AK: Implement generic any_of algorithm

Problem:
- Raw loops are often written to validate that any values in a
  container meet a predicate, but raw loops are not as expressive as
  functions implementing well-named algorithms and are error-prone.

Solution:
- Implement a very generic form of `any_of`.

3 files changed, 93 insertions, 0 deletions

diff --git a/AK/AnyOf.h b/AK/AnyOf.h
new file mode 100644
index 0000000000..7e620d93dc
--- /dev/null
+++ b/AK/AnyOf.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2021, the SerenityOS developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/Iterator.h>
+
+namespace AK {
+
+template<typename Container, typename ValueType>
+constexpr bool any_of(
+    const SimpleIterator<Container, ValueType>& begin,
+    const SimpleIterator<Container, ValueType>& end,
+    const auto& predicate)
+{
+    for (auto iter = begin; iter != end; ++iter) {
+        if (predicate(*iter)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+}
diff --git a/AK/Tests/CMakeLists.txt b/AK/Tests/CMakeLists.txt
index 303fa219a1..103e91fcb0 100644
--- a/AK/Tests/CMakeLists.txt
+++ b/AK/Tests/CMakeLists.txt
@@ -1,5 +1,6 @@
 set(AK_TEST_SOURCES
     TestAllOf.cpp
+    TestAnyOf.cpp
     TestArray.cpp
     TestAtomic.cpp
     TestBase64.cpp
diff --git a/AK/Tests/TestAnyOf.cpp b/AK/Tests/TestAnyOf.cpp
new file mode 100644
index 0000000000..94e28572ad
--- /dev/null
+++ b/AK/Tests/TestAnyOf.cpp
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2021, the SerenityOS developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/TestSuite.h>
+
+#include <AK/AnyOf.h>
+#include <AK/Array.h>
+
+TEST_CASE(should_determine_if_predicate_applies_to_any_element_in_container)
+{
+    constexpr AK::Array<int, 10> a { 1 };
+
+    static_assert(AK::any_of(a.begin(), a.end(), [](auto elem) { return elem == 0; }));
+    static_assert(AK::any_of(a.begin(), a.end(), [](auto elem) { return elem == 1; }));
+    static_assert(!AK::any_of(a.begin(), a.end(), [](auto elem) { return elem == 2; }));
+
+    EXPECT(AK::any_of(a.begin(), a.end(), [](auto elem) { return elem == 0; }));
+    EXPECT(AK::any_of(a.begin(), a.end(), [](auto elem) { return elem == 1; }));
+    EXPECT(!AK::any_of(a.begin(), a.end(), [](auto elem) { return elem == 2; }));
+}
+
+TEST_MAIN(AllOf)