From 34808ccf744f39a345edef3af824ac0bfe666180 Mon Sep 17 00:00:00 2001
From: davidemazzocchi <davide.mazzocchi@gmail.com>
Date: Tue, 11 Nov 2025 16:30:58 +0100
Subject: [PATCH] feat: allow predicate to generate an error and return it
 boxed

---
 .../heave/src/imp/catalog_for_each_mut.rs     |  4 ++--
 01.workspace/heave/src/str/failed_to.rs       | 24 ++++++++++++++++++-
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/01.workspace/heave/src/imp/catalog_for_each_mut.rs b/01.workspace/heave/src/imp/catalog_for_each_mut.rs
index de4820d..0eaa000 100644
--- a/01.workspace/heave/src/imp/catalog_for_each_mut.rs
+++ b/01.workspace/heave/src/imp/catalog_for_each_mut.rs
@@ -4,14 +4,14 @@ impl Catalog {
     pub fn for_each_mut<T, F>(&self, mut predicate: F) -> Result<(), FailedTo>
     where
         T: EAV,
-        F: FnMut(&mut T),
+        F: FnMut(&mut T) -> Result<(), Box<dyn error::Error>>,
     {
         self.on_items(|items| {
             for entity in items.values_mut() {
                 let original_item =
                     T::try_from(entity.clone()).map_err(|_| FailedTo::ConvertEntity)?;
                 let mut item = T::try_from(entity.clone()).map_err(|_| FailedTo::ConvertEntity)?;
-                predicate(&mut item);
+                predicate(&mut item).map_err(FailedTo::ExecutePredicate)?;
                 if item != original_item {
                     *entity = T::try_into(item).map_err(|_| FailedTo::ConvertObject)?;
                     entity.state = EntityState::Updated;
diff --git a/01.workspace/heave/src/str/failed_to.rs b/01.workspace/heave/src/str/failed_to.rs
index e8aced3..607939a 100644
--- a/01.workspace/heave/src/str/failed_to.rs
+++ b/01.workspace/heave/src/str/failed_to.rs
@@ -1,7 +1,7 @@
 use crate::*;
 
 /// Represents the possible failures that can occur in the library.
-#[derive(Debug, PartialEq, PartialOrd, Eq, Ord, Clone, Copy, Hash)]
+#[derive(Debug)]
 pub enum FailedTo {
     /// Failed to compose filter statement
     ComposeFilter,
@@ -11,6 +11,8 @@ pub enum FailedTo {
     ConvertObject,
     /// Failed to convert from Value to type.
     ConvertValue,
+    /// Failed to execute predicate to mutate an item.
+    ExecutePredicate(Box<dyn error::Error>),
     /// Failed to initialize the database.
     InitDatabase,
     /// Failed to load data from the database.
@@ -27,6 +29,26 @@ pub enum FailedTo {
     SQLite(sqlite::FailedTo),
 }
 
+impl PartialEq for FailedTo {
+    fn eq(&self, other: &FailedTo) -> bool {
+        matches!(
+            (self, other),
+            (FailedTo::ComposeFilter, FailedTo::ComposeFilter)
+                | (FailedTo::ConvertEntity, FailedTo::ConvertEntity)
+                | (FailedTo::ConvertObject, FailedTo::ConvertObject)
+                | (FailedTo::ConvertValue, FailedTo::ConvertValue)
+                | (FailedTo::ExecutePredicate(_), FailedTo::ExecutePredicate(_))
+                | (FailedTo::InitDatabase, FailedTo::InitDatabase)
+                | (FailedTo::LoadFromDB, FailedTo::LoadFromDB)
+                | (FailedTo::LockCatalog, FailedTo::LockCatalog)
+                | (FailedTo::MapAttribute, FailedTo::MapAttribute)
+                | (FailedTo::MapEntity, FailedTo::MapEntity)
+                | (FailedTo::PersistCatalog, FailedTo::PersistCatalog)
+                | (FailedTo::SQLite(_), FailedTo::SQLite(_))
+        )
+    }
+}
+
 impl From<sqlite::FailedTo> for FailedTo {
     fn from(value: sqlite::FailedTo) -> Self {
         Self::SQLite(value)