buffer

Documentation

Index

• func SetDebug(enable bool)
• type CursorPos
• type PieceTable
  • func NewPieceTable(text []byte) *PieceTable
  • func NewTextSource() *PieceTable
  • func (pt *PieceTable) Changed() bool
  • func (pt *PieceTable) GroupOp()
  • func (pt *PieceTable) Len() int
  • func (pt *PieceTable) Lines() int
  • func (pt *PieceTable) ReadAt(p []byte, offset int64) (total int, err error)
  • func (pt *PieceTable) ReadRuneAt(runeOff int) (rune, error)
  • func (pt *PieceTable) Redo() ([]CursorPos, bool)
  • func (pt *PieceTable) Replace(startOff, endOff int, text string) bool
  • func (pt *PieceTable) RuneOffset(runeOff int) int
  • func (pt *PieceTable) SetText(text []byte)
  • func (pt *PieceTable) Size() int
  • func (pt *PieceTable) UnGroupOp()
  • func (pt *PieceTable) Undo() ([]CursorPos, bool)
• type TextReader
  • func NewReader(src TextSource) TextReader
• type TextSource

Functions

func SetDebug

func SetDebug(enable bool)

Set debug mode or not. In debug mode, the internal states of PieceTable is printed to console.

Types

type CursorPos

type CursorPos struct {
	// start rune offset
	Start int
	// end rune offset
	End int
}

CursorPos keep track of the previous cursor position of undo/redo.

type PieceTable

type PieceTable struct {
	// contains filtered or unexported fields
}

PieceTable implements a piece table data structure. See the following resources for more information:

https://en.wikipedia.org/wiki/Piece_table

https://www.cs.unm.edu/~crowley/papers/sds.pdf

This implementation is heavily inspired by the design described in James Brown's Piece Chain(http://www.catch22.net/tuts/neatpad/piece-chains).

func NewPieceTable

func NewPieceTable(text []byte) *PieceTable

func NewTextSource

func NewTextSource() *PieceTable

func (*PieceTable) Changed

func (pt *PieceTable) Changed() bool

func (*PieceTable) GroupOp

func (pt *PieceTable) GroupOp()

Group operations such as insert, earase or replace in a batch. Nested call share the same single batch.

func (*PieceTable) Len

func (pt *PieceTable) Len() int

Size returns the total length of the document data in runes.

func (*PieceTable) Lines

func (pt *PieceTable) Lines() int

func (*PieceTable) ReadAt

func (pt *PieceTable) ReadAt(p []byte, offset int64) (total int, err error)

ReadAt implements io.ReaderAt

func (*PieceTable) ReadRuneAt

func (pt *PieceTable) ReadRuneAt(runeOff int) (rune, error)

func (*PieceTable) Redo

func (pt *PieceTable) Redo() ([]CursorPos, bool)

func (*PieceTable) Replace

func (pt *PieceTable) Replace(startOff, endOff int, text string) bool

Replace removes text from startOff to endOff(exclusive), and insert text at the position of startOff.

func (*PieceTable) RuneOffset

func (pt *PieceTable) RuneOffset(runeOff int) int

RuneOffset returns the byte offset for the rune at position runeOff.

func (*PieceTable) SetText

func (pt *PieceTable) SetText(text []byte)

func (*PieceTable) Size

func (pt *PieceTable) Size() int

func (*PieceTable) UnGroupOp

func (pt *PieceTable) UnGroupOp()

Ungroup a batch. Latter insert, earase or replace operations outside of a group is not batched.

This results in global batch op if writes are accessed from concurrent goroutine, may be not what the user want. But in our scenarios most of the time it is safe to do so.

func (*PieceTable) Undo

func (pt *PieceTable) Undo() ([]CursorPos, bool)

type TextReader

type TextReader interface {
	io.Seeker
	io.Reader
	//ReadAll returns the contents of the editor.
	ReadAll(buf []byte) []byte
}

func NewReader

func NewReader(src TextSource) TextReader

type TextSource

type TextSource interface {
	io.ReaderAt

	// ReadRuneAt reads the rune starting at the given rune offset, if any.
	ReadRuneAt(runeOff int) (rune, error)

	// RuneOffset returns the byte offset for the rune at position runeIndex.
	RuneOffset(runeIndex int) int

	// Lines returns the total number of lines/paragraphs of the source.
	Lines() int

	// Len is the length of the editor contents, in runes.
	Len() int

	// Size returns the size of the editor content in bytes.
	Size() int

	// SetText reset the buffer and replace the content of the buffer with the provided text.
	SetText(text []byte)

	// Replace replace text from startOff to endOff(exclusive) with text.
	Replace(startOff, endOff int, text string) bool

	// Undo the last insert, erase, or replace, or a group of operations.
	// It returns all the cursor positions after undo.
	Undo() ([]CursorPos, bool)
	// Redo the last insert, erase, or replace, or a group of operations.
	// It returns all the cursor positions after undo.
	Redo() ([]CursorPos, bool)

	// Group operations such as insert, earase or replace in a batch.
	// Nested call share the same single batch.
	GroupOp()

	// Ungroup a batch. Latter insert, earase or replace operations outside of
	// a group is not batched.
	UnGroupOp()

	// Changed report whether the contents have changed since the last call to Changed.
	Changed() bool
}

TextSource provides data for editor.

Basic editing operations, such as insert, delete, replace, undo/redo are supported. If used with GroupOp and UnGroupOp, the undo and redo operations can be batched.