From 6549bb77f361b530e32258e4c009bd999f35c073 Mon Sep 17 00:00:00 2001
From: Maxim Vezenov <mvezenov@gmail.com>
Date: Wed, 17 Sep 2025 20:01:14 +0000
Subject: [PATCH 1/3] fix ArrayValue::flat_numeric_types

---
 compiler/noirc_evaluator/src/acir/arrays.rs | 8 +-------
 compiler/noirc_evaluator/src/acir/types.rs  | 9 +++++----
 2 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/compiler/noirc_evaluator/src/acir/arrays.rs b/compiler/noirc_evaluator/src/acir/arrays.rs
index 7b37d444036..90319355bc9 100644
--- a/compiler/noirc_evaluator/src/acir/arrays.rs
+++ b/compiler/noirc_evaluator/src/acir/arrays.rs
@@ -226,13 +226,6 @@ impl Context<'_> {
         }
 
         if let Some(store_value) = store_value {
-            // We should avoid storing a DynamicArray directly inside an Array. Instead we must allow
-            // the regular `array_set_value` to take place which reads the item from the block the
-            // dynamic array refers to, and writes items one by one. Otherwise subsequent operations
-            // with non-constant indexes will fail.
-            if matches!(store_value, AcirValue::DynamicArray(_)) {
-                return Ok(false);
-            }
             let side_effects_always_enabled =
                 self.acir_context.is_constant_one(&self.current_side_effects_enabled_var);
 
@@ -600,6 +593,7 @@ impl Context<'_> {
         };
 
         let value_types = self.convert_value(array, dfg).flat_numeric_types();
+        dbg!(value_types.clone());
         // Compiler sanity check
         assert_eq!(
             value_types.len(),
diff --git a/compiler/noirc_evaluator/src/acir/types.rs b/compiler/noirc_evaluator/src/acir/types.rs
index 81ae44575d6..0c291f5069a 100644
--- a/compiler/noirc_evaluator/src/acir/types.rs
+++ b/compiler/noirc_evaluator/src/acir/types.rs
@@ -110,9 +110,10 @@ impl Debug for AcirDynamicArray {
     fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(
             f,
-            "id: {}, len: {}, element_type_sizes: {:?}",
+            "id: {}, len: {}, value_types: {:?}, element_type_sizes: {:?}",
             self.block_id.0,
             self.len,
+            self.value_types,
             self.element_type_sizes.map(|block_id| block_id.0)
         )
     }
@@ -156,11 +157,11 @@ impl AcirValue {
 
     pub(super) fn flat_numeric_types(self) -> Vec<NumericType> {
         match self {
-            AcirValue::Array(_) => {
-                self.flatten().into_iter().map(|(_, typ)| typ.to_numeric_type()).collect()
+            AcirValue::Array(array) => {
+                array.into_iter().flat_map(|elem| elem.flat_numeric_types()).collect()
             }
             AcirValue::DynamicArray(AcirDynamicArray { value_types, .. }) => value_types,
-            _ => unreachable!("An AcirValue::Var cannot be used as an array value"),
+            AcirValue::Var(_, typ) => vec![typ.to_numeric_type()],
         }
     }
 }

From 0468590c5f4c393bde7d7bd45486b76d8e7a5bec Mon Sep 17 00:00:00 2001
From: Maxim Vezenov <mvezenov@gmail.com>
Date: Wed, 17 Sep 2025 20:04:25 +0000
Subject: [PATCH 2/3] cleanup

---
 compiler/noirc_evaluator/src/acir/arrays.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/compiler/noirc_evaluator/src/acir/arrays.rs b/compiler/noirc_evaluator/src/acir/arrays.rs
index 90319355bc9..f47fbaa3465 100644
--- a/compiler/noirc_evaluator/src/acir/arrays.rs
+++ b/compiler/noirc_evaluator/src/acir/arrays.rs
@@ -593,7 +593,6 @@ impl Context<'_> {
         };
 
         let value_types = self.convert_value(array, dfg).flat_numeric_types();
-        dbg!(value_types.clone());
         // Compiler sanity check
         assert_eq!(
             value_types.len(),

From da360a997e699ca7f32a556a396b5e526b78217f Mon Sep 17 00:00:00 2001
From: Maxim Vezenov <mvezenov@gmail.com>
Date: Thu, 18 Sep 2025 12:27:08 +0000
Subject: [PATCH 3/3] comments

---
 compiler/noirc_evaluator/src/acir/types.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/compiler/noirc_evaluator/src/acir/types.rs b/compiler/noirc_evaluator/src/acir/types.rs
index 0c291f5069a..7ccbf09fdef 100644
--- a/compiler/noirc_evaluator/src/acir/types.rs
+++ b/compiler/noirc_evaluator/src/acir/types.rs
@@ -147,6 +147,13 @@ impl AcirValue {
         }
     }
 
+    /// Fetch a flat list of ([AcirVar], [AcirType]).
+    ///
+    /// # Panics
+    /// If [AcirValue::DynamicArray] is supplied or an inner element of an [AcirValue::Array].
+    /// This is because an [AcirValue::DynamicArray] is simply a pointer to an array
+    /// and fetching its internal [AcirValue::Var] would require laying down opcodes to read its content.
+    /// This method should only be used where dynamic arrays are not a possible type.
     pub(super) fn flatten(self) -> Vec<(AcirVar, AcirType)> {
         match self {
             AcirValue::Var(var, typ) => vec![(var, typ)],
@@ -155,6 +162,9 @@ impl AcirValue {
         }
     }
 
+    /// Fetch a flat list of the [NumericType] contained within an array
+    /// An [AcirValue::DynamicArray] should already have a field representing
+    /// its types and should be supported here unlike [AcirValue::flatten]
     pub(super) fn flat_numeric_types(self) -> Vec<NumericType> {
         match self {
             AcirValue::Array(array) => {