Add option to set step length when specifying list of time with keys 'hours' or 'times'

"hours" : "0-12-3" -> 0,3,6,9,12
"times" : "0:00:00-1:00:00-0:15:00" -> 0:00:00,0:15:00,0:30:00,0:45:00,1:00:00

Author: mpartio

doc/configuration.md

@@ -254,7 +254,7 @@ Multiple origin times can also be specified with key `origintimes`.
 
 <a name="Time_2"/>
 
-## Lead time method 1: Listing hours
+## Lead time method 1: Listing times
 
 With key `hours` the hours (lead times) that should be calculated are listed. Values are separated with a comma, if a hyphen ('-') is used, Himan will interpolate values to fill the gap.
 
@@ -266,6 +266,19 @@ Example:
 
 This example will result to hours 1,2,3,4,5,6,7 and 8.
 
+By default when expanding a list the step value is 1, but it can be changed:
+
+    "hours" : "1,2-8-2"
+
+Result: 1,2,4,6,8
+
+For sub-hour values key `times` can be used:
+
+    "times" : "0:00:00-9:00:00-0:15:00"
+
+Result: 0:00:00,0:15:00,0:30:00,...,9:00:00
+
+
 <a name="Time_3"/>
 
 ## Lead time method 2: Setting start and stop values
@@ -297,6 +310,13 @@ Example:
     "stop_minute" : "1470",
     "step" : "15",
 
+start_time and stop_time can be used to specify time duration value
+
+    "start_time" : "0:00:00",
+    "stop_time" : "1:00:00",
+    "step" : "0:15:00"
+
+
 <a name="Levels"/>
 
 # Levels

himan-lib/include/util.h

@@ -55,6 +55,7 @@ std::vector<T> Split(const std::string& s, const std::string& delims);
  */
 
 std::vector<int> ExpandString(const std::string& identifier);
+std::vector<time_duration> ExpandTimeDuration(const std::string& identifier);
 
 /**
  * @brief Join a string-vector with given delimiter

himan-lib/source/json_parser.cpp

@@ -765,14 +765,14 @@ void Steps(const boost::property_tree::ptree& pt, shared_ptr<configuration>& con
 
 	try
 	{
-		vector<string> timesStr = himan::util::Split(pt.get<string>("times"), ",");
+		vector<time_duration> timeValues = himan::util::ExpandTimeDuration(pt.get<string>("times"));
 		vector<forecast_time> times;
 
 		for (const auto& originDateTime : originDateTimes)
 		{
-			for (const auto& str : timesStr)
+			for (const auto& tv : timeValues)
 			{
-				times.push_back(forecast_time(originDateTime, time_duration(str)));
+				times.push_back(forecast_time(originDateTime, tv));
 			}
 		}
 		conf->Times(times);

himan-lib/source/util.cpp

@@ -180,16 +180,27 @@ vector<int> util::ExpandString(const std::string& identifier)
 	// 1,5,10-12
 	// --> return a vector of:
 	// 1,5,10,11,12
+	// 1,5,10-16-2
+	// --> return a vector of:
+	// 1,5,10,12,14,16
 
 	vector<int> ret;
 	const auto split1 = Split(identifier, ",");
 	for (const auto& tok : split1)
 	{
-		const auto split2 = Split<int>(tok, "-");
+		auto split2 = Split<int>(tok, "-");
+
+		int step = 1;
+
+		if (split2.size() == 3)
+		{
+			step = split2[2];
+			split2.pop_back();
+		}
 
 		if (split2.size() == 2)
 		{
-			int a = split2[0], b = split2[1], step = 1;
+			int a = split2[0], b = split2[1];
 			if (a > b)
 			{
 				step *= -1;
@@ -207,6 +218,45 @@ vector<int> util::ExpandString(const std::string& identifier)
 	return ret;
 }
 
+vector<time_duration> util::ExpandTimeDuration(const std::string& identifier)
+{
+	vector<time_duration> ret;
+	const auto split1 = Split(identifier, ",");
+	for (const auto& tok : split1)
+	{
+		auto split2 = Split<std::string>(tok, "-");
+
+		time_duration step = ONE_HOUR;
+
+		if (split2.size() == 3)
+		{
+			step = time_duration(split2[2]);
+			split2.pop_back();
+		}
+
+		if (split2.size() == 2)
+		{
+			time_duration a = split2[0], b = split2[1];
+			if (a > b)
+			{
+				step *= -1;
+			}
+
+			while (a != b)
+			{
+				ret.push_back(time_duration(a));
+				a += step;
+			}
+			ret.push_back(time_duration(a));  // include end range value
+		}
+		else if (split2.size() == 1)
+		{
+			ret.push_back(split2[0]);
+		}
+	}
+	return ret;
+}
+
 vector<string> util::Split(const string& s, const string& delims)
 {
 	return Split<std::string>(s, delims);