Add real-number version of parse_range

Also use it in the Lua API.

src/scripting/lua_stringx.cpp

@@ -327,13 +327,20 @@ static int intf_str_format(lua_State* L)
 /**
  * Parses a range string of the form a-b into an interval pair
  * Accepts the string "infinity" as representing a Very Large Number
+ * Arg 2: (optional) If true, parse as real numbers instead of integers
  */
 static int intf_parse_range(lua_State* L)
 {
 	const std::string str = luaL_checkstring(L, 1);
-	auto interval = utils::parse_range(str);
-	lua_pushnumber(L, interval.first);
-	lua_pushnumber(L, interval.second);
+	if(luaL_opt(L, lua_toboolean, 2, false)) {
+		auto interval = utils::parse_range_real(str);
+		lua_pushnumber(L, interval.first);
+		lua_pushnumber(L, interval.second);
+	} else {
+		auto interval = utils::parse_range(str);
+		lua_pushinteger(L, interval.first);
+		lua_pushinteger(L, interval.second);
+	}
 	return 2;
 }
 

src/serialization/string_utils.cpp

@@ -845,6 +845,29 @@ std::pair<int, int> parse_range(const std::string& str)
 	return res;
 }
 
+std::pair<double, double> parse_range_real(const std::string& str)
+{
+	const std::string::const_iterator dash = std::find(str.begin(), str.end(), '-');
+	const std::string a(str.begin(), dash);
+	const std::string b = dash != str.end() ? std::string(dash + 1, str.end()) : a;
+	std::pair<double,double> res {0,0};
+	try {
+		if(b == "infinity") {
+			res = std::pair(std::stod(a), std::numeric_limits<double>::infinity());
+		} else {
+			res = std::pair(std::stod(a), std::stod(b));
+		}
+
+		if(res.second < res.first) {
+			res.second = res.first;
+		}
+	} catch(const std::invalid_argument&) {
+		ERR_GENERAL << "Invalid range: "<< str;
+	}
+
+	return res;
+}
+
 std::vector<std::pair<int, int>> parse_ranges(const std::string& str)
 {
 	std::vector<std::pair<int, int>> to_return;
@@ -855,6 +878,16 @@ std::vector<std::pair<int, int>> parse_ranges(const std::string& str)
 	return to_return;
 }
 
+std::vector<std::pair<double, double>> parse_ranges_real(const std::string& str)
+{
+	std::vector<std::pair<double, double>> to_return;
+	for(const std::string& r : utils::split(str)) {
+		to_return.push_back(parse_range_real(r));
+	}
+
+	return to_return;
+}
+
 void ellipsis_truncate(std::string& str, const std::size_t size)
 {
 	const std::size_t prev_size = str.length();

src/serialization/string_utils.hpp

@@ -286,6 +286,10 @@ std::pair<int, int> parse_range(const std::string& str);
 
 std::vector<std::pair<int, int>> parse_ranges(const std::string& str);
 
+std::pair<double, double> parse_range_real(const std::string& str);
+
+std::vector<std::pair<double, double>> parse_ranges_real(const std::string& str);
+
 int apply_modifier(const int number, const std::string &amount, const int minimum = 0);
 
 /** Add a "+" or replace the "-" par Unicode minus */