string.split_nth - return the rest of the string as the last value in the result array

vlib/builtin/string.v

@@ -402,6 +402,12 @@ pub fn (s string) split(delim string) []string {
 	return s.split_nth(delim, 0)
 }
 
+/*
+split_nth - splits the string based on the passed `delim` substring. 
+It returns the first Nth parts. When N=0, return all the splits. 
+The last returned element has the remainder of the string, even if
+the remainder contains more `delim` substrings.
+*/
 pub fn (s string) split_nth(delim string, nth int) []string {
 	mut res := []string
 	mut i := 0
@@ -418,6 +424,7 @@ pub fn (s string) split_nth(delim string, nth int) []string {
 		return res
 	}
 	mut start := 0
+	nth_1 := nth - 1
 	for i <= s.len {
 		mut is_delim := s[i] == delim[0]
 		mut j := 0
@@ -425,10 +432,6 @@ pub fn (s string) split_nth(delim string, nth int) []string {
 			is_delim = is_delim && s[i + j] == delim[j]
 			j++
 		}
-		was_last := nth > 0 && res.len == nth
-		if was_last {
-			break
-		}
 		last := i == s.len - 1
 		if is_delim || last {
 			if !is_delim && last {
@@ -438,6 +441,13 @@ pub fn (s string) split_nth(delim string, nth int) []string {
 			if val.starts_with(delim) {
 				val = val.right(delim.len)
 			}
+
+			was_last := nth > 0 && res.len == nth_1
+			if was_last {
+				res << s.right(start)
+				break
+			}
+			
 			res << val
 			start = i + delim.len
 		}

vlib/builtin/string_test.v

@@ -121,6 +121,32 @@ fn test_split_nth() {
 	assert (e.split_nth(',', 3).len == 3)
 }
 
+fn test_split_nth_values() {
+	line := 'CMD=eprintln(phase=1)'
+	
+	a0 := line.split_nth('=', 0)
+	assert a0.len == 3
+	assert a0[0] == 'CMD'
+	assert a0[1] == 'eprintln(phase'
+	assert a0[2] == '1)'
+
+	a1 := line.split_nth('=', 1)
+	assert a1.len == 1
+	assert a1[0] == 'CMD=eprintln(phase=1)'
+
+	a2 := line.split_nth('=', 2)
+	assert a2.len == 2
+	assert a2[0] == 'CMD'
+	assert a2[1] == 'eprintln(phase=1)'
+
+	a3 := line.split_nth('=', 3)
+	assert a3.len == 3
+	assert a3[0] == 'CMD'
+	assert a3[1] == 'eprintln(phase'
+	assert a3[2] == '1)'
+	
+}
+
 fn test_split() {
 	mut s := 'volt/twitch.v:34'
 	mut vals := s.split(':')