feat: lines from reader iterator shouldn't strip whitespace

constructor.go

@@ -265,18 +265,24 @@ func (Handlers) StrSliceConcatinate(input []string) Future[string] {
 func (Handlers) Stringer(op fmt.Stringer) Future[string] { return op.String }
 
 // Lines provides a fun.Iterator access over the contexts of a
-// (presumably plaintext) io.Reader, using the bufio.Scanner. During
-// iteration the leading and trailing space is also trimmed.
+// (presumably plaintext) io.Reader, using the bufio.Scanner.
 func (Handlers) Lines(reader io.Reader) *Iterator[string] {
 	scanner := bufio.NewScanner(reader)
 	return Generator(func(ctx context.Context) (string, error) {
 		if !scanner.Scan() {
 			return "", ers.Join(io.EOF, scanner.Err())
 		}
-		return strings.TrimSpace(scanner.Text()), nil
+		return scanner.Text(), nil
 	})
 }
 
+// LinesWithSpaceTrimed provides an iterator with access to the
+// line-separated content of an io.Reader, line Lines(), but with the
+// leading and trailing space trimmed from each line.
+func (Handlers) LinesWithSpaceTrimed(reader io.Reader) *Iterator[string] {
+	return HF.Lines(reader).Transform(Converter(strings.TrimSpace))
+}
+
 // Itoa produces a Transform function that converts integers into
 // strings.
 func (Handlers) Itoa() Transform[int, string] {

constructor_test.go

@@ -216,7 +216,7 @@ func TestHandlers(t *testing.T) {
 		ctx, cancel := context.WithCancel(context.Background())
 		defer cancel()
 		var prev string
-		check.NotError(t, HF.Lines(buf).Observe(func(line string) {
+		check.NotError(t, HF.LinesWithSpaceTrimed(buf).Observe(func(line string) {
 			count++
 			assert.Equal(t, len(line), 64)
 			assert.NotEqual(t, prev, line)

itertool/itertool.go

@@ -299,7 +299,7 @@ func Monotonic(max int) *fun.Iterator[int] { return fun.HF.Counter(max) }
 // documents into objects in the form of an iterator.
 func JSON[T any](in io.Reader) *fun.Iterator[T] {
 	var zero T
-	return fun.ConvertIterator(fun.HF.Lines(in), fun.ConverterErr(func(in string) (out T, err error) {
+	return fun.ConvertIterator(fun.HF.LinesWithSpaceTrimed(in), fun.ConverterErr(func(in string) (out T, err error) {
 		defer func() { err = ers.Join(err, ers.ParsePanic(recover())) }()
 		if err = json.Unmarshal([]byte(in), &out); err != nil {
 			return zero, err