5 "github.com/vinzmay/go-rope"
10 // Buffer stores the text for files that are loaded into the text editor
11 // It uses a rope to efficiently store the string and contains some
12 // simple functions for saving and wrapper functions for modifying the rope
14 // Stores the text of the buffer
17 // Path to the file on disk
19 // Name of the buffer on the status line
22 // This is the text stored every time the buffer is saved to check if the buffer is modified
25 dirtySinceLastCheck bool
27 // Provide efficient and easy access to text and lines so the rope String does not
28 // need to be constantly recalculated
29 // These variables are updated in the update() function
33 // Syntax highlighting rules
35 // The buffer's filetype
39 // NewBuffer creates a new buffer from `txt` with path and name `path`
40 func NewBuffer(txt, path string) *Buffer {
49 b.savedText = md5.Sum([]byte(txt))
57 // UpdateRules updates the syntax rules and filetype for this buffer
58 // This is called when the colorscheme changes
59 func (b *Buffer) UpdateRules() {
60 b.rules, b.Filetype = GetRules(b)
63 func (b *Buffer) String() string {
71 // Update fetches the string from the rope and updates the `text` and `lines` in the buffer
72 func (b *Buffer) Update() {
73 b.Lines = strings.Split(b.String(), "\n")
74 b.NumLines = len(b.Lines)
77 // Save saves the buffer to its default path
78 func (b *Buffer) Save() error {
79 return b.SaveAs(b.Path)
82 // SaveAs saves the buffer to a specified path (filename), creating the file if it does not exist
83 func (b *Buffer) SaveAs(filename string) error {
85 data := []byte(b.String())
86 err := ioutil.WriteFile(filename, data, 0644)
88 b.savedText = md5.Sum(data)
94 // IsDirty returns whether or not the buffer has been modified compared to the one on disk
95 func (b *Buffer) IsDirty() bool {
96 if !b.dirtySinceLastCheck {
99 if b.netInsertions == 0 {
100 isDirty := b.savedText != md5.Sum([]byte(b.String()))
101 b.dirtySinceLastCheck = isDirty
107 // Insert a string into the rope
108 func (b *Buffer) Insert(idx int, value string) {
109 b.dirtySinceLastCheck = true
110 b.netInsertions += len(value)
111 b.r = b.r.Insert(idx, value)
115 // Remove a slice of the rope from start to end (exclusive)
116 // Returns the string that was removed
117 func (b *Buffer) Remove(start, end int) string {
118 b.dirtySinceLastCheck = true
119 b.netInsertions -= end - start
126 removed := b.r.Report(start+1, end-start)
127 // The rope implenentation I am using wants indicies starting at 1 instead of 0
130 b.r = b.r.Delete(start, end-start)
135 // Len gives the length of the buffer
136 func (b *Buffer) Len() int {