77 lines
1.8 KiB
Go
77 lines
1.8 KiB
Go
package main
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import (
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"io/ioutil"
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"strings"
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)
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// Buffer stores the text for files that are loaded into the text editor
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// It uses a rope to efficiently store the string and contains some
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// simple functions for saving and wrapper functions for modifying the rope
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type Buffer struct {
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// Stores the text of the buffer
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r *Rope
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// Path to the file on disk
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path string
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// Name of the buffer on the status line
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name string
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// This is the text stored everytime the buffer is saved to check if the buffer is modified
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savedText string
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// Provide efficient and easy access to text and lines so the rope toString does not
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// need to be constantly recalculated
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// These variables are updated in the update() function
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text string
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lines []string
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}
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// NewBuffer creates a new buffer from `txt` with path and name `path`
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func NewBuffer(txt, path string) *Buffer {
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b := new(Buffer)
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b.r = newRope(txt)
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b.path = path
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b.name = path
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b.savedText = txt
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b.Update()
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return b
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}
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// Update fetches the string from the rope and updates the `text` and `lines` in the buffer
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func (b *Buffer) Update() {
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b.text = b.r.toString()
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b.lines = strings.Split(b.text, "\n")
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}
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// Save saves the buffer to its default path
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func (b *Buffer) Save() error {
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return b.SaveAs(b.path)
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}
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// SaveAs saves the buffer to a specified path (filename), creating the file if it does not exist
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func (b *Buffer) SaveAs(filename string) error {
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b.savedText = b.text
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err := ioutil.WriteFile(filename, []byte(b.text), 0644)
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return err
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}
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// Insert a string into the rope
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func (b *Buffer) Insert(idx int, value string) {
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b.r.insert(idx, value)
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b.Update()
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}
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// Remove a slice of the rope from start to end (exclusive)
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func (b *Buffer) Remove(start, end int) {
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b.r.remove(start, end)
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b.Update()
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}
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// Len gives the length of the buffer
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func (b *Buffer) Len() int {
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return b.r.len
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}
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