feat: add iterator

reader_test.go

@@ -0,0 +1,42 @@
+package spb
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"testing"
+)
+
+func TestReader(t *testing.T) {
+	f, err := os.Open("dict.sp")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+	ft, err := os.Open("dict.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer ft.Close()
+	sc := bufio.NewScanner(ft)
+	var s Iterator
+	i := 1
+	for sc.Scan() {
+		s, err = NewReader(f)
+		if err != nil {
+			break
+		}
+		if !s.Next() {
+			t.Fatal("unexpected no next")
+		}
+		t0 := s.String()
+		if !s.Next() {
+			t.Fatal("unexpected no next")
+		}
+		t1 := s.String()
+		if fmt.Sprint(t0, "\t", t1) != sc.Text() {
+			t.Fatal("invalid text @ line", i)
+		}
+		i++
+	}
+}