Add Guard

Author: leogdion

Examples/Completed/conditionals/code.swift

@@ -31,4 +31,19 @@ let possibleName: String? = "John"
 let possibleAge: Int? = 30
 if let name = possibleName, let age = possibleAge {
     print("\(name) is \(age) years old")
+}
+
+// MARK: - Guard Statements
+func greet(person: [String: String]) {
+    guard let name = person["name"] else {
+        print("No name provided")
+        return
+    }
+    
+    guard let age = person["age"], let ageInt = Int(age) else {
+        print("Invalid age provided")
+        return
+    }
+    
+    print("Hello \(name), you are \(ageInt) years old")
 }

Examples/Completed/conditionals/dsl.swift

@@ -56,4 +56,23 @@ Group {
     } then: {
         Call("print", "\\(name) is \\(age) years old") 
     }
+
+    Function("greet", parameters: [Parameter("person", type: "[String: String]")]) {
+        Guard {
+            Let("name", "person[\"name\"]")
+        } else: {
+            Call("print", "No name provided")
+        }
+        Guard {
+            Let("age", "person[\"age\"]")
+            Let("ageInt", Init("Int") {
+                Parameter(unlabeled: "age")
+            })
+        } else: {
+            Call("print", "Invalid age provided")
+        }
+        Call("print", "Hello \\(name), you are \\(ageInt) years old")
+    }
+}.comment {
+    Line("MARK: - Guard Statements")
 }

Examples/Completed/conditionals/syntax.json

@@ -114,15 +114,46 @@ import Testing
           ParameterExp(name: "", value: "\"\\(name) is \\(age) years old\"")
         }
       }
+
+      // MARK: - Guard Statements
+      Function(
+        "greet",
+        {
+          Parameter(name: "person", type: "[String: String]")
+        }
+      ) {
+        Guard {
+          Let("name", "person[\"name\"]")
+        } else: {
+          Call("print") {
+            ParameterExp(name: "", value: "\"No name provided\"")
+          }
+        }
+
+        Guard {
+          Let("age", "person[\"age\"]")
+          Let("ageInt", "Int(age)")
+        } else: {
+          Call("print") {
+            ParameterExp(name: "", value: "\"Invalid age provided\"")
+          }
+        }
+
+        Call("print") {
+          ParameterExp(name: "", value: "\"Hello \\(name), you are \\(ageInt) years old\"")
+        }
+      }
+      .comment {
+        Line("MARK: - Guard Statements")
+      }
     }
 
     // Generate Swift from DSL
     var generated = program.generateCode()
     // Remove type annotations like ": Int =" for comparison to example code
     generated = generated.replacingOccurrences(
       of: ":\\s*\\w+\\s*=", with: "=", options: .regularExpression
-    )
-    .normalize()
+    ).normalize()
 
     // Load expected Swift from example file
     let projectRoot = URL(fileURLWithPath: FileManager.default.currentDirectoryPath)