phase29ao(p0): add coreplan composer scaffold

src/mir/builder/control_flow/plan/composer/mod.rs

@@ -0,0 +1,57 @@
+//! Phase 29ao P0: CorePlan composer scaffold (CanonicalLoopFacts -> CorePlan)
+
+use super::CorePlan;
+use crate::mir::builder::control_flow::plan::facts::skeleton_facts::SkeletonKind;
+use crate::mir::builder::control_flow::plan::normalize::CanonicalLoopFacts;
+use crate::mir::builder::control_flow::plan::planner::Freeze;
+
+#[allow(dead_code)]
+pub(in crate::mir::builder) fn try_compose_core_plan_from_canonical_facts(
+    facts: &CanonicalLoopFacts,
+) -> Result<Option<CorePlan>, Freeze> {
+    debug_assert!(
+        matches!(facts.skeleton_kind, SkeletonKind::Loop),
+        "composer expects Loop skeleton facts only"
+    );
+    Ok(None)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::try_compose_core_plan_from_canonical_facts;
+    use crate::mir::builder::control_flow::plan::facts::feature_facts::LoopFeatureFacts;
+    use crate::mir::builder::control_flow::plan::facts::loop_facts::LoopFacts;
+    use crate::mir::builder::control_flow::plan::facts::scan_shapes::{
+        ConditionShape, StepShape,
+    };
+    use crate::mir::builder::control_flow::plan::facts::skeleton_facts::{
+        SkeletonFacts, SkeletonKind,
+    };
+    use crate::mir::builder::control_flow::plan::normalize::canonicalize_loop_facts;
+
+    #[test]
+    fn composer_scaffold_returns_none() {
+        let facts = LoopFacts {
+            condition_shape: ConditionShape::Unknown,
+            step_shape: StepShape::Unknown,
+            skeleton: SkeletonFacts {
+                kind: SkeletonKind::Loop,
+            },
+            features: LoopFeatureFacts::default(),
+            scan_with_init: None,
+            split_scan: None,
+            pattern1_simplewhile: None,
+            pattern3_ifphi: None,
+            pattern4_continue: None,
+            pattern5_infinite_early_exit: None,
+            pattern8_bool_predicate_scan: None,
+            pattern9_accum_const_loop: None,
+            pattern2_break: None,
+            pattern2_loopbodylocal: None,
+        };
+        let canonical = canonicalize_loop_facts(facts);
+        let composed =
+            try_compose_core_plan_from_canonical_facts(&canonical).expect("Ok");
+        assert!(composed.is_none());
+    }
+}

src/mir/builder/control_flow/plan/mod.rs

@@ -35,6 +35,8 @@ pub(in crate::mir::builder) mod verifier;
 pub(in crate::mir::builder) mod facts;
 pub(in crate::mir::builder) mod normalize;
 pub(in crate::mir::builder) mod planner;
+// Phase 29ao P0: CorePlan composer scaffold (unused)
+pub(in crate::mir::builder) mod composer;
 pub(in crate::mir::builder) mod emit;
 // Phase 29ai P6: Extractors moved into plan layer
 pub(in crate::mir::builder) mod extractors;