diff --git a/include/inja/environment.hpp b/include/inja/environment.hpp
index cbcc82e..72b312b 100644
--- a/include/inja/environment.hpp
+++ b/include/inja/environment.hpp
@@ -106,6 +106,10 @@ public:
     return result;
   }
 
+  Template parse_file(const std::string &filename) {
+    return parse_template(filename);
+  }
+
   std::string render(nonstd::string_view input, const json &data) { return render(parse(input), data); }
 
   std::string render(const Template &tmpl, const json &data) {
diff --git a/include/inja/node.hpp b/include/inja/node.hpp
index 326c454..62707f8 100644
--- a/include/inja/node.hpp
+++ b/include/inja/node.hpp
@@ -47,7 +47,9 @@ public:
   virtual void visit(const IncludeStatementNode& node) = 0;
 };
 
-
+/*!
+ * \brief Base node class for the abstract syntax tree (AST).
+ */
 class AstNode {
 public:
   virtual void accept(NodeVisitor& v) const = 0;
diff --git a/include/inja/parser.hpp b/include/inja/parser.hpp
index 682a069..ae7b7a1 100644
--- a/include/inja/parser.hpp
+++ b/include/inja/parser.hpp
@@ -75,12 +75,6 @@ class Parser {
     current_expression_list->rpn_output.emplace_back(std::make_shared<LiteralNode>(json::parse(json_text), json_text.data() - content_ptr));
   }
 
-
-public:
-  explicit Parser(const ParserConfig &parser_config, const LexerConfig &lexer_config,
-                  TemplateStorage &template_storage, const FunctionStorage &function_storage)
-      : config(parser_config), lexer(lexer_config), template_storage(template_storage), function_storage(function_storage) { }
-
   bool parse_expression(Template &tmpl, Token::Kind closing) {
     while (tok.kind != closing && tok.kind != Token::Kind::Eof) {
       // Literals
@@ -521,6 +515,12 @@ public:
     }
   }
 
+
+public:
+  explicit Parser(const ParserConfig &parser_config, const LexerConfig &lexer_config,
+                  TemplateStorage &template_storage, const FunctionStorage &function_storage)
+      : config(parser_config), lexer(lexer_config), template_storage(template_storage), function_storage(function_storage) { }
+
   Template parse(nonstd::string_view input, nonstd::string_view path) {
     auto result = Template(static_cast<std::string>(input));
     parse_into(result, path);
diff --git a/include/inja/renderer.hpp b/include/inja/renderer.hpp
index 21bea51..9a4dae0 100644
--- a/include/inja/renderer.hpp
+++ b/include/inja/renderer.hpp
@@ -140,10 +140,6 @@ class Renderer : public NodeVisitor  {
     return result;
   }
 
-public:
-  Renderer(const RenderConfig& config, const TemplateStorage &template_storage, const FunctionStorage &function_storage)
-      : config(config), template_storage(template_storage), function_storage(function_storage) { }
-
   void visit(const BlockNode& node) {
     for (auto& n : node.nodes) {
       n->accept(*this);
@@ -567,6 +563,10 @@ public:
     }
   }
 
+public:
+  Renderer(const RenderConfig& config, const TemplateStorage &template_storage, const FunctionStorage &function_storage)
+      : config(config), template_storage(template_storage), function_storage(function_storage) { }
+
   void render_to(std::ostream &os, const Template &tmpl, const json &data, json *loop_data = nullptr) {
     output_stream = &os;
     current_template = &tmpl;
diff --git a/include/inja/statistics.hpp b/include/inja/statistics.hpp
index c0c33e1..c8be1b3 100644
--- a/include/inja/statistics.hpp
+++ b/include/inja/statistics.hpp
@@ -11,11 +11,7 @@ namespace inja {
 /*!
  * \brief A class for counting statistics on a Template.
  */
-struct StatisticsVisitor : public NodeVisitor {
-  unsigned int variable_counter;
-
-  explicit StatisticsVisitor() : variable_counter(0) { }
-
+class StatisticsVisitor : public NodeVisitor {
   void visit(const BlockNode& node) {
     for (auto& n : node.nodes) {
       n->accept(*this);
@@ -58,6 +54,11 @@ struct StatisticsVisitor : public NodeVisitor {
   }
 
   void visit(const IncludeStatementNode&) { }
+
+public:
+  unsigned int variable_counter;
+
+  explicit StatisticsVisitor() : variable_counter(0) { }
 };
 
 } // namespace inja
diff --git a/test/test-renderer.cpp b/test/test-renderer.cpp
index 51bc350..a25694e 100644
--- a/test/test-renderer.cpp
+++ b/test/test-renderer.cpp
@@ -74,8 +74,7 @@ TEST_CASE("types") {
   }
 
   SUBCASE("nested loops") {
-    auto ldata = json::parse(
-        R"DELIM(
+    auto ldata = json::parse(R""""(
 { "outer" : [
     { "inner" : [
         { "in2" : [ 1, 2 ] },
@@ -91,13 +90,13 @@ TEST_CASE("types") {
     }
     ]
 }
-)DELIM");
+)"""");
 
-    CHECK(env.render(R"DELIM(
+    CHECK(env.render(R""""(
 {% for o in outer %}{% for i in o.inner %}{{loop.parent.index}}:{{loop.index}}::{{loop.parent.is_last}}
 {% for ii in i.in2%}{{ii}},{%endfor%}
 {%endfor%}{%endfor%}
-)DELIM",
+)"""",
                      ldata) == "\n0:0::false\n1,2,\n0:1::false\n\n0:2::false\n\n2:0::true\n3,4,\n2:1::true\n5,6,\n\n");
   }
 
@@ -124,19 +123,19 @@ TEST_CASE("types") {
   }
 
   SUBCASE("line statements") {
-    CHECK(env.render(R"(## if is_happy
+    CHECK(env.render(R""""(## if is_happy
 Yeah!
-## endif)",
-                     data) == R"(Yeah!
-)");
+## endif)"""",
+                     data) == R""""(Yeah!
+)"""");
 
-    CHECK(env.render(R"(## if is_happy
+    CHECK(env.render(R""""(## if is_happy
 ## if is_happy
 Yeah!
 ## endif
-## endif    )",
-                     data) == R"(Yeah!
-)");
+## endif    )"""",
+                     data) == R""""(Yeah!
+)"""");
   }
 }
 
@@ -253,11 +252,11 @@ TEST_CASE("other syntax") {
     env.set_line_statement("$$");
     env.set_expression("<%", "%>");
 
-    std::string string_template = R"DELIM(Hello <%name%>
+    std::string string_template = R""""(Hello <%name%>
 $$ if name == "Peter"
     You really are <%name%>
 $$ endif
-)DELIM";
+)"""";
 
     CHECK(env.render(string_template, data) == "Hello Peter\n    You really are Peter\n");
   }
diff --git a/test/test-units.cpp b/test/test-units.cpp
index 074484d..3a8c82b 100644
--- a/test/test-units.cpp
+++ b/test/test-units.cpp
@@ -5,13 +5,13 @@
 
 
 TEST_CASE("source location") {
-  std::string content = R"DELIM(Lorem Ipsum
+  std::string content = R""""(Lorem Ipsum
   Dolor
 Amid
 Set ().$
 Try this
 
-)DELIM";
+)"""";
 
   CHECK(inja::get_source_location(content, 0).line == 1);
   CHECK(inja::get_source_location(content, 0).column == 1);