3 files changed, 39 insertions, 13 deletions
diff --git a/src/pkg/strings/reader.go b/src/pkg/strings/reader.go
index 10b0278e1..8423f7e45 100644
--- a/src/pkg/strings/reader.go
+++ b/src/pkg/strings/reader.go
@@ -49,7 +49,7 @@ func (r *Reader) ReadByte() (b byte, err os.Error) {
 // read yet.
 func (r *Reader) UnreadByte() os.Error {
 	if r.i <= 0 {
-		return os.ErrorString("strings.Reader: at beginning of string")
+		return os.NewError("strings.Reader: at beginning of string")
 	}
 	r.i--
 	r.prevRune = -1
@@ -80,7 +80,7 @@ func (r *Reader) ReadRune() (rune int, size int, err os.Error) {
 // The last method called on r must have been ReadRune.
 func (r *Reader) UnreadRune() os.Error {
 	if r.prevRune < 0 {
-		return os.ErrorString("strings.Reader: previous operation was not ReadRune")
+		return os.NewError("strings.Reader: previous operation was not ReadRune")
 	}
 	r.i = r.prevRune
 	r.prevRune = -1
diff --git a/src/pkg/strings/strings.go b/src/pkg/strings/strings.go
index bfd057180..6afbc7dc2 100644
--- a/src/pkg/strings/strings.go
+++ b/src/pkg/strings/strings.go
@@ -198,26 +198,40 @@ func genSplit(s, sep string, sepSave, n int) []string {
 	return a[0 : na+1]
 }
 
-// Split slices s into substrings separated by sep and returns a slice of
+// SplitN slices s into substrings separated by sep and returns a slice of
 // the substrings between those separators.
-// If sep is empty, Split splits after each UTF-8 sequence.
+// If sep is empty, SplitN splits after each UTF-8 sequence.
 // The count determines the number of substrings to return:
 //   n > 0: at most n substrings; the last substring will be the unsplit remainder.
 //   n == 0: the result is nil (zero substrings)
 //   n < 0: all substrings
-func Split(s, sep string, n int) []string { return genSplit(s, sep, 0, n) }
+func SplitN(s, sep string, n int) []string { return genSplit(s, sep, 0, n) }
 
-// SplitAfter slices s into substrings after each instance of sep and
+// SplitAfterN slices s into substrings after each instance of sep and
 // returns a slice of those substrings.
-// If sep is empty, Split splits after each UTF-8 sequence.
+// If sep is empty, SplitAfterN splits after each UTF-8 sequence.
 // The count determines the number of substrings to return:
 //   n > 0: at most n substrings; the last substring will be the unsplit remainder.
 //   n == 0: the result is nil (zero substrings)
 //   n < 0: all substrings
-func SplitAfter(s, sep string, n int) []string {
+func SplitAfterN(s, sep string, n int) []string {
 	return genSplit(s, sep, len(sep), n)
 }
 
+// Split slices s into all substrings separated by sep and returns a slice of
+// the substrings between those separators.
+// If sep is empty, Split splits after each UTF-8 sequence.
+// It is equivalent to SplitN with a count of -1.
+func Split(s, sep string) []string { return genSplit(s, sep, 0, -1) }
+
+// SplitAfter slices s into all substrings after each instance of sep and
+// returns a slice of those substrings.
+// If sep is empty, SplitAfter splits after each UTF-8 sequence.
+// It is equivalent to SplitAfterN with a count of -1.
+func SplitAfter(s, sep string) []string {
+	return genSplit(s, sep, len(sep), -1)
+}
+
 // Fields splits the string s around each instance of one or more consecutive white space
 // characters, returning an array of substrings of s or an empty list if s contains only white space.
 func Fields(s string) []string {
diff --git a/src/pkg/strings/strings_test.go b/src/pkg/strings/strings_test.go
index a1a635ddd..c54617339 100644
--- a/src/pkg/strings/strings_test.go
+++ b/src/pkg/strings/strings_test.go
@@ -186,7 +186,7 @@ var explodetests = []ExplodeTest{
 
 func TestExplode(t *testing.T) {
 	for _, tt := range explodetests {
-		a := Split(tt.s, "", tt.n)
+		a := SplitN(tt.s, "", tt.n)
 		if !eq(a, tt.a) {
 			t.Errorf("explode(%q, %d) = %v; want %v", tt.s, tt.n, a, tt.a)
 			continue
@@ -223,7 +223,7 @@ var splittests = []SplitTest{
 
 func TestSplit(t *testing.T) {
 	for _, tt := range splittests {
-		a := Split(tt.s, tt.sep, tt.n)
+		a := SplitN(tt.s, tt.sep, tt.n)
 		if !eq(a, tt.a) {
 			t.Errorf("Split(%q, %q, %d) = %v; want %v", tt.s, tt.sep, tt.n, a, tt.a)
 			continue
@@ -235,6 +235,12 @@ func TestSplit(t *testing.T) {
 		if s != tt.s {
 			t.Errorf("Join(Split(%q, %q, %d), %q) = %q", tt.s, tt.sep, tt.n, tt.sep, s)
 		}
+		if tt.n < 0 {
+			b := Split(tt.s, tt.sep)
+			if !reflect.DeepEqual(a, b) {
+				t.Errorf("Split disagrees with SplitN(%q, %q, %d) = %v; want %v", tt.s, tt.sep, tt.n, b, a)
+			}
+		}
 	}
 }
 
@@ -256,7 +262,7 @@ var splitaftertests = []SplitTest{
 
 func TestSplitAfter(t *testing.T) {
 	for _, tt := range splitaftertests {
-		a := SplitAfter(tt.s, tt.sep, tt.n)
+		a := SplitAfterN(tt.s, tt.sep, tt.n)
 		if !eq(a, tt.a) {
 			t.Errorf(`Split(%q, %q, %d) = %v; want %v`, tt.s, tt.sep, tt.n, a, tt.a)
 			continue
@@ -265,6 +271,12 @@ func TestSplitAfter(t *testing.T) {
 		if s != tt.s {
 			t.Errorf(`Join(Split(%q, %q, %d), %q) = %q`, tt.s, tt.sep, tt.n, tt.sep, s)
 		}
+		if tt.n < 0 {
+			b := SplitAfter(tt.s, tt.sep)
+			if !reflect.DeepEqual(a, b) {
+				t.Errorf("SplitAfter disagrees with SplitAfterN(%q, %q, %d) = %v; want %v", tt.s, tt.sep, tt.n, b, a)
+			}
+		}
 	}
 }
 
@@ -623,8 +635,8 @@ func equal(m string, s1, s2 string, t *testing.T) bool {
 	if s1 == s2 {
 		return true
 	}
-	e1 := Split(s1, "", -1)
-	e2 := Split(s2, "", -1)
+	e1 := Split(s1, "")
+	e2 := Split(s2, "")
 	for i, c1 := range e1 {
 		if i > len(e2) {
 			break