kharkiv alt.net meetup

kolesnick · Apr 18, 2019 · 8a9980a · 8a9980a
1 parent 5f14604
commit 8a9980a
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Showing 9 changed files with 112 additions and 108 deletions.
diff --git a/ConsoleApp/ConsoleApp.csproj b/ConsoleApp/ConsoleApp.csproj
@@ -5,7 +5,7 @@
     <TargetFramework>netcoreapp3.0</TargetFramework>
     <LangVersion>8.0</LangVersion>
     <NullableContextOptions>enable</NullableContextOptions>
-    <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 
   <ItemGroup>

diff --git a/ConsoleApp/DisposableRefStructs.cs b/ConsoleApp/DisposableRefStructs.cs
@@ -8,7 +8,9 @@ internal class DisposableRefStructs
         public static void Showcase ()
         {
             using (var x = new RefStruct ())
+            {
                 WriteLine ("I pretend to use ref struct here.");
+            }
         }
 
         ref struct RefStruct

diff --git a/ConsoleApp/IndicesAndRanges.cs b/ConsoleApp/IndicesAndRanges.cs
@@ -1,69 +1,69 @@
-using System;
-using System.Linq;
-using static System.Console;
-
-namespace ConsoleApp
-{
-    public static class IndicesAndRanges
-    {
-        const string TearsInRain =
-            "I've seen things you people wouldn't believe. " + // 7
-            "Attack ships on fire off the shoulder of Orion. " + // 9
-            "I watched C-beams glitter in the dark near the Tannhäuser Gate. " + // 11
-            "All those moments will be lost in time, like tears in rain. " + // 12
-            "Time to die."; // 3
-
-        public static void Demo () => Demo1 (); // of 5
-
-        static void Demo1 ()
-        {
-            string[] words = TearsInRain.Split (' ');
-
-            WriteLine (words[3]); // you
-            WriteLine (words[5]); // wouldn't
-            WriteLine (words[41]); // die
-        }
-
-        static void Demo2 ()
-        {
-            string[] words = TearsInRain.Split (' ');
-
-            for (int index = 0; index < words.Length; index++)
-                WriteLine (words[index]);
-        }
-
-        static void Demo3 ()
-        {
-            string[] words =
-            {
-                "I've", "seen", "things", "you", "people", "wouldn't", "believe."
-            };
-
-            string[] range = words[1..3]; // play here
-
-            WriteLine (string.Join (' ', range));
-        }
-
-        static void Demo4 ()
-        {
-            Span<string> words = TearsInRain.Split(' ').AsSpan();
-
-            var lastWords = words[^3..];
-
-            foreach (var word in lastWords)
-                WriteLine (word);
-        }
-
-        static void Demo5 ()
-        {
-            Span<string> words = TearsInRain.Split(' ').AsSpan();
-
-            var lastWords = words[^3..];
-
-            lastWords[^1] = "live.";
-
-            foreach (var word in words)
-                WriteLine(word);
-        }
-    }
+using System;
+using System.Linq;
+using static System.Console;
+
+namespace ConsoleApp
+{
+    public static class IndicesAndRanges
+    {
+        const string TearsInRain =
+            "I've seen things you people wouldn't believe. " + // 7
+            "Attack ships on fire off the shoulder of Orion. " + // 9
+            "I watched C-beams glitter in the dark near the Tannhäuser Gate. " + // 11
+            "All those moments will be lost in time, like tears in rain. " + // 12
+            "Time to die."; // 3
+
+        public static void Demo () => Demo5 (); // of 5
+
+        static void Demo3 ()
+        {
+            string[] words =
+            {
+                "I've", "seen", "things", "you", "people", "wouldn't", "believe."
+            };
+
+            string[] range = words[..3]; // play here
+
+            WriteLine (string.Join (' ', range));
+        }
+
+        static void Demo2 ()
+        {
+            string[] words = TearsInRain.Split (' ');
+
+            for (int index = 0; index < words.Length; index++)
+                WriteLine (words[^index]);
+        }
+
+        static void Demo1 ()
+        {
+            string[] words = TearsInRain.Split (' ');
+
+            WriteLine (words[3]); // you
+            WriteLine (words[5]); // wouldn't
+            WriteLine (words[^1]); // die
+        }
+
+        static void Demo4 ()
+        {
+            Span<string> words = TearsInRain.Split(' ').AsSpan();
+
+            Span<string> lastWords = words[^4..];
+
+            foreach (var word in lastWords)
+                WriteLine (word);
+        }
+
+        static void Demo5 ()
+        {
+            Span<string> words = TearsInRain.Split(' ').AsSpan();
+
+            var lastWords = words[^3..];
+
+            lastWords[^1] = "live.";
+
+            foreach (var word in words)
+                WriteLine(word);
+        }
+    }
 }
diff --git a/ConsoleApp/NullableReferenceTypes.cs b/ConsoleApp/NullableReferenceTypes.cs
@@ -6,7 +6,7 @@ namespace ConsoleApp
 {
     internal static class NullableReferenceTypes
     {
-        public static void Demo () => Demo1 (); // of 5
+        public static void Demo () => Demo5 (); // of 5
 
         static void Demo1 ()
         {
@@ -20,16 +20,17 @@ static void LogDoubleLength (string value)
             int doubleLength = 2 * length;
             WriteLine (doubleLength);
         }
-
+        
         static int Length (string s) => s.Length;
+        static int? LengthUnsafe (string? s) => s?.Length;
 
         static void Demo2 ()
         {
             LogLength ("12345");
-            // TODO: LogLength (null);
+            LogLength (null);
         }
 
-        static void LogLength (string value) => WriteLine (Length (value));
+        static void LogLength (string? value) => WriteLine (LengthUnsafe (value));
 
         static void Demo3 ()
         {
@@ -42,7 +43,7 @@ static void Demo3 ()
         static void Demo4 ()
         {
             Module.LogLength ("12345");
-            // TODO: Module.LogLength (null);
+            Module.LogLengthUnsafe (null);
         }
 
         static void Demo5 ()

diff --git a/ConsoleApp/PatternMatching.cs b/ConsoleApp/PatternMatching.cs
@@ -12,21 +12,16 @@ enum Priority { Low, Normal, High }
 
     internal class PatternMatching
     {
-        public static void Demo () => Demo1 (Yesterday); // of 4
+        public static void Demo () => Demo4 (); // of 4
 
-        static void Demo1 (Day day)
-        {
-            var date =
-                day switch
-                {
-                    Yesterday => DateTime.Today.AddDays (-1),
-                    Today     => DateTime.Today,
-                    Tomorrow  => DateTime.Today.AddDays (-1),
-                    _         => throw new ArgumentOutOfRangeException (nameof(day)),
-                };
-
-            WriteLine (date); // TODO: refactor
-        }
+        static void Demo1 (Day day) =>
+            WriteLine (day switch
+            {
+                Yesterday => DateTime.Today.AddDays (-1),
+                Today     => DateTime.Today,
+                Tomorrow  => DateTime.Today.AddDays (-1),
+                _         => throw new ArgumentOutOfRangeException (nameof(day)),
+            });
 
         static void Demo2 ()
         {
@@ -41,7 +36,7 @@ static Priority Priority (Task task) =>
                 { Price:    Expensive } => High,
                 { Estimate: Yesterday } => High,
                 { Estimate: Tomorrow }  => Low,
-                _                       => Normal, // TODO: Bug
+                _                       => Normal,
             };
 
         static void Demo3 () =>
@@ -66,12 +61,15 @@ static void Demo4()
         static Priority Priority (Feature feature) =>
             feature switch
             {
-                (Expensive, _) => High,
+                (Expensive, _) => VeryHigh(),
                 (_, Yesterday) => High,
                 (_, Tomorrow)  => Low,
-                _ =>           Normal, // TODO: Enhancement
+                Enhancement _  => Low, 
+                (_,_)          => Normal,
             };
 
+        static Priority VeryHigh () => throw new Exception ("Please do this!");
+
         class Task
         {
             public Task (Price price, Day estimate)

diff --git a/ConsoleApp/Program.cs b/ConsoleApp/Program.cs
@@ -16,22 +16,22 @@ static void Main ()
             //IndicesAndRanges.Demo ();
 
             //DisposableRefStructs.Showcase ();
-            //UsingDeclarations.Showcase ();
+            //UsingDeclarations.Showcase();
             //await AsyncStreams.Showcase ();
-            //StaticLocalFunctions.Showcase ();
+            //StaticLocalFunctions.Showcase();
 
             //if (Now.Hour >= 20 && Now.Minute >= 30)
             //    Thread.Sleep (TimeSpan.FromMinutes (5));
 
-            //PatternMatching.Demo ();
+            //PatternMatching.Demo();
 
             //BillionDollarMistake.Read ();
             //NullableReferenceTypes.Demo ();
             //ScreenToGif.Showcase ();
 
             //Tickets.Giveaway ();
 
-            //Credits.Show ();
+            Credits.Show ();
         }
     }
 }
diff --git a/ConsoleApp/StaticLocalFunctions.cs b/ConsoleApp/StaticLocalFunctions.cs
@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using static System.Console;
 using static System.Linq.Enumerable;
 

diff --git a/ConsoleApp/Tickets.cs b/ConsoleApp/Tickets.cs
@@ -53,6 +53,10 @@ internal static class Tickets
 
         public static void Giveaway ()
         {
+            //Яков Олейник
+            //Сергей Руденко
+            //Александра Строна
+
             WriteLine (RandomAttendee ());
             WriteLine (RandomAttendee ());
             WriteLine (RandomAttendee ());

diff --git a/ConsoleApp/UsingDeclarations.cs b/ConsoleApp/UsingDeclarations.cs
@@ -1,5 +1,7 @@
 using System;
 using System.IO;
+using static System.Console;
+
 // ReSharper disable UseUsingVarLocalVariable
 
 namespace ConsoleApp
@@ -8,25 +10,21 @@ internal static class UsingDeclarations
     {
         public static void Showcase ()
         {
-            Before ();
-            //After ();
+            //Before ();
+            After ();
         }
 
         static void Before ()
         {
             using (var stream = new MemoryStream ())
+            using (var writer = new StreamWriter (stream) { AutoFlush = true })
             {
-                using (var writer = new StreamWriter (stream) { AutoFlush = true })
-                {
-                    writer.Write ("Memory stream contains this.");
+                using (var reader = new StreamReader (stream))
+                    WriteLine (reader.ReadToEnd ());
 
-                    stream.Position = 0;
+                writer.Write ("Memory stream contains this.");
 
-                    using (var reader = new StreamReader (stream))
-                    {
-                        Console.WriteLine (reader.ReadToEnd ());
-                    }
-                }
+                stream.Position = 0;
             }
         }
 
@@ -41,7 +39,7 @@ static void After ()
 
             using var reader = new StreamReader(stream);
 
-            Console.WriteLine(reader.ReadToEnd());
+            WriteLine(reader.ReadToEnd());
         }
     }
 }