UnreadRunes implemented

errors.go

@@ -1,7 +1,7 @@
 package bufr
 
 import (
-	"git.tordarus.net/Tordarus/adverr"
+	"git.milar.in/milarin/adverr"
 )
 
 var (

go.mod

@@ -1,8 +1,8 @@
-module git.tordarus.net/Tordarus/bufr
+module git.milar.in/milarin/bufr
 
-go 1.18
+go 1.19
 
 require (
-	git.tordarus.net/Tordarus/adverr v0.2.0
-	git.tordarus.net/Tordarus/dstruct v0.0.2
+	git.milar.in/milarin/adverr v1.1.0
+	git.milar.in/milarin/ds v0.0.2
 )

go.sum

@@ -1,4 +1,8 @@
-git.tordarus.net/Tordarus/adverr v0.2.0 h1:kLYjR2/Vb2GHiSAMvAv+WPNaHR9BRphKanf8H/pCZdA=
-git.tordarus.net/Tordarus/adverr v0.2.0/go.mod h1:XRf0+7nhOkIEr0gi9DUG4RvV2KaOFB0fYPDaR1KLenw=
-git.tordarus.net/Tordarus/dstruct v0.0.2 h1:oFaZO7YXQeHjxL4DmMaZ+Eb4MvP23dX8GAXs0Z6VQKo=
-git.tordarus.net/Tordarus/dstruct v0.0.2/go.mod h1:RvLL2G4lUCGzwr8KaBGQRi3qlMG0WTgGhcVN6iyZZuw=
+git.milar.in/milarin/adverr v1.1.0 h1:jD9WnOvs40lfMhvqQ7cllOaRJNBMWr1f07/s9jAadp0=
+git.milar.in/milarin/adverr v1.1.0/go.mod h1:joU9sBb7ySyNv4SpTXB0Z4o1mjXsArBw4N27wjgzj9E=
+git.milar.in/milarin/ds v0.0.0-20230120204927-7dc44b9cd222 h1:r7gcMqltPqk9U2/+LzEN5dooZ5wiQ8C7SI/nK6T0KjA=
+git.milar.in/milarin/ds v0.0.0-20230120204927-7dc44b9cd222/go.mod h1:HJK7QERcRvV9j7xzEocrKUtW+1q4JB1Ly4Bj54chfwI=
+git.milar.in/milarin/ds v0.0.1 h1:ov4Rp+QiB3xtmV0a4eC+LluxWEOvbykgW+wCchYEp9o=
+git.milar.in/milarin/ds v0.0.1/go.mod h1:HJK7QERcRvV9j7xzEocrKUtW+1q4JB1Ly4Bj54chfwI=
+git.milar.in/milarin/ds v0.0.2 h1:vCA3mDxZUNfvHpzrdz7SeBUKiPn74NTopo915IUG7I0=
+git.milar.in/milarin/ds v0.0.2/go.mod h1:HJK7QERcRvV9j7xzEocrKUtW+1q4JB1Ly4Bj54chfwI=

pos_rune.go

@@ -0,0 +1,6 @@
+package bufr
+
+type posRune struct {
+	Rune rune
+	Pos  Position
+}

position.go

@@ -0,0 +1,17 @@
+package bufr
+
+type Position struct {
+	Index  int
+	Line   int
+	Column int
+}
+
+func (p *Position) Advance(rn rune) {
+	p.Index++
+	if rn == '\n' {
+		p.Line++
+		p.Column = 0
+	} else {
+		p.Column++
+	}
+}

reader.go

@@ -5,30 +5,75 @@ import (
 	"io"
 	"strings"
 
-	"git.tordarus.net/Tordarus/dstruct"
+	"git.milar.in/milarin/ds"
 )
 
 type Reader struct {
-	buf *dstruct.Stack[rune]
+	buf ds.Stack[posRune]
 	src *bufio.Reader
+	pos *Position
 }
 
 func NewReader(r io.Reader) *Reader {
 	return &Reader{
-		buf: new(dstruct.Stack[rune]),
+		buf: ds.NewArrayStack[posRune](),
 		src: bufio.NewReader(r),
+		pos: &Position{},
 	}
 }
 
+func (r *Reader) psrn(rn rune) posRune {
+	return posRune{
+		Rune: rn,
+		Pos:  *r.pos,
+	}
+}
+
+func (r *Reader) Pos() (index, line, column int) {
+	return r.pos.Index, r.pos.Line, r.pos.Column
+}
+
 // Rune returns the next rune in r
 func (r *Reader) Rune() (rune, error) {
 	rn, _, err := r.src.ReadRune()
 	if err == nil {
-		r.buf.Push(rn)
+		r.buf.Push(r.psrn(rn))
+		r.pos.Advance(rn)
 	}
 	return rn, err
 }
 
+// PeekRune returns the next rune in r without advancing reader position.
+// The next read will return the same rune again.
+func (r *Reader) PeekRune() (rune, error) {
+	rn, err := r.Rune()
+	if err != nil {
+		return 0, err
+	}
+
+	if err := r.UnreadRune(); err != nil {
+		return 0, err
+	}
+
+	return rn, nil
+}
+
+// String returns the next len runes in r as a string.
+// If an error occurs, both the already read string and the error will be returned
+func (r *Reader) String(len int) (string, error) {
+	str := ""
+
+	for i := 0; i < len; i++ {
+		rn, err := r.Rune()
+		if err != nil {
+			return str, err
+		}
+		str += string(rn)
+	}
+
+	return str, nil
+}
+
 // UnreadRune unreads the last rune.
 // The next read will include the unread rune.
 // It returns ErrNothingToUnread if there wasn't any read yet
@@ -38,9 +83,12 @@ func (r *Reader) UnreadRune() error {
 	}
 
 	if err := r.src.UnreadRune(); err == nil {
-		r.buf.Pop()
+		rn := r.buf.Pop()
+		*r.pos = rn.Pos
 	} else {
-		r.src = prependRune(r.buf.Pop(), r.src)
+		rn := r.buf.Pop()
+		*r.pos = rn.Pos
+		r.src = prependRune(rn.Rune, r.src)
 	}
 
 	return nil
@@ -60,6 +108,17 @@ func (r *Reader) UnreadString(str string) error {
 	return r.UnreadRune()
 }
 
+// UnreadRunes calls UnreadRune n times
+func (r *Reader) UnreadRunes(n int) error {
+	for i := 0; i < n; i++ {
+		err := r.UnreadRune()
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 // StringWhile reads runes and calls f for each one.
 // It returns all runes as a string for which f returned true.
 // It stops when f returns false or an error occured.
@@ -67,15 +126,50 @@ func (r *Reader) UnreadString(str string) error {
 func (r *Reader) StringWhile(f func(rn rune) bool) (string, error) {
 	s := new(strings.Builder)
 
+	var rn rune
 	var err error
-	for rn, err := r.Rune(); err == nil && f(rn); rn, err = r.Rune() {
+	for rn, err = r.Rune(); err == nil && f(rn); rn, err = r.Rune() {
 		s.WriteRune(rn)
 	}
 
 	return s.String(), err
 }
 
+// PeekStringWhile acts as StringWhile but does not advance reader position
+func (r *Reader) PeekStringWhile(f func(rn rune) bool) (string, error) {
+	str, err := r.StringWhile(f)
+	if err != nil {
+		return "", err
+	}
+
+	if err := r.UnreadString(str); err != nil {
+		return "", err
+	}
+
+	return str, nil
+}
+
 // StringUntil is a shorthand for r.StringWhile(func(rn rune) bool { return !f(rn) })
 func (r *Reader) StringUntil(f func(rn rune) bool) (string, error) {
 	return r.StringWhile(func(rn rune) bool { return !f(rn) })
 }
+
+// PeekStringUntil acts as StringUntil but does not advance reader position
+func (r *Reader) PeekStringUntil(f func(rn rune) bool) (string, error) {
+	str, err := r.StringUntil(f)
+	if err != nil {
+		return "", err
+	}
+
+	if err := r.UnreadString(str); err != nil {
+		return "", err
+	}
+
+	return str, nil
+}
+
+// Commit clears the internal buffer and therefore removes all data which were already read.
+// After calling Commit any unreads will return ErrNothingToUnread until another read occured.
+func (r *Reader) Commit() {
+	r.buf.Clear()
+}

reader_test.go

@@ -0,0 +1,36 @@
+package bufr
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+)
+
+func TestPos(t *testing.T) {
+	r := NewReader(strings.NewReader("hello world\nsecond line"))
+
+	unread := false
+	for rn, err := r.Rune(); err == nil; rn, err = r.Rune() {
+		index, line, col := r.Pos()
+		fmt.Println(string(rn), index, line, col)
+
+		if !unread && rn == '\n' {
+			for i := 0; i < 5; i++ {
+				r.UnreadRune()
+			}
+			unread = true
+		}
+	}
+}
+
+func TestEOF(t *testing.T) {
+	r := NewReader(strings.NewReader("hello world\nasddsa"))
+
+	for line, err := r.StringUntil(isNewline); err == nil; line, err = r.StringUntil(isNewline) {
+		fmt.Println(line, err)
+	}
+}
+
+func isNewline(rn rune) bool {
+	return rn == '\n'
+}