Mmichaelis/updating tables

src/Chapter13.Tests/Table13.01.Tests.cs

@@ -0,0 +1,25 @@
+using AddisonWesley.Michaelis.EssentialCSharp.Shared.Tests;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter13.Table13_01.Tests;
+
+[TestClass]
+public class LambdaHighlightTests
+{
+
+    [TestMethod]
+    /* 1. */ [DataRow(".a")]
+    /* 2. */ [DataRow(".b")]
+    /* 3. */ [DataRow(".c")]
+    /* 4. */ [DataRow(".d", "CS0023")]
+    /* 5. */ [DataRow(".e", "CS0837")]
+    /* 6. */ [DataRow(".f", "CS0029", "CS1662")]
+    /* 7. */ [DataRow(".g", "CS8070", "CS1632")]
+    /* 8. */ [DataRow(".h", "CS0103")]
+    /* 9. */ [DataRow(".i", "CS0165")]
+    /* 10. */ [DataRow(".j", "CS0165")]
+    public async Task ParseAndCompile(string fileNameSuffix, params string[] errorIds)
+    {
+        await CompilerAssert.CompileAsync($"Table13.01{fileNameSuffix}.LambdaExpressionNotesAndExamples.cs", errorIds);
+    }
+}

src/Chapter13/Table13.01.a.LambdaExpressionNotesAndExamples.cs

@@ -0,0 +1,16 @@
+// Justification: Only snippets of source code shown for elucidation.
+#pragma warning disable CS0168 // Variable is declared but never used
+
+namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter13.Table13_01;
+
+public partial class LambdaExpressionNotesAndExamples
+{
+    // 1.
+    public static void DiscardParameters()
+    {
+#if !NET6_0_OR_GREATER
+        Action<int, int> x = (_, _)=>
+            Console.WriteLine("This is a test.");
+#endif
+    }
+}

src/Chapter13/Table13.01.b.LambdaExpressionNotesAndExamples.cs

@@ -0,0 +1,18 @@
+// Justification: Only snippets of source code shown for elucidation.
+#pragma warning disable CS0168 // Variable is declared but never used
+
+namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter13.Table13_01;
+
+public partial class LambdaExpressionNotesAndExamples
+{
+    // 2.
+    static public void TypeInferenceOfExpression()
+    {
+#if !NET6_0_OR_GREATER
+        //You can assign lambda
+        //expression to an implicitly
+        //typed local variable starting C#10
+        var v = (int x) => x;
+#endif
+    }
+}

src/Chapter13/Table13.01.c.LambdaExpressionNotesAndExamples.cs

@@ -0,0 +1,17 @@
+// Justification: Only snippets of source code shown for elucidation.
+#pragma warning disable CS0168 // Variable is declared but never used
+
+namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter13.Table13_01;
+
+public partial class LambdaExpressionNotesAndExamples
+{
+    // 3.
+    static public void ExpressionsCanHaveReturnTypes()
+    {
+#if !NET6_0_OR_GREATER
+        Action action = void () => { };
+        var func = short?(long number) => 
+            number <= short.MaxValue ? (short)number : null;
+#endif
+    }
+}

src/Chapter13/Table13.01.d.LambdaExpressionNotesAndExamples.cs

@@ -0,0 +1,19 @@
+// Justification: Only snippets of source code shown for elucidation.
+#pragma warning disable CS0168 // Variable is declared but never used
+
+namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter13.Table13_01;
+
+public partial class LambdaExpressionNotesAndExamples
+{
+    // 4.
+    public static void MemberMethodsOnExpressions()
+    {
+    //#if COMPILEERROR
+    #if !NET6_0_OR_GREATER
+        //ERROR: Operator "." cannot be applied to
+        //operand of type "lambda expression"
+        string s = ((int x) => x).ToString();
+    #endif
+    //#endif // COMPILEERROR
+    }
+}

src/Chapter13/Table13.01.e.LambdaExpressionNotesAndExamples.cs

@@ -0,0 +1,20 @@
+// Justification: Only snippets of source code shown for elucidation.
+#pragma warning disable CS0168 // Variable is declared but never used
+
+namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter13.Table13_01;
+
+public partial class LambdaExpressionNotesAndExamples
+{
+    // 5.
+    public static void PatternMatchingOnType()
+    {
+//#if COMPILEERROR
+#if !NET6_0_OR_GREATER
+        //ERROR: The first operand of an "is" or "as"
+        //operator may not be a lambda expression or
+        //anonymous method
+        bool b = ((int x) => x) is Func<int,int>;
+#endif
+//#endif // COMPILEERROR
+    }
+}

src/Chapter13/Table13.01.f.LambdaExpressionNotesAndExamples.cs

@@ -0,0 +1,19 @@
+// Justification: Only snippets of source code shown for elucidation.
+#pragma warning disable CS0168 // Variable is declared but never used
+
+namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter13.Table13_01;
+
+public partial class LambdaExpressionNotesAndExamples
+{
+    // 6.
+    public static void ConvertingToImproperDelegate()
+    {
+//#if COMPILEERROR
+#if !NET6_0_OR_GREATER
+        //ERROR: Lambda expression is not compatible
+        //with Func<int, bool> type
+        Func<int, bool> f = (int x) => x;
+#endif
+//#endif // COMPILEERROR
+    }
+}

src/Chapter13/Table13.01.g.LambdaExpressionNotesAndExamples.cs

@@ -0,0 +1,30 @@
+// Justification: Only snippets of source code shown for elucidation.
+#pragma warning disable CS0168 // Variable is declared but never used
+
+namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter13.Table13_01;
+
+public partial class LambdaExpressionNotesAndExamples
+{
+    // 7.
+    public static void JumpStatementsToOutOfScopeDestinations()
+    {
+        //#if COMPILEERROR
+#if !NET6_0_OR_GREATER
+        //ERROR: Control cannot leave the body of an
+        //anonymous method or lambda expression
+        string[] args = { "/File", "fileThatMostCertainlyDoesNotExist" };
+        Func<string> f;
+        switch (args[0])
+        {
+            case "/File":
+                f = () =>
+                {
+                    if (!File.Exists(args[1]))
+                        break;
+                    return args[1];
+                };
+        }
+#endif
+        //#endif // COMPILEERROR
+    }
+}

src/Chapter13/Table13.01.h.LambdaExpressionNotesAndExamples.cs

@@ -0,0 +1,21 @@
+// Justification: Only snippets of source code shown for elucidation.
+#pragma warning disable CS0168 // Variable is declared but never used
+
+namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter13.Table13_01;
+
+public partial class LambdaExpressionNotesAndExamples
+{
+    // 8.
+    public static void AccessingParametersAndLocalsOutOfBody()
+    {
+//#if COMPILEERROR
+#if !NET6_0_OR_GREATER
+    //ERROR: The name "first" does not
+    //exist in the current context
+    Func <int, int, bool> expression =
+        (first, second) => first > second;
+    first++;
+#endif
+//#endif // COMPILEERROR
+    }
+}

src/Chapter13/Table13.01.i.LambdaExpressionNotesAndExamples.cs

@@ -0,0 +1,24 @@
+// Justification: Only snippets of source code shown for elucidation.
+#pragma warning disable CS0168 // Variable is declared but never used
+
+namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter13.Table13_01;
+
+public partial class LambdaExpressionNotesAndExamples
+{
+    // 9.
+    public static void UsingOutParameters()
+    {
+//#if COMPILEERROR
+#if !NET6_0_OR_GREATER
+    int number;
+    Func <string, bool> f =
+        text => int.TryParse(text, out number);
+    if (f("1"))
+    {
+      //ERROR: Use of unassigned local variable
+        System.Console.Write(number);
+    }
+#endif
+//#endif // COMPILEERROR
+    }
+}

src/Chapter13/Table13.01.j.LambdaExpressionNotesAndExamples.cs

@@ -0,0 +1,25 @@
+// Justification: Only snippets of source code shown for elucidation.
+#pragma warning disable CS0168 // Variable is declared but never used
+
+namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter13.Table13_01;
+
+public partial class LambdaExpressionNotesAndExamples
+{
+    // 10.
+    public static void CompilerWillNotDetectInLambdaAssignment()
+    {
+        //#if COMPILEERROR
+#if !NET6_0_OR_GREATER
+
+        int number;
+        Func<int, bool> isFortyTwo =
+          x => 42 == (number = x);
+        if (isFortyTwo(42))
+        {
+            // ERROR: Use of unassigned local variable
+            System.Console.Write(number);
+        }
+#endif
+        //#endif // COMPILEERROR
+    }
+}