Unit tests for range

This gives examples of how to use the class.

Author: romainbrenguier

unit/Makefile

@@ -42,6 +42,7 @@ SRC += analyses/ai/ai.cpp \
        util/message.cpp \
        util/optional.cpp \
        util/pointer_offset_size.cpp \
+       util/range.cpp \
        util/replace_symbol.cpp \
        util/sharing_map.cpp \
        util/sharing_node.cpp \

unit/util/range.cpp

@@ -0,0 +1,66 @@
+/*******************************************************************\
+
+Module: Unit tests for range
+
+Author: Romain Brenguier, romain.brenguier@diffblue.com
+
+\*******************************************************************/
+
+#include <vector>
+
+#include <util/range.h>
+#include "../testing-utils/catch.hpp"
+
+SCENARIO("range tests", "[core][util][range]")
+{
+  GIVEN("A vector with three strings")
+  {
+    std::vector<std::string> list;
+    list.emplace_back("abc");
+    list.emplace_back("cdef");
+    list.emplace_back("acdef");
+    auto range = make_range(list);
+    std::size_t total_length = 0;
+    THEN("Use range-for to compute the total length")
+    {
+      for(const auto &s : range)
+        total_length += s.length();
+      REQUIRE(total_length == 12);
+    }
+    THEN("Use map to compute individual lengths")
+    {
+      auto length_range = make_range(list)
+        .map<std::size_t>([](const std::string &s){ return s.length();});
+      auto it = length_range.begin();
+      REQUIRE(*it == 3);
+      ++it;
+      REQUIRE(*it == 4);
+      ++it;
+      REQUIRE(*it == 5);
+      ++it;
+      REQUIRE(it == length_range.end());
+    }
+    THEN("Filter using lengths")
+    {
+      auto filtered_range = make_range(list)
+        .filter([&](const std::string &s) { return s.length() == 4;});
+      auto it = filtered_range.begin();
+      REQUIRE(*it == "cdef");
+      ++it;
+      REQUIRE(it == filtered_range.end());
+    }
+    THEN("Filter, map and use range-for on the same list")
+    {
+      auto range = make_range(list)
+          .filter([&](const std::string &s) -> bool { return s[0] == 'a';})
+          .map<std::size_t>([&](const std::string &s) { return s.length(); });
+      // Note that everything is performed on the fly, so none of the filter
+      // and map functions have been computed yet, and no intermediary container
+      // is created.
+      std::size_t total = 0;
+      for(const auto &l : range)
+        total += l;
+      REQUIRE(total == 8);
+    }
+  }
+}