add mstch

1 files changed, 113 insertions, 0 deletions

diff --git a/lib/mstch/include/mstch/mstch.hpp b/lib/mstch/include/mstch/mstch.hpp
new file mode 100644
index 0000000..58d3330
--- /dev/null
+++ b/lib/mstch/include/mstch/mstch.hpp
@@ -0,0 +1,113 @@
+#pragma once
+
+#include <vector>
+#include <map>
+#include <string>
+#include <memory>
+#include <functional>
+
+#include <boost/variant.hpp>
+
+namespace mstch {
+
+struct config {
+  static std::function<std::string(const std::string&)> escape;
+};
+
+namespace internal {
+
+template<class N>
+class object_t {
+ public:
+  const N& at(const std::string& name) const {
+    cache[name] = (methods.at(name))();
+    return cache[name];
+  }
+
+  bool has(const std::string name) const {
+    return methods.count(name) != 0;
+  }
+
+ protected:
+  template<class S>
+  void register_methods(S* s, std::map<std::string,N(S::*)()> methods) {
+    for(auto& item: methods)
+      this->methods.insert({item.first, std::bind(item.second, s)});
+  }
+
+ private:
+  std::map<std::string, std::function<N()>> methods;
+  mutable std::map<std::string, N> cache;
+};
+
+template<class T, class N>
+class is_fun {
+ private:
+  using not_fun = char;
+  using fun_without_args = char[2];
+  using fun_with_args = char[3];
+  template <typename U, U> struct really_has;
+  template <typename C> static fun_without_args& test(
+      really_has<N(C::*)() const, &C::operator()>*);
+  template <typename C> static fun_with_args& test(
+      really_has<N(C::*)(const std::string&) const,
+      &C::operator()>*);
+  template <typename> static not_fun& test(...);
+
+ public:
+  static bool const no_args = sizeof(test<T>(0)) == sizeof(fun_without_args);
+  static bool const has_args = sizeof(test<T>(0)) == sizeof(fun_with_args);
+};
+
+template<class N>
+using node_renderer = std::function<std::string(const N& n)>;
+
+template<class N>
+class lambda_t {
+ public:
+  template<class F>
+  lambda_t(F f, typename std::enable_if<is_fun<F, N>::no_args>::type* = 0):
+      fun([f](node_renderer<N> renderer, const std::string&) {
+        return renderer(f());
+      })
+  {
+  }
+
+  template<class F>
+  lambda_t(F f, typename std::enable_if<is_fun<F, N>::has_args>::type* = 0):
+      fun([f](node_renderer<N> renderer, const std::string& text) {
+        return renderer(f(text));
+      })
+  {
+  }
+
+  std::string operator()(node_renderer<N> renderer,
+      const std::string& text = "") const
+  {
+    return fun(renderer, text);
+  }
+
+ private:
+  std::function<std::string(node_renderer<N> renderer, const std::string&)> fun;
+};
+
+}
+
+using node = boost::make_recursive_variant<
+    std::nullptr_t, std::string, int, double, bool,
+    internal::lambda_t<boost::recursive_variant_>,
+    std::shared_ptr<internal::object_t<boost::recursive_variant_>>,
+    std::map<const std::string, boost::recursive_variant_>,
+    std::vector<boost::recursive_variant_>>::type;
+using object = internal::object_t<node>;
+using lambda = internal::lambda_t<node>;
+using map = std::map<const std::string, node>;
+using array = std::vector<node>;
+
+std::string render(
+    const std::string& tmplt,
+    const node& root,
+    const std::map<std::string,std::string>& partials =
+        std::map<std::string,std::string>());
+
+}