add time.parse_iso

vlib/time/time.v

@@ -320,6 +320,22 @@ pub fn parse(s string) Time {
 	})
 }
 
+// `parse_iso` parses time in the following format: "Thu, 12 Dec 2019 06:07:45 GMT"
+pub fn parse_iso(s string) Time {
+	fields := s.split(' ')
+	if fields.len < 5 {
+		return Time{}
+	}
+
+	pos := months_string.index(fields[2]) or { return Time{} }
+	mm := pos/3 + 1
+
+	tmstr := malloc(s.len*2)
+	count := int(C.sprintf(charptr(tmstr), '%s-%02d-%s %s'.str,
+		fields[3].str, mm, fields[1].str, fields[4].str))
+	return parse(tos(tmstr, count))
+}
+
 pub fn new_time(t Time) Time {
 	return {
 		t |

vlib/time/time_test.v

@@ -185,3 +185,19 @@ fn test_parse() {
 	    && t.hour == 12 && t.minute == 48 && t.second == 34
 }
 
+fn test_parse_iso() {
+	s1 := 'Thu, 12 Dec 2019 06:07:45 GMT'
+	t1 := time.parse_iso(s1)
+	assert t1.year == 2019 && t1.month == 12 && t1.day == 12
+	    && t1.hour == 6 && t1.minute == 7 && t1.second == 45
+
+	s2 := 'Thu 12 Dec 2019 06:07:45 +0800'
+	t2 := time.parse_iso(s2)
+	assert t2.year == 2019 && t2.month == 12 && t2.day == 12
+	    && t2.hour == 6 && t2.minute == 7 && t2.second == 45
+
+	s3 := 'Thu 12 Foo 2019 06:07:45 +0800'
+	t3 := time.parse_iso(s3)
+	assert t3.year == 0 && t3.month == 0 && t3.day == 0
+	    && t3.hour == 0 && t3.minute == 0 && t3.second == 0
+}