From d60096e5b23deb3ca5eb601a2c7343b7b022ea18 Mon Sep 17 00:00:00 2001
From: milarin <milaring@proton.me>
Date: Fri, 20 Jan 2023 22:16:46 +0100
Subject: [PATCH] Commit() method implemented

---
 errors.go |  2 +-
 go.mod    |  8 ++++----
 go.sum    | 12 ++++++++----
 reader.go | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++---
 4 files changed, 65 insertions(+), 12 deletions(-)

diff --git a/errors.go b/errors.go
index 72bfa8d..7152e3a 100644
--- a/errors.go
+++ b/errors.go
@@ -1,7 +1,7 @@
 package bufr
 
 import (
-	"git.tordarus.net/Tordarus/adverr"
+	"git.milar.in/milarin/adverr"
 )
 
 var (
diff --git a/go.mod b/go.mod
index ec51b77..b1bfac8 100644
--- a/go.mod
+++ b/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
 )
diff --git a/go.sum b/go.sum
index 3173da5..010c479 100644
--- a/go.sum
+++ b/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=
diff --git a/reader.go b/reader.go
index 9d4172f..a0e9e57 100644
--- a/reader.go
+++ b/reader.go
@@ -5,18 +5,18 @@ import (
 	"io"
 	"strings"
 
-	"git.tordarus.net/Tordarus/dstruct"
+	"git.milar.in/milarin/ds"
 )
 
 type Reader struct {
-	buf *dstruct.Stack[posRune]
+	buf ds.Stack[posRune]
 	src *bufio.Reader
 	pos *Position
 }
 
 func NewReader(r io.Reader) *Reader {
 	return &Reader{
-		buf: new(dstruct.Stack[posRune]),
+		buf: ds.NewArrayStack[posRune](),
 		src: bufio.NewReader(r),
 		pos: &Position{},
 	}
@@ -43,6 +43,21 @@ func (r *Reader) Rune() (rune, error) {
 	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
+}
+
 // UnreadRune unreads the last rune.
 // The next read will include the unread rune.
 // It returns ErrNothingToUnread if there wasn't any read yet
@@ -93,7 +108,41 @@ func (r *Reader) StringWhile(f func(rn rune) bool) (string, error) {
 	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()
+}