diff options
Diffstat (limited to 'lib/diskio')
-rw-r--r-- | lib/diskio/seq.go | 63 |
1 files changed, 19 insertions, 44 deletions
diff --git a/lib/diskio/seq.go b/lib/diskio/seq.go index 3c5f4ae..f8e6ea8 100644 --- a/lib/diskio/seq.go +++ b/lib/diskio/seq.go @@ -1,68 +1,43 @@ -// Copyright (C) 2022 Luke Shumaker <lukeshu@lukeshu.com> +// Copyright (C) 2022-2023 Luke Shumaker <lukeshu@lukeshu.com> // // SPDX-License-Identifier: GPL-2.0-or-later package diskio -import ( - "fmt" - "io" -) - // interface ///////////////////////////////////////////////////////// -type Sequence[K ~int64, V any] interface { +type Sequence[K ~int64 | ~int, V any] interface { + SeqLen() K // Get the value at 'pos' in the sequence. Positions start at - // 0 and increment naturally. Return an error that is io.EOF - // if 'pos' is past the end of the sequence'. - Get(pos K) (V, error) + // 0 and increment naturally. It is invalid to call + // SeqGet(pos) with a pos that is >= SeqLen(). + SeqGet(pos K) V } // implementation: slice ///////////////////////////////////////////// -type SliceSequence[K ~int64, V any] []V +type SliceSequence[K ~int64 | ~int, V any] []V + +var _ Sequence[assertAddr, byte] = SliceSequence[assertAddr, byte](nil) -var _ Sequence[assertAddr, byte] = SliceSequence[assertAddr, byte]([]byte(nil)) +func (s SliceSequence[K, V]) SeqLen() K { + return K(len(s)) +} -func (s SliceSequence[K, V]) Get(i K) (V, error) { - if i >= K(len(s)) { - var v V - return v, io.EOF - } - return s[int(i)], nil +func (s SliceSequence[K, V]) SeqGet(i K) V { + return s[int(i)] } // implementation: string //////////////////////////////////////////// -type StringSequence[K ~int64] string +type StringSequence[K ~int64 | ~int] string var _ Sequence[assertAddr, byte] = StringSequence[assertAddr]("") -func (s StringSequence[K]) Get(i K) (byte, error) { - if i >= K(len(s)) { - return 0, io.EOF - } - return s[int(i)], nil +func (s StringSequence[K]) SeqLen() K { + return K(len(s)) } -// implementation: io.ByteReader ///////////////////////////////////// - -type ByteReaderSequence[K ~int64] struct { - R io.ByteReader - pos K -} - -var _ Sequence[assertAddr, byte] = &ByteReaderSequence[assertAddr]{R: nil} - -func (s *ByteReaderSequence[K]) Get(i K) (byte, error) { - if i != s.pos { - return 0, fmt.Errorf("%T.Get(%v): can only call .Get(%v)", - s, i, s.pos) - } - chr, err := s.R.ReadByte() - if err != nil { - return chr, err - } - s.pos++ - return chr, nil +func (s StringSequence[K]) SeqGet(i K) byte { + return s[int(i)] } |