Rename common to base.

1 files changed, 42 insertions, 0 deletions

diff --git a/include/cru/base/Range.h b/include/cru/base/Range.h
new file mode 100644
index 00000000..edc2ec55
--- /dev/null
+++ b/include/cru/base/Range.h
@@ -0,0 +1,42 @@
+#pragma once
+#include "Base.h"
+
+namespace cru {
+struct Range final {
+  constexpr static Range FromTwoSides(Index start, Index end) {
+    return Range(start, end - start);
+  }
+
+  constexpr static Range FromTwoSides(Index start, Index end, Index offset) {
+    return Range(start + offset, end - start);
+  }
+
+  constexpr Range() = default;
+  constexpr Range(const Index position, const Index count = 0)
+      : position(position), count(count) {}
+
+  Index GetStart() const { return position; }
+  Index GetEnd() const { return position + count; }
+
+  void ChangeEnd(Index new_end) { count = new_end - position; }
+
+  Range Normalize() const {
+    auto result = *this;
+    if (result.count < 0) {
+      result.position += result.count;
+      result.count = -result.count;
+    }
+    return result;
+  }
+
+  Range CoerceInto(Index min, Index max) const {
+    auto coerce = [min, max](Index index) {
+      return index > max ? max : (index < min ? min : index);
+    };
+    return Range::FromTwoSides(coerce(GetStart()), coerce(GetEnd()));
+  }
+
+  Index position = 0;
+  Index count = 0;
+};
+}  // namespace cru