Push and Pop added

This commit is contained in:
milarin 2023-08-07 19:51:10 +02:00
parent 25505b0ea2
commit af840a5019
4 changed files with 62 additions and 14 deletions

View File

@ -6,4 +6,5 @@ import (
var ( var (
ErrNothingToUnread = adverr.NewErrTmpl("ErrNothingToUnread", "Unreading failed because there wasn't any Read yet") ErrNothingToUnread = adverr.NewErrTmpl("ErrNothingToUnread", "Unreading failed because there wasn't any Read yet")
ErrPopFailed = adverr.NewErrTmpl("ErrPopFailed", "stack cannot be popped. It was never pushed")
) )

3
go.mod
View File

@ -5,4 +5,7 @@ go 1.19
require ( require (
git.milar.in/milarin/adverr v1.1.0 git.milar.in/milarin/adverr v1.1.0
git.milar.in/milarin/ds v0.0.2 git.milar.in/milarin/ds v0.0.2
git.milar.in/milarin/slices v0.0.8
) )
require git.milar.in/milarin/gmath v0.0.3 // indirect

8
go.sum
View File

@ -1,8 +1,8 @@
git.milar.in/milarin/adverr v1.1.0 h1:jD9WnOvs40lfMhvqQ7cllOaRJNBMWr1f07/s9jAadp0= 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/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 h1:vCA3mDxZUNfvHpzrdz7SeBUKiPn74NTopo915IUG7I0=
git.milar.in/milarin/ds v0.0.2/go.mod h1:HJK7QERcRvV9j7xzEocrKUtW+1q4JB1Ly4Bj54chfwI= git.milar.in/milarin/ds v0.0.2/go.mod h1:HJK7QERcRvV9j7xzEocrKUtW+1q4JB1Ly4Bj54chfwI=
git.milar.in/milarin/gmath v0.0.3 h1:ii6rKNItS55O/wtIFhD1cTN2BMwDZjTBmiOocKURvxM=
git.milar.in/milarin/gmath v0.0.3/go.mod h1:HDLftG5RLpiNGKiIWh+O2G1PYkNzyLDADO8Cd/1abiE=
git.milar.in/milarin/slices v0.0.8 h1:qN9TE3tkArdTixMKSnwvNPcApwAjxpLVwA5a9k1rm2s=
git.milar.in/milarin/slices v0.0.8/go.mod h1:qMhdtMnfWswc1rHpwgNw33lB84aNEkdBn5BDiYA+G3k=

View File

@ -6,10 +6,13 @@ import (
"strings" "strings"
"git.milar.in/milarin/ds" "git.milar.in/milarin/ds"
"git.milar.in/milarin/slices"
) )
type Reader struct { type Reader struct {
buf ds.Stack[posRune] buf ds.Stack[posRune]
indices ds.Stack[uint64]
index uint64
src *bufio.Reader src *bufio.Reader
pos *Position pos *Position
} }
@ -19,6 +22,8 @@ func New(r io.Reader) *Reader {
buf: ds.NewArrayStack[posRune](), buf: ds.NewArrayStack[posRune](),
src: bufio.NewReader(r), src: bufio.NewReader(r),
pos: &Position{Index: 0, Line: 1, Column: 1}, pos: &Position{Index: 0, Line: 1, Column: 1},
index: 0,
indices: ds.NewArrayStack[uint64](),
} }
} }
@ -43,6 +48,7 @@ func (r *Reader) Rune() (rune, error) {
if err == nil { if err == nil {
r.buf.Push(r.psrn(rn)) r.buf.Push(r.psrn(rn))
r.pos.Advance(rn) r.pos.Advance(rn)
r.index++
} }
return rn, err return rn, err
} }
@ -99,6 +105,8 @@ func (r *Reader) UnreadRune() error {
r.src = prependRune(rn.Rune, r.src) r.src = prependRune(rn.Rune, r.src)
} }
r.index--
return nil return nil
} }
@ -250,8 +258,44 @@ func (r *Reader) ExpectOneOfString(str ...string) (string, bool, error) {
return "", false, nil return "", false, nil
} }
// Commit clears the internal buffer and therefore removes all data which were already read. func (r *Reader) Push() {
// After calling Commit any unreads will return ErrNothingToUnread until another read occured. r.indices.Push(r.index)
func (r *Reader) Commit() { }
r.buf.Clear()
func (r *Reader) Pop() ([]rune, error) {
if r.indices.Empty() {
return nil, ErrPopFailed.New()
}
lastIndex := r.indices.Pop()
currentIndex := r.index
if lastIndex < currentIndex {
values := make([]rune, 0, int(currentIndex-lastIndex))
for i := 0; i < int(currentIndex-lastIndex); i++ {
err := r.UnreadRune()
if err != nil {
return nil, err
}
value, err := r.PeekRune()
if err != nil {
return nil, err
}
values = append(values, value)
}
return slices.Reverse(values), nil
} else if lastIndex > currentIndex {
values := make([]rune, 0, int(lastIndex-currentIndex))
for i := 0; i < int(lastIndex-currentIndex); i++ {
value, err := r.Rune()
if err != nil {
return nil, err
}
values = append(values, value)
}
return values, nil
}
return []rune{}, nil
} }