add sources

05-данные-и-функции-функциональный-стиль/src/chapter-5-1/searching.d

@@ -0,0 +1,33 @@
+bool find1(int[] haystack, int needle)
+{
+    foreach (v; haystack)
+    {
+        if (v == needle)
+        {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+int[] find2(int[] haystack, int needle)
+{
+    while (haystack.length > 0 && haystack[0] != needle)
+    {
+        haystack = haystack[1 .. $];
+    }
+
+    return haystack;
+}
+
+unittest
+{
+    int[] a = [];
+    assert(find2(a, 5) == []);
+    a = [ 1, 2, 3 ];
+    assert(find2(a, 0) == []);
+    assert(find2(a, 1).length == 3);
+    assert(find2(a, 2).length == 2);
+    assert(a[0 .. $ - find2(a, 3).length] == [ 1, 2 ]);
+}