313 lines
8.1 KiB
Go
313 lines
8.1 KiB
Go
package buffer
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import (
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"bufio"
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"io"
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"unicode/utf8"
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"github.com/zyedidia/micro/pkg/highlight"
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)
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// Finds the byte index of the nth rune in a byte slice
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func runeToByteIndex(n int, txt []byte) int {
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if n == 0 {
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return 0
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}
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count := 0
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i := 0
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for len(txt) > 0 {
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_, size := utf8.DecodeRune(txt)
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txt = txt[size:]
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count += size
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i++
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if i == n {
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break
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}
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}
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return count
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}
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// A Line contains the data in bytes as well as a highlight state, match
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// and a flag for whether the highlighting needs to be updated
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type Line struct {
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data []byte
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state highlight.State
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match highlight.LineMatch
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rehighlight bool
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}
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const (
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// Line ending file formats
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FFAuto = 0 // Autodetect format
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FFUnix = 1 // LF line endings (unix style '\n')
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FFDos = 2 // CRLF line endings (dos style '\r\n')
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)
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type FileFormat byte
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// A LineArray simply stores and array of lines and makes it easy to insert
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// and delete in it
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type LineArray struct {
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lines []Line
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Endings FileFormat
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initsize uint64
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}
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// Append efficiently appends lines together
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// It allocates an additional 10000 lines if the original estimate
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// is incorrect
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func Append(slice []Line, data ...Line) []Line {
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l := len(slice)
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if l+len(data) > cap(slice) { // reallocate
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newSlice := make([]Line, (l+len(data))+10000)
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copy(newSlice, slice)
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slice = newSlice
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}
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slice = slice[0 : l+len(data)]
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for i, c := range data {
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slice[l+i] = c
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}
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return slice
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}
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// NewLineArray returns a new line array from an array of bytes
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func NewLineArray(size uint64, endings FileFormat, reader io.Reader) *LineArray {
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la := new(LineArray)
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la.lines = make([]Line, 0, 1000)
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la.initsize = size
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br := bufio.NewReader(reader)
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var loaded int
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n := 0
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for {
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data, err := br.ReadBytes('\n')
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// Detect the line ending by checking to see if there is a '\r' char
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// before the '\n'
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// Even if the file format is set to DOS, the '\r' is removed so
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// that all lines end with '\n'
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dlen := len(data)
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if dlen > 1 && data[dlen-2] == '\r' {
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data = append(data[:dlen-2], '\n')
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if endings == FFAuto {
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la.Endings = FFDos
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}
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dlen = len(data)
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} else if dlen > 0 {
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if endings == FFAuto {
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la.Endings = FFUnix
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}
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}
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// If we are loading a large file (greater than 1000) we use the file
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// size and the length of the first 1000 lines to try to estimate
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// how many lines will need to be allocated for the rest of the file
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// We add an extra 10000 to the original estimate to be safe and give
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// plenty of room for expansion
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if n >= 1000 && loaded >= 0 {
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totalLinesNum := int(float64(size) * (float64(n) / float64(loaded)))
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newSlice := make([]Line, len(la.lines), totalLinesNum+10000)
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copy(newSlice, la.lines)
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la.lines = newSlice
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loaded = -1
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}
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// Counter for the number of bytes in the first 1000 lines
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if loaded >= 0 {
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loaded += dlen
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}
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if err != nil {
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if err == io.EOF {
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la.lines = Append(la.lines, Line{data[:], nil, nil, false})
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}
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// Last line was read
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break
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} else {
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la.lines = Append(la.lines, Line{data[:dlen-1], nil, nil, false})
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}
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n++
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}
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return la
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}
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// Bytes returns the string that should be written to disk when
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// the line array is saved
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func (la *LineArray) Bytes() []byte {
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str := make([]byte, 0, la.initsize+1000) // initsize should provide a good estimate
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for i, l := range la.lines {
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str = append(str, l.data...)
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if i != len(la.lines)-1 {
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if la.Endings == FFDos {
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str = append(str, '\r')
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}
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str = append(str, '\n')
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}
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}
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return str
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}
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// newlineBelow adds a newline below the given line number
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func (la *LineArray) newlineBelow(y int) {
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la.lines = append(la.lines, Line{[]byte{' '}, nil, nil, false})
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copy(la.lines[y+2:], la.lines[y+1:])
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la.lines[y+1] = Line{[]byte{}, la.lines[y].state, nil, false}
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}
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// Inserts a byte array at a given location
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func (la *LineArray) insert(pos Loc, value []byte) {
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x, y := runeToByteIndex(pos.X, la.lines[pos.Y].data), pos.Y
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for i := 0; i < len(value); i++ {
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if value[i] == '\n' {
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la.split(Loc{x, y})
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x = 0
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y++
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continue
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}
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la.insertByte(Loc{x, y}, value[i])
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x++
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}
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}
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// InsertByte inserts a byte at a given location
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func (la *LineArray) insertByte(pos Loc, value byte) {
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la.lines[pos.Y].data = append(la.lines[pos.Y].data, 0)
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copy(la.lines[pos.Y].data[pos.X+1:], la.lines[pos.Y].data[pos.X:])
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la.lines[pos.Y].data[pos.X] = value
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}
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// joinLines joins the two lines a and b
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func (la *LineArray) joinLines(a, b int) {
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la.insert(Loc{len(la.lines[a].data), a}, la.lines[b].data)
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la.deleteLine(b)
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}
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// split splits a line at a given position
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func (la *LineArray) split(pos Loc) {
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la.newlineBelow(pos.Y)
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la.insert(Loc{0, pos.Y + 1}, la.lines[pos.Y].data[pos.X:])
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la.lines[pos.Y+1].state = la.lines[pos.Y].state
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la.lines[pos.Y].state = nil
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la.lines[pos.Y].match = nil
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la.lines[pos.Y+1].match = nil
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la.lines[pos.Y].rehighlight = true
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la.deleteToEnd(Loc{pos.X, pos.Y})
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}
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// removes from start to end
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func (la *LineArray) remove(start, end Loc) []byte {
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sub := la.Substr(start, end)
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startX := runeToByteIndex(start.X, la.lines[start.Y].data)
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endX := runeToByteIndex(end.X, la.lines[end.Y].data)
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if start.Y == end.Y {
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la.lines[start.Y].data = append(la.lines[start.Y].data[:startX], la.lines[start.Y].data[endX:]...)
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} else {
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for i := start.Y + 1; i <= end.Y-1; i++ {
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la.deleteLine(start.Y + 1)
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}
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la.deleteToEnd(Loc{startX, start.Y})
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la.deleteFromStart(Loc{endX - 1, start.Y + 1})
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la.joinLines(start.Y, start.Y+1)
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}
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return sub
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}
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// deleteToEnd deletes from the end of a line to the position
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func (la *LineArray) deleteToEnd(pos Loc) {
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la.lines[pos.Y].data = la.lines[pos.Y].data[:pos.X]
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}
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// deleteFromStart deletes from the start of a line to the position
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func (la *LineArray) deleteFromStart(pos Loc) {
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la.lines[pos.Y].data = la.lines[pos.Y].data[pos.X+1:]
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}
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// deleteLine deletes the line number
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func (la *LineArray) deleteLine(y int) {
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la.lines = la.lines[:y+copy(la.lines[y:], la.lines[y+1:])]
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}
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// DeleteByte deletes the byte at a position
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func (la *LineArray) deleteByte(pos Loc) {
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la.lines[pos.Y].data = la.lines[pos.Y].data[:pos.X+copy(la.lines[pos.Y].data[pos.X:], la.lines[pos.Y].data[pos.X+1:])]
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}
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// Substr returns the string representation between two locations
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func (la *LineArray) Substr(start, end Loc) []byte {
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startX := runeToByteIndex(start.X, la.lines[start.Y].data)
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endX := runeToByteIndex(end.X, la.lines[end.Y].data)
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if start.Y == end.Y {
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src := la.lines[start.Y].data[startX:endX]
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dest := make([]byte, len(src))
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copy(dest, src)
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return dest
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}
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str := make([]byte, 0, len(la.lines[start.Y+1].data)*(end.Y-start.Y))
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str = append(str, la.lines[start.Y].data[startX:]...)
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str = append(str, '\n')
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for i := start.Y + 1; i <= end.Y-1; i++ {
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str = append(str, la.lines[i].data...)
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str = append(str, '\n')
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}
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str = append(str, la.lines[end.Y].data[:endX]...)
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return str
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}
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// LinesNum returns the number of lines in the buffer
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func (la *LineArray) LinesNum() int {
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return len(la.lines)
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}
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// Start returns the start of the buffer
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func (la *LineArray) Start() Loc {
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return Loc{0, 0}
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}
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// End returns the location of the last character in the buffer
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func (la *LineArray) End() Loc {
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numlines := len(la.lines)
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return Loc{utf8.RuneCount(la.lines[numlines-1].data), numlines - 1}
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}
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// LineBytes returns line n as an array of bytes
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func (la *LineArray) LineBytes(n int) []byte {
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if n >= len(la.lines) || n < 0 {
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return []byte{}
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}
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return la.lines[n].data
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}
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// State gets the highlight state for the given line number
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func (la *LineArray) State(lineN int) highlight.State {
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return la.lines[lineN].state
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}
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// SetState sets the highlight state at the given line number
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func (la *LineArray) SetState(lineN int, s highlight.State) {
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la.lines[lineN].state = s
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}
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// SetMatch sets the match at the given line number
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func (la *LineArray) SetMatch(lineN int, m highlight.LineMatch) {
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la.lines[lineN].match = m
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}
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// Match retrieves the match for the given line number
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func (la *LineArray) Match(lineN int) highlight.LineMatch {
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return la.lines[lineN].match
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}
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func (la *LineArray) Rehighlight(lineN int) bool {
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return la.lines[lineN].rehighlight
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}
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func (la *LineArray) SetRehighlight(lineN int, on bool) {
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la.lines[lineN].rehighlight = on
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}
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