[midend]重构了src目录

src/include/midend/range.h

@@ -0,0 +1,63 @@
+#pragma once
+
+#include <iterator>
+
+namespace sysy {
+
+/*!
+ * \defgroup utility Utilities
+ * @{
+ */
+
+/*!
+ * \brief `range` is an simple wrapper of an iterator pair [begin, end)
+ *
+ * Example usage
+ *
+ * ```cpp
+ *    vector<int> v = {1,2,3};
+ *    auto rg = make_range(v);
+ *    for (auto v : rg)
+ *      cout << v << '\n';
+ * ```
+ */
+template <typename IterT> struct range {
+  using iterator = IterT;
+  using value_type = typename std::iterator_traits<iterator>::value_type;
+  using reference = typename std::iterator_traits<iterator>::reference;
+
+private:
+  iterator b;
+  iterator e;
+
+public:
+  explicit range(iterator b, iterator e) : b(b), e(e) {}
+  iterator begin() { return b; }
+  iterator end() { return e; }
+  iterator begin() const { return b; }
+  iterator end() const { return e; }
+  auto size() const { return std::distance(b, e); }
+  auto empty() const { return b == e; }
+};
+
+//! create `range` object from iterator pair [begin, end)
+template <typename IterT> range<IterT> make_range(IterT b, IterT e) {
+  return range(b, e);
+}
+//! create `range` object from a container who has `begin()` and `end()` methods
+template <typename ContainerT>
+range<typename ContainerT::iterator> make_range(ContainerT &c) {
+  return make_range(c.begin(), c.end());
+}
+//! create `range` object from a container who has `begin()` and `end()` methods
+template <typename ContainerT>
+range<typename ContainerT::const_iterator> make_range(const ContainerT &c) {
+  return make_range(c.begin(), c.end());
+}
+
+/*!
+ * @}
+ */
+
+
+} // namespace sysy