finished ch18.3 and ch18

.obsidian/workspace.json

@@ -35,6 +35,20 @@
               "title": "Implementing OO Design Pattern"
             }
           },
+          {
+            "id": "629d55df46f486d8",
+            "type": "leaf",
+            "state": {
+              "type": "markdown",
+              "state": {
+                "file": "Pattern Matching.md",
+                "mode": "source",
+                "source": false
+              },
+              "icon": "lucide-file",
+              "title": "Pattern Matching"
+            }
+          },
           {
             "id": "6ed9f182aa3d5f3e",
             "type": "leaf",
@@ -46,7 +60,7 @@
             }
           }
         ],
-        "currentTab": 1
+        "currentTab": 2
       }
     ],
     "direction": "vertical"
@@ -189,10 +203,11 @@
       "command-palette:Open command palette": false
     }
   },
-  "active": "f9ef446f856cead7",
+  "active": "629d55df46f486d8",
   "lastOpenFiles": [
-    "Trait Objects that allow for Values of Different Types.md",
     "Implementing OO Design Pattern.md",
+    "Pattern Matching.md",
+    "Trait Objects that allow for Values of Different Types.md",
     "Characteristics of OO Languages.md",
     "OOP Programming Features.md",
     "Futures, Tasks and Threads Together.md",
@@ -216,7 +231,6 @@
     "Improving The IO Project.md",
     "Tests.md",
     "The Preformance Closures and Iterators.md",
-    "minigrep/README.md",
     "minigrep/src/lib.rs",
     "does_not_compile.svg",
     "Untitled.canvas",