Add capitalize function

README.md

@@ -206,9 +206,10 @@ Assignments only set the value within the rendering context; they do not modify
 
 A few functions are implemented within the inja template syntax. They can be called with
 ```.cpp
-// Upper and lower function, for string cases
+// Upper, lower and capitalize function, for string cases
 render("Hello {{ upper(neighbour) }}!", data); // "Hello PETER!"
 render("Hello {{ lower(neighbour) }}!", data); // "Hello peter!"
+render("Hello {{ capitalize(neighbour) }}!", data); // "Hello Peter!"
 
 // Range function, useful for loops
 render("{% for i in range(4) %}{{ loop.index1 }}{% endfor %}", data); // "1234"

include/inja/function_storage.hpp

@@ -34,6 +34,7 @@ class FunctionStorage {
     Modulo,
     AtId,
     At,
+    Capitalize,
     Default,
     DivisibleBy,
     Even,
@@ -76,6 +77,7 @@ class FunctionStorage {
 
   std::map<std::pair<std::string, int>, FunctionData> function_storage = {
       {std::make_pair("at", 2), FunctionData {Operation::At}},
+      {std::make_pair("capitalize", 1), FunctionData {Operation::Capitalize}},
       {std::make_pair("default", 2), FunctionData {Operation::Default}},
       {std::make_pair("divisibleBy", 2), FunctionData {Operation::DivisibleBy}},
       {std::make_pair("even", 1), FunctionData {Operation::Even}},

include/inja/renderer.hpp

@@ -309,6 +309,12 @@ class Renderer : public NodeVisitor {
         data_eval_stack.push(&args[0]->at(args[1]->get<int>()));
       }
     } break;
+    case Op::Capitalize: {
+      auto result = get_arguments<1>(node)[0]->get<json::string_t>();
+      result[0] = static_cast<char>(::toupper(result[0]));
+      std::transform(result.begin() + 1, result.end(), result.begin() + 1, [](char c) { return static_cast<char>(::tolower(c)); });
+      make_result(std::move(result));
+    } break;
     case Op::Default: {
       const auto test_arg = get_arguments<1, 0, false>(node)[0];
       data_eval_stack.push(test_arg ? test_arg : get_arguments<1, 1>(node)[0]);

single_include/inja/inja.hpp

@@ -123,6 +123,7 @@ class FunctionStorage {
     Modulo,
     AtId,
     At,
+    Capitalize,
     Default,
     DivisibleBy,
     Even,
@@ -165,6 +166,7 @@ class FunctionStorage {
 
   std::map<std::pair<std::string, int>, FunctionData> function_storage = {
       {std::make_pair("at", 2), FunctionData {Operation::At}},
+      {std::make_pair("capitalize", 1), FunctionData {Operation::Capitalize}},
       {std::make_pair("default", 2), FunctionData {Operation::Default}},
       {std::make_pair("divisibleBy", 2), FunctionData {Operation::DivisibleBy}},
       {std::make_pair("even", 1), FunctionData {Operation::Even}},
@@ -2378,6 +2380,12 @@ class Renderer : public NodeVisitor {
         data_eval_stack.push(&args[0]->at(args[1]->get<int>()));
       }
     } break;
+    case Op::Capitalize: {
+      auto result = get_arguments<1>(node)[0]->get<json::string_t>();
+      result[0] = std::toupper(result[0]);
+      std::transform(result.begin() + 1, result.end(), result.begin() + 1, [](char c) { return static_cast<char>(::tolower(c)); });
+      make_result(std::move(result));
+    } break;
     case Op::Default: {
       const auto test_arg = get_arguments<1, 0, false>(node)[0];
       data_eval_stack.push(test_arg ? test_arg : get_arguments<1, 1>(node)[0]);

test/test-functions.cpp

@@ -58,6 +58,11 @@ TEST_CASE("functions") {
     // [json.exception.type_error.302] type must be string, but is number" );
   }
 
+  SUBCASE("capitalize") {
+    CHECK(env.render("{{ capitalize(name) }}", data) == "Peter");
+    CHECK(env.render("{{ capitalize(city) }}", data) == "New york");
+  }
+
   SUBCASE("range") {
     CHECK(env.render("{{ range(2) }}", data) == "[0,1]");
     CHECK(env.render("{{ range(4) }}", data) == "[0,1,2,3]");