normalization/plan",
func_name,
&format!(
"Statement after loop and {} assignments is not return, not a valid post pattern",
post_assign_count
),
);
}
return Ok(None);
}
// Valid Phase 132-135 pattern: loop + N assignments (N >= 0) + return
// Phase 142 P0: Always return loop_only for loop(true), regardless of what follows
// Normalization unit is now "statement (loop 1個)" not "block suffix"
// Subsequent statements (return, assignments, etc.) handled by normal MIR lowering
if debug {
trace.routing(
"normalization/plan",
func_name,
&format!(
"Detected Phase 132-135 pattern: loop + {} post assigns + return",
post_assign_count
),
"Detected loop(true) - Phase 142 P0: returning loop_only (consumed=1)",
);
}
Ok(Some(NormalizationPlan::loop_with_post(post_assign_count)))
Ok(Some(NormalizationPlan::loop_only()))
}
}
@ -226,9 +167,10 @@ mod tests {
}
#[test]
fn test_plan_block_suffix_phase132_loop_post_single() {
fn test_plan_block_suffix_phase142_loop_with_subsequent_stmts() {
use crate::mir::builder::MirBuilder;
// Phase 142 P0: loop(true) returns loop_only regardless of subsequent statements
let remaining = vec![
make_loop(),
make_assignment("x", 2),
@ -241,15 +183,16 @@ mod tests {
assert!(plan.is_some());
let plan = plan.unwrap();
assert_eq!(plan.consumed, 3); // loop + 1 assign + return
assert_eq!(plan.kind, PlanKind::LoopWithPost { post_assign_count: 1 });
assert!(plan.requires_return);
assert_eq!(plan.consumed, 1); // Phase 142: only consume loop
assert_eq!(plan.kind, PlanKind::LoopOnly);
assert!(!plan.requires_return); // Loop itself doesn't require return
}
#[test]
fn test_plan_block_suffix_phase133_loop_post_multi() {
fn test_plan_block_suffix_phase142_loop_only_always() {
use crate::mir::builder::MirBuilder;
// Phase 142 P0: loop(true) always returns loop_only, even with multiple statements after
let remaining = vec![
make_loop(),
make_assignment("x", 2),
@ -263,32 +206,9 @@ mod tests {
assert!(plan.is_some());
let plan = plan.unwrap();
assert_eq!(plan.consumed, 4); // loop + 2 assigns + return
assert_eq!(plan.kind, PlanKind::LoopWithPost { post_assign_count: 2 });
assert!(plan.requires_return);
}
#[test]
fn test_plan_block_suffix_return_boundary() {
use crate::mir::builder::MirBuilder;
// Pattern with unreachable statement after return
let remaining = vec![
make_loop(),
make_assignment("x", 2),
make_return("x"),
make_assignment("y", 999), // Unreachable
];
let builder = MirBuilder::new();
let plan = NormalizationPlanBox::plan_block_suffix(&builder, &remaining, "test", false)
.expect("Should not error");
assert!(plan.is_some());
let plan = plan.unwrap();
// Should consume only up to return (not the unreachable statement)
assert_eq!(plan.consumed, 3); // loop + 1 assign + return
assert_eq!(plan.kind, PlanKind::LoopWithPost { post_assign_count: 1 });
assert_eq!(plan.consumed, 1); // Phase 142: only consume loop
assert_eq!(plan.kind, PlanKind::LoopOnly);
assert!(!plan.requires_return);
}
#[test]
@ -321,64 +241,25 @@ mod tests {
}
#[test]
fn test_plan_block_suffix_no_match_no_return() {
fn test_plan_block_suffix_phase142_loop_with_trailing_stmt() {
use crate::mir::builder::MirBuilder;
// Phase 142 P0: loop(true) returns loop_only even if no return follows
let remaining = vec![
make_loop(),
make_assignment("x", 2),
// Missing return
];
let builder = MirBuilder::new();
let plan = NormalizationPlanBox::plan_block_suffix(&builder, &remaining, "test", false)
.expect("Should not error");
// No return means not a valid post pattern
assert!(plan.is_none());
}
#[test]
fn test_plan_block_suffix_phase135_loop_return_only() {
use crate::mir::builder::MirBuilder;
// Phase 135: loop + return (0 post assignments)
let remaining = vec![
make_loop(),
make_return("x"),
// No return - but still returns loop_only
];
let builder = MirBuilder::new();
let plan = NormalizationPlanBox::plan_block_suffix(&builder, &remaining, "test", false)
.expect("Should not error");
// Phase 142: loop(true) always matches, regardless of subsequent statements
assert!(plan.is_some());
let plan = plan.unwrap();
assert_eq!(plan.consumed, 2); // loop + return
assert_eq!(plan.kind, PlanKind::LoopWithPost { post_assign_count: 0 });
assert!(plan.requires_return);
}
#[test]
fn test_plan_block_suffix_return_boundary_with_trailing() {
use crate::mir::builder::MirBuilder;
// Pattern with unreachable statement after return (Phase 135 variation)
let remaining = vec![
make_loop(),
make_return("x"),
make_assignment("y", 999), // Unreachable
];
let builder = MirBuilder::new();
let plan = NormalizationPlanBox::plan_block_suffix(&builder, &remaining, "test", false)
.expect("Should not error");
assert!(plan.is_some());
let plan = plan.unwrap();
// Should consume only up to return (not the unreachable statement)
assert_eq!(plan.consumed, 2); // loop + return
assert_eq!(plan.kind, PlanKind::LoopWithPost { post_assign_count: 0 });
assert_eq!(plan.consumed, 1); // Only consume loop
assert_eq!(plan.kind, PlanKind::LoopOnly);
}
#[test]