Working on linq queries

.vscode/launch.json

@@ -0,0 +1,27 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            // Use IntelliSense to find out which attributes exist for C# debugging
+            // Use hover for the description of the existing attributes
+            // For further information visit https://github.com/OmniSharp/omnisharp-vscode/blob/master/debugger-launchjson.md
+            "name": ".NET Core Launch (console)",
+            "type": "coreclr",
+            "request": "launch",
+            "preLaunchTask": "build",
+            // If you have changed target frameworks, make sure to update the program path.
+            "program": "${workspaceFolder}/Introduction/bin/Debug/netcoreapp3.1/Introduction.dll",
+            "args": [],
+            "cwd": "${workspaceFolder}/Introduction",
+            // For more information about the 'console' field, see https://aka.ms/VSCode-CS-LaunchJson-Console
+            "console": "internalConsole",
+            "stopAtEntry": false
+        },
+        {
+            "name": ".NET Core Attach",
+            "type": "coreclr",
+            "request": "attach",
+            "processId": "${command:pickProcess}"
+        }
+    ]
+}

.vscode/tasks.json

@@ -0,0 +1,42 @@
+{
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "build",
+            "command": "dotnet",
+            "type": "process",
+            "args": [
+                "build",
+                "${workspaceFolder}/Introduction/Introduction.csproj",
+                "/property:GenerateFullPaths=true",
+                "/consoleloggerparameters:NoSummary"
+            ],
+            "problemMatcher": "$msCompile"
+        },
+        {
+            "label": "publish",
+            "command": "dotnet",
+            "type": "process",
+            "args": [
+                "publish",
+                "${workspaceFolder}/Introduction/Introduction.csproj",
+                "/property:GenerateFullPaths=true",
+                "/consoleloggerparameters:NoSummary"
+            ],
+            "problemMatcher": "$msCompile"
+        },
+        {
+            "label": "watch",
+            "command": "dotnet",
+            "type": "process",
+            "args": [
+                "watch",
+                "run",
+                "${workspaceFolder}/Introduction/Introduction.csproj",
+                "/property:GenerateFullPaths=true",
+                "/consoleloggerparameters:NoSummary"
+            ],
+            "problemMatcher": "$msCompile"
+        }
+    ]
+}

Queries/MyLinq.cs

@@ -18,11 +18,9 @@ namespace Queries
             {
                 if (predicate(item))
                 {
-                    result.Add(item);
+                    yield return item;
                 }
             }
-
-            return result;
         }
     }
 }

yield_test/Program.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections;
+
+namespace yield_test
+{
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            foreach (var number in GetNumbers())
+            {
+                Console.WriteLine(number);
+            }
+        }
+
+        static IEnumerable GetNumbers()
+        {
+            yield return 1;
+            yield return 2;
+            yield return 3;
+        }
+    }
+}

yield_test/yield_test.csproj

@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+</Project>