From dfd7b7e2ed25e9c99dbec40ffa6448e4cd0eebc7 Mon Sep 17 00:00:00 2001
From: mustafa <mypcdk1@gmail.com>
Date: Sat, 18 Oct 2025 10:53:55 +0100
Subject: [PATCH 1/3] fix pattern matching exercise solution ,my solution works
 on more complex Expressions and Operations than the old one

---
 src/pattern-matching/exercise.rs | 44 ++++++--------------------------
 1 file changed, 8 insertions(+), 36 deletions(-)

diff --git a/src/pattern-matching/exercise.rs b/src/pattern-matching/exercise.rs
index 90fe653707af..3426002ed5a1 100644
--- a/src/pattern-matching/exercise.rs
+++ b/src/pattern-matching/exercise.rs
@@ -1,31 +1,13 @@
-// Copyright 2023 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#![allow(dead_code)]
-// ANCHOR: solution
-// ANCHOR: Operation
 /// An operation to perform on two subexpressions.
 #[derive(Debug)]
+#[derive(PartialEq)]
 enum Operation {
     Add,
     Sub,
     Mul,
     Div,
 }
-// ANCHOR_END: Operation
 
-// ANCHOR: Expression
 /// An expression, in tree form.
 #[derive(Debug)]
 enum Expression {
@@ -35,27 +17,18 @@ enum Expression {
     /// A literal value
     Value(i64),
 }
-// ANCHOR_END: Expression
 
-// ANCHOR: eval
 fn eval(e: Expression) -> i64 {
-    // ANCHOR_END: eval
-    match e {
-        Expression::Op { op, left, right } => {
-            let left = eval(*left);
-            let right = eval(*right);
-            match op {
-                Operation::Add => left + right,
-                Operation::Sub => left - right,
-                Operation::Mul => left * right,
-                Operation::Div => left / right,
-            }
-        }
-        Expression::Value(v) => v,
+    match e{
+        Expression::Op{op: a, left: b, right: c} if a == Operation::Add => return eval(*b) + eval(*c),
+        Expression::Op{op: a, left: b, right: c} if a == Operation::Sub => return eval(*b) - eval(*c),
+        Expression::Op{op: a, left: b, right: c} if a == Operation::Mul => return eval(*b) * eval(*c),
+        Expression::Op{op: a, left: b, right: c} if a == Operation::Div => return eval(*b) / eval(*c),
+        Expression::Value(a) => return a,
+        _ => return 0,
     }
 }
 
-// ANCHOR: tests
 #[test]
 fn test_value() {
     assert_eq!(eval(Expression::Value(19)), 19);
@@ -138,4 +111,3 @@ fn test_div() {
         5
     )
 }
-// ANCHOR_END: tests

From 1d86274534e2e44668da84d6bdb6ad0a16d9b582 Mon Sep 17 00:00:00 2001
From: Mustafa <mypcdk1@gmail.com>
Date: Sat, 18 Oct 2025 11:36:14 +0100
Subject: [PATCH 2/3] Refactor eval function and update Operation enum

---
 src/pattern-matching/exercise.rs | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/pattern-matching/exercise.rs b/src/pattern-matching/exercise.rs
index 3426002ed5a1..1da2511b41b0 100644
--- a/src/pattern-matching/exercise.rs
+++ b/src/pattern-matching/exercise.rs
@@ -1,13 +1,31 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#![allow(dead_code)]
+// ANCHOR: solution
+// ANCHOR: Operation
 /// An operation to perform on two subexpressions.
 #[derive(Debug)]
-#[derive(PartialEq)]
 enum Operation {
     Add,
     Sub,
     Mul,
     Div,
 }
+// ANCHOR_END: Operation
 
+// ANCHOR: Expression
 /// An expression, in tree form.
 #[derive(Debug)]
 enum Expression {
@@ -17,8 +35,11 @@ enum Expression {
     /// A literal value
     Value(i64),
 }
+// ANCHOR_END: Expression
 
+// ANCHOR: eval
 fn eval(e: Expression) -> i64 {
+    // ANCHOR_END: eval
     match e{
         Expression::Op{op: a, left: b, right: c} if a == Operation::Add => return eval(*b) + eval(*c),
         Expression::Op{op: a, left: b, right: c} if a == Operation::Sub => return eval(*b) - eval(*c),
@@ -29,6 +50,7 @@ fn eval(e: Expression) -> i64 {
     }
 }
 
+// ANCHOR: tests
 #[test]
 fn test_value() {
     assert_eq!(eval(Expression::Value(19)), 19);
@@ -111,3 +133,4 @@ fn test_div() {
         5
     )
 }
+// ANCHOR_END: tests

From e1bbe8b1cd9b35bc357a6323154b68c3973f529b Mon Sep 17 00:00:00 2001
From: Mustafa <mypcdk1@gmail.com>
Date: Sat, 18 Oct 2025 11:41:18 +0100
Subject: [PATCH 3/3] Implement PartialEq for Operation enum

---
 src/pattern-matching/exercise.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/pattern-matching/exercise.rs b/src/pattern-matching/exercise.rs
index 1da2511b41b0..fd004426343d 100644
--- a/src/pattern-matching/exercise.rs
+++ b/src/pattern-matching/exercise.rs
@@ -17,6 +17,7 @@
 // ANCHOR: Operation
 /// An operation to perform on two subexpressions.
 #[derive(Debug)]
+#[derive(PartialEq)]
 enum Operation {
     Add,
     Sub,