85 lines
1.4 KiB
Go
85 lines
1.4 KiB
Go
package editor
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import (
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"strings"
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)
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type row struct {
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chars []rune
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render []rune
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}
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func newRow(s string) *row {
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var chars []rune
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var render []rune
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for _, ch := range s {
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chars = append(chars, ch)
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render = append(render, ch)
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}
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return &row{chars, render}
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}
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func (r *row) size() int {
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return len(r.chars)
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}
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func (r *row) rSize() int {
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return len(r.render)
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}
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func (r *row) insertRune(ch rune, at int) {
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// If insertion index is invalid, just
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// append the rune to the end of the array
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if at < 0 || at >= r.size() {
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r.chars = append(r.chars, ch)
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r.update()
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return
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}
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var newSlice []rune
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// Split the character array at the insertion point
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start := r.chars[0:at]
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end := r.chars[at:r.size()]
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// Splice it back together
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newSlice = append(newSlice, start...)
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newSlice = append(newSlice, ch)
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newSlice = append(newSlice, end...)
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r.chars = newSlice
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r.update()
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}
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func (r *row) update() {
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r.render = r.render[:0]
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replacement := strings.Repeat(" ", KiloTabStop)
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str := strings.ReplaceAll(string(r.chars), "\t", replacement)
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for _, ch := range str {
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r.render = append(r.render, ch)
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}
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}
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func (r *row) toString() string {
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return string(r.chars)
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}
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func (r *row) cursorXToRenderX(cursorX int) int {
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renderX := 0
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i := 0
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for ; i < cursorX; i++ {
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if r.chars[i] == '\t' {
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renderX += (KiloTabStop - 1) - (renderX % KiloTabStop)
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}
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renderX += 1
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}
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return renderX
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}
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