From 5f2fdb01bdb9892cb8cf5bf1b1787db36587e1d6 Mon Sep 17 00:00:00 2001
From: Adrian Kummerlaender
Date: Tue, 20 Jan 2015 17:06:20 +0100
Subject: Implemented higher order list queries `All` and `Any` * in terms of
 `Fold` and `Map`, not the most efficient but reasonably concise * added
 appropriate test cases

---
 src/list/operation/higher/query.h | 30 ++++++++++++++++++++++++
 test.cc                           | 49 ++++++++++++++++++++++++++++++++++++++-
 2 files changed, 78 insertions(+), 1 deletion(-)
 create mode 100644 src/list/operation/higher/query.h

diff --git a/src/list/operation/higher/query.h b/src/list/operation/higher/query.h
new file mode 100644
index 0000000..56bb203
--- /dev/null
+++ b/src/list/operation/higher/query.h
@@ -0,0 +1,30 @@
+#ifndef TYPEASVALUE_SRC_LIST_OPERATION_HIGHER_QUERY_H_
+#define TYPEASVALUE_SRC_LIST_OPERATION_HIGHER_QUERY_H_
+
+#include "operation/logic.h"
+
+namespace tav {
+
+template <
+	template<typename> class Function,
+	typename                 List
+>
+using Any = Fold<
+	Or,
+	Boolean<false>,
+	typename Map<Function, List>::type
+>;
+
+template <
+	template<typename> class Function,
+	typename                 List
+>
+using All = Fold<
+	And,
+	Boolean<true>,
+	typename Map<Function, List>::type
+>;
+
+}
+
+#endif  // TYPEASVALUE_SRC_LIST_OPERATION_HIGHER_QUERY_H_
diff --git a/test.cc b/test.cc
index 37f83b7..3457a60 100644
--- a/test.cc
+++ b/test.cc
@@ -7,6 +7,7 @@
 #include "list/list.h"
 #include "list/operation/higher/fold.h"
 #include "list/operation/higher/misc.h"
+#include "list/operation/higher/query.h"
 
 int main(int, char **) { }
 
@@ -382,7 +383,7 @@ static_assert(
 			tav::List<tav::Int<1>, tav::Int<2>, tav::Int<3>>::type
 		>::type
 	>::value,
-	"(filter odd (list 1 2 3)) != (list 1 3)"
+	"(filter odd? (list 1 2 3)) != (list 1 3)"
 );
 
 // list reverse
@@ -396,3 +397,49 @@ static_assert(
 	>::value,
 	"(reverse (list 1 2 3)) != (list 3 2 1)"
 );
+
+// list query
+
+static_assert(
+	std::is_same<
+		tav::Boolean<true>,
+		tav::Any<
+			tav::Odd,
+			tav::List<tav::Int<1>, tav::Int<2>, tav::Int<3>>::type
+		>::type
+	>::value,
+	"(any odd? (list 1 2 3)) != #t"
+);
+
+static_assert(
+	std::is_same<
+		tav::Boolean<false>,
+		tav::Any<
+			tav::Odd,
+			tav::List<tav::Int<2>, tav::Int<4>, tav::Int<6>>::type
+		>::type
+	>::value,
+	"(any odd? (list 2 4 6)) != #f"
+);
+
+static_assert(
+	std::is_same<
+		tav::Boolean<true>,
+		tav::All<
+			tav::Even,
+			tav::List<tav::Int<2>, tav::Int<4>, tav::Int<6>>::type
+		>::type
+	>::value,
+	"(all even? (list 2 4 6)) != #t"
+);
+
+static_assert(
+	std::is_same<
+		tav::Boolean<false>,
+		tav::All<
+			tav::Odd,
+			tav::List<tav::Int<1>, tav::Int<2>, tav::Int<3>>::type
+		>::type
+	>::value,
+	"(all odd? (list 1 2 3)) != #f"
+);
-- 
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