Add SequencesAndYields.kt

Author: pambrose

README.md

@@ -2,6 +2,7 @@
 
 The repo was motivated by [this post](https://medium.com/@desaismital/declarative-pipelines-in-kotlin-b9e18e77f2c5).
 
+* [Sequences and Yields](src/main/kotlin/org/athenian/SequencesAndYields.kt)
 * [Collection Operations](src/main/kotlin/org/athenian/CollectionOperations.kt)
 * [Chained Operations](src/main/kotlin/org/athenian/ChainedOperations.kt)
 * [Easy vs Lazy Ordering](src/main/kotlin/org/athenian/EvaluationOrdering.kt)

src/main/kotlin/org/athenian/CollectionOperations.kt

@@ -10,11 +10,6 @@ fun evenNumbers(max: Int): Sequence<Int> {
 }
 
 fun main() {
-    print("Even numbers <= 10: ")
-    for (i in evenNumbers(10))
-        print("$i ")
-    println()
-
     print("Even numbers <= 10: ")
     evenNumbers(10).forEach { print("$it ") }
     println()

src/main/kotlin/org/athenian/SequencesAndYields.kt

@@ -0,0 +1,41 @@
+package org.athenian
+
+fun main() {
+    val numbers =
+        sequence {
+            println("one")
+            yield(1)
+
+            println("two")
+            yield(2)
+
+            println("three")
+            yield(3)
+
+            println("Sequence finished...")
+        }
+
+    for (n in numbers)
+        println("number = $n")
+    println("Done...")
+
+    print("Odd numbers <= 10: ")
+    for (i in oddNumbers(10))
+        print("$i ")
+    println()
+
+    print("Odd numbers <= 20: ")
+    for (i in oddNumbers(20))
+        print("$i ")
+    println()
+}
+
+fun oddNumbers(max: Int): Sequence<Int> {
+    return sequence {
+        for (i in 0..max) {
+            if (i % 2 != 0)
+                yield(i)
+        }
+    }
+}
+