Push and Pop added
This commit is contained in:
parent
25505b0ea2
commit
af840a5019
@ -6,4 +6,5 @@ import (
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var (
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ErrNothingToUnread = adverr.NewErrTmpl("ErrNothingToUnread", "Unreading failed because there wasn't any Read yet")
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ErrPopFailed = adverr.NewErrTmpl("ErrPopFailed", "stack cannot be popped. It was never pushed")
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)
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3
go.mod
3
go.mod
@ -5,4 +5,7 @@ go 1.19
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require (
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git.milar.in/milarin/adverr v1.1.0
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git.milar.in/milarin/ds v0.0.2
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git.milar.in/milarin/slices v0.0.8
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)
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require git.milar.in/milarin/gmath v0.0.3 // indirect
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8
go.sum
8
go.sum
@ -1,8 +1,8 @@
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git.milar.in/milarin/adverr v1.1.0 h1:jD9WnOvs40lfMhvqQ7cllOaRJNBMWr1f07/s9jAadp0=
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git.milar.in/milarin/adverr v1.1.0/go.mod h1:joU9sBb7ySyNv4SpTXB0Z4o1mjXsArBw4N27wjgzj9E=
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git.milar.in/milarin/ds v0.0.0-20230120204927-7dc44b9cd222 h1:r7gcMqltPqk9U2/+LzEN5dooZ5wiQ8C7SI/nK6T0KjA=
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git.milar.in/milarin/ds v0.0.0-20230120204927-7dc44b9cd222/go.mod h1:HJK7QERcRvV9j7xzEocrKUtW+1q4JB1Ly4Bj54chfwI=
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git.milar.in/milarin/ds v0.0.1 h1:ov4Rp+QiB3xtmV0a4eC+LluxWEOvbykgW+wCchYEp9o=
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git.milar.in/milarin/ds v0.0.1/go.mod h1:HJK7QERcRvV9j7xzEocrKUtW+1q4JB1Ly4Bj54chfwI=
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git.milar.in/milarin/ds v0.0.2 h1:vCA3mDxZUNfvHpzrdz7SeBUKiPn74NTopo915IUG7I0=
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git.milar.in/milarin/ds v0.0.2/go.mod h1:HJK7QERcRvV9j7xzEocrKUtW+1q4JB1Ly4Bj54chfwI=
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git.milar.in/milarin/gmath v0.0.3 h1:ii6rKNItS55O/wtIFhD1cTN2BMwDZjTBmiOocKURvxM=
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git.milar.in/milarin/gmath v0.0.3/go.mod h1:HDLftG5RLpiNGKiIWh+O2G1PYkNzyLDADO8Cd/1abiE=
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git.milar.in/milarin/slices v0.0.8 h1:qN9TE3tkArdTixMKSnwvNPcApwAjxpLVwA5a9k1rm2s=
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git.milar.in/milarin/slices v0.0.8/go.mod h1:qMhdtMnfWswc1rHpwgNw33lB84aNEkdBn5BDiYA+G3k=
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52
reader.go
52
reader.go
@ -6,10 +6,13 @@ import (
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"strings"
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"git.milar.in/milarin/ds"
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"git.milar.in/milarin/slices"
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)
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type Reader struct {
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buf ds.Stack[posRune]
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indices ds.Stack[uint64]
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index uint64
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src *bufio.Reader
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pos *Position
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}
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@ -19,6 +22,8 @@ func New(r io.Reader) *Reader {
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buf: ds.NewArrayStack[posRune](),
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src: bufio.NewReader(r),
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pos: &Position{Index: 0, Line: 1, Column: 1},
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index: 0,
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indices: ds.NewArrayStack[uint64](),
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}
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}
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@ -43,6 +48,7 @@ func (r *Reader) Rune() (rune, error) {
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if err == nil {
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r.buf.Push(r.psrn(rn))
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r.pos.Advance(rn)
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r.index++
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}
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return rn, err
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}
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@ -99,6 +105,8 @@ func (r *Reader) UnreadRune() error {
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r.src = prependRune(rn.Rune, r.src)
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}
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r.index--
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return nil
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}
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@ -250,8 +258,44 @@ func (r *Reader) ExpectOneOfString(str ...string) (string, bool, error) {
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return "", false, nil
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}
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// Commit clears the internal buffer and therefore removes all data which were already read.
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// After calling Commit any unreads will return ErrNothingToUnread until another read occured.
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func (r *Reader) Commit() {
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r.buf.Clear()
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func (r *Reader) Push() {
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r.indices.Push(r.index)
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}
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func (r *Reader) Pop() ([]rune, error) {
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if r.indices.Empty() {
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return nil, ErrPopFailed.New()
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}
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lastIndex := r.indices.Pop()
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currentIndex := r.index
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if lastIndex < currentIndex {
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values := make([]rune, 0, int(currentIndex-lastIndex))
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for i := 0; i < int(currentIndex-lastIndex); i++ {
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err := r.UnreadRune()
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if err != nil {
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return nil, err
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}
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value, err := r.PeekRune()
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if err != nil {
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return nil, err
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}
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values = append(values, value)
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}
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return slices.Reverse(values), nil
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} else if lastIndex > currentIndex {
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values := make([]rune, 0, int(lastIndex-currentIndex))
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for i := 0; i < int(lastIndex-currentIndex); i++ {
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value, err := r.Rune()
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if err != nil {
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return nil, err
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}
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values = append(values, value)
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}
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return values, nil
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}
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return []rune{}, nil
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}
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