add sort function

README.md

@@ -99,12 +99,12 @@ Variables are rendered within the `{{ ... }}` expressions.
 ```c++
 json data;
 data["neighbour"] = "Peter";
-data["guests"] = {"Jeff", "Patrick", "Tom"};
+data["guests"] = {"Jeff", "Tom", "Patrick"};
 data["time"]["start"] = 16;
 data["time"]["end"] = 22;
 
 // Indexing in array
-render("{{ guests/1 }}", data); // "Patrick"
+render("{{ guests/1 }}", data); // "Tom"
 
 // Objects
 render("{{ time/start }} to {{ time/end }}pm"); // "16 to 22pm"
@@ -127,8 +127,8 @@ render(R"(Guest List:
 
 /* Guest List:
 	1: Jeff
-	2: Pierre
-	3: Tom */
+	2: Tom
+	3: Patrick */
 ```
 In a loop, the special variables `index (number)`, `index1 (number)`, `is_first (boolean)` and `is_last (boolean)` are available. You can also iterate over objects like `{% for key, value in time %}`.
 
@@ -172,7 +172,12 @@ render("I count {{ length(guests) }} guests.", data); // "I count 3 guests."
 
 // Get first and last element in a list
 render("{{ first(guests) }} was first.", data); // "Jeff was first."
-render("{{ last(guests) }} was last.", data); // "Tom was last."
+render("{{ last(guests) }} was last.", data); // "Patir was last."
+
+// Sort a list
+render("{{ sort([3,2,1]) }}", data); // "[1,2,3]"
+render("{{ sort(guests) }}", data); // "[\"Jeff\", \"Patrick\", \"Tom\"]"
+
 
 // Round numbers to a given precision
 render("{{ round(3.1415, 0) }}", data); // 3

src/inja.hpp

@@ -12,6 +12,8 @@
 #include <iostream>
 #include <locale>
 #include <regex>
+#include <vector>
+#include <algorithm>
 #include <type_traits>
 
 
@@ -242,6 +244,7 @@ struct Parsed {
 		Lower,
 		Range,
 		Length,
+		Sort,
 		First,
 		Last,
 		Round,
@@ -372,6 +375,11 @@ public:
 				const std::vector<json> list = eval_expression<std::vector<json>>(element.args[0], data);
 				return list.size();
 			}
+			case Parsed::Function::Sort: {
+				std::vector<json> list = eval_expression<std::vector<json>>(element.args[0], data);
+				std::sort(list.begin(), list.end());
+				return list;
+			}
 			case Parsed::Function::First: {
 				const std::vector<json> list = eval_expression<std::vector<json>>(element.args[0], data);
 				return list.front();
@@ -605,6 +613,7 @@ public:
 		{Parsed::Function::Lower, function_regex("lower", 1)},
 		{Parsed::Function::Range, function_regex("range", 1)},
 		{Parsed::Function::Length, function_regex("length", 1)},
+		{Parsed::Function::Sort, function_regex("sort", 1)},
 		{Parsed::Function::First, function_regex("first", 1)},
 		{Parsed::Function::Last, function_regex("last", 1)},
 		{Parsed::Function::Round, function_regex("round", 2)},

test/src/unit-renderer.cpp

@@ -107,6 +107,12 @@ TEST_CASE("functions") {
 		// CHECK_THROWS_WITH( env.render("{{ length(5) }}", data), "[json.exception.type_error.302] type must be array, but is number" );
 	}
 
+	SECTION("sort") {
+		CHECK( env.render("{{ sort([3, 2, 1]) }}", data) == "[1,2,3]" );
+		CHECK( env.render("{{ sort([\"bob\", \"charlie\", \"alice\"]) }}", data) == "[\"alice\",\"bob\",\"charlie\"]" );
+		// CHECK_THROWS_WITH( env.render("{{ sort(5) }}", data), "[json.exception.type_error.302] type must be array, but is number" );
+	}
+
 	SECTION("first") {
 		CHECK( env.render("{{ first(names) }}", data) == "Jeff" );
 		// CHECK_THROWS_WITH( env.render("{{ length(5) }}", data), "[json.exception.type_error.302] type must be array, but is number" );