import (
"regexp"
"strings"
+
+ "github.com/dlclark/regexp2"
)
func combineLineMatch(src, dst LineMatch) LineMatch {
return dst
}
+// A State represents the region at the end of a line
type State *Region
+// LineStates is an interface for a buffer-like object which can also store the states and matches for every line
type LineStates interface {
- LineData() [][]byte
+ Line(n int) string
+ LinesNum() int
State(lineN int) State
SetState(lineN int, s State)
SetMatch(lineN int, m LineMatch)
}
+// A Highlighter contains the information needed to highlight a string
type Highlighter struct {
lastRegion *Region
def *Def
}
+// NewHighlighter returns a new highlighter from the given syntax definition
func NewHighlighter(def *Def) *Highlighter {
h := new(Highlighter)
h.def = def
return h
}
+// LineMatch represents the syntax highlighting matches for one line. Each index where the coloring is changed is marked with that
+// color's group (represented as one byte)
type LineMatch map[int]uint8
-func FindIndex(regex *regexp.Regexp, str []byte, canMatchStart, canMatchEnd bool) []int {
+func findIndex(regex *regexp2.Regexp, str []byte, canMatchStart, canMatchEnd bool) []int {
regexStr := regex.String()
if strings.Contains(regexStr, "^") {
if !canMatchStart {
return nil
}
}
- return regex.FindIndex(str)
+ match, _ := regex.FindStringMatch(string(str))
+ if match == nil {
+ return nil
+ }
+ return []int{match.Index, match.Index + match.Length}
}
-func FindAllIndex(regex *regexp.Regexp, str []byte, canMatchStart, canMatchEnd bool) [][]int {
+func findAllIndex(regex *regexp.Regexp, str []byte, canMatchStart, canMatchEnd bool) [][]int {
regexStr := regex.String()
if strings.Contains(regexStr, "^") {
if !canMatchStart {
return regex.FindAllIndex(str, -1)
}
-func (h *Highlighter) highlightRegion(start int, canMatchEnd bool, lineNum int, line []byte, region *Region) LineMatch {
- highlights := make(LineMatch)
+func (h *Highlighter) highlightRegion(highlights LineMatch, start int, canMatchEnd bool, lineNum int, line []byte, region *Region, statesOnly bool) LineMatch {
+ // highlights := make(LineMatch)
if start == 0 {
- highlights[0] = region.group
+ if !statesOnly {
+ highlights[0] = region.group
+ }
}
- loc := FindIndex(region.end, line, start == 0, canMatchEnd)
+ loc := findIndex(region.end, line, start == 0, canMatchEnd)
if loc != nil {
+ if !statesOnly {
+ highlights[start+loc[1]-1] = region.group
+ }
if region.parent == nil {
- highlights[start+loc[1]] = 0
- return combineLineMatch(highlights,
- combineLineMatch(h.highlightRegion(start, false, lineNum, line[:loc[0]], region),
- h.highlightEmptyRegion(start+loc[1], canMatchEnd, lineNum, line[loc[1]:])))
+ if !statesOnly {
+ highlights[start+loc[1]] = 0
+ }
+ h.highlightRegion(highlights, start, false, lineNum, line[:loc[0]], region, statesOnly)
+ h.highlightEmptyRegion(highlights, start+loc[1], canMatchEnd, lineNum, line[loc[1]:], statesOnly)
+ return highlights
+ }
+ if !statesOnly {
+ highlights[start+loc[1]] = region.parent.group
}
- highlights[start+loc[1]] = region.parent.group
- return combineLineMatch(highlights,
- combineLineMatch(h.highlightRegion(start, false, lineNum, line[:loc[0]], region),
- h.highlightRegion(start+loc[1], canMatchEnd, lineNum, line[loc[1]:], region.parent)))
+ h.highlightRegion(highlights, start, false, lineNum, line[:loc[0]], region, statesOnly)
+ h.highlightRegion(highlights, start+loc[1], canMatchEnd, lineNum, line[loc[1]:], region.parent, statesOnly)
+ return highlights
}
- if len(line) == 0 {
+ if len(line) == 0 || statesOnly {
if canMatchEnd {
h.lastRegion = region
}
firstLoc := []int{len(line), 0}
var firstRegion *Region
for _, r := range region.rules.regions {
- loc := FindIndex(r.start, line, start == 0, canMatchEnd)
+ loc := findIndex(r.start, line, start == 0, canMatchEnd)
if loc != nil {
if loc[0] < firstLoc[0] {
firstLoc = loc
}
if firstLoc[0] != len(line) {
highlights[start+firstLoc[0]] = firstRegion.group
- return combineLineMatch(highlights,
- combineLineMatch(h.highlightRegion(start, false, lineNum, line[:firstLoc[0]], region),
- h.highlightRegion(start+firstLoc[1], canMatchEnd, lineNum, line[firstLoc[1]:], firstRegion)))
+ h.highlightRegion(highlights, start, false, lineNum, line[:firstLoc[0]], region, statesOnly)
+ h.highlightRegion(highlights, start+firstLoc[1], canMatchEnd, lineNum, line[firstLoc[1]:], firstRegion, statesOnly)
+ return highlights
+ }
+
+ fullHighlights := make([]uint8, len([]rune(string(line))))
+ for i := 0; i < len(fullHighlights); i++ {
+ fullHighlights[i] = region.group
}
for _, p := range region.rules.patterns {
- matches := FindAllIndex(p.regex, line, start == 0, canMatchEnd)
+ matches := findAllIndex(p.regex, line, start == 0, canMatchEnd)
for _, m := range matches {
- highlights[start+m[0]] = p.group
- if _, ok := highlights[start+m[1]]; !ok {
- highlights[start+m[1]] = region.group
+ for i := m[0]; i < m[1]; i++ {
+ fullHighlights[i] = p.group
+ }
+ }
+ }
+ for i, h := range fullHighlights {
+ if i == 0 || h != fullHighlights[i-1] {
+ if _, ok := highlights[start+i]; !ok {
+ highlights[start+i] = h
}
}
}
return highlights
}
-func (h *Highlighter) highlightEmptyRegion(start int, canMatchEnd bool, lineNum int, line []byte) LineMatch {
- highlights := make(LineMatch)
+func (h *Highlighter) highlightEmptyRegion(highlights LineMatch, start int, canMatchEnd bool, lineNum int, line []byte, statesOnly bool) LineMatch {
if len(line) == 0 {
if canMatchEnd {
h.lastRegion = nil
firstLoc := []int{len(line), 0}
var firstRegion *Region
for _, r := range h.def.rules.regions {
- loc := FindIndex(r.start, line, start == 0, canMatchEnd)
+ loc := findIndex(r.start, line, start == 0, canMatchEnd)
if loc != nil {
if loc[0] < firstLoc[0] {
firstLoc = loc
}
}
if firstLoc[0] != len(line) {
- highlights[start+firstLoc[0]] = firstRegion.group
- return combineLineMatch(highlights,
- combineLineMatch(h.highlightEmptyRegion(start, false, lineNum, line[:firstLoc[0]]),
- h.highlightRegion(start+firstLoc[1], canMatchEnd, lineNum, line[firstLoc[1]:], firstRegion)))
+ if !statesOnly {
+ highlights[start+firstLoc[0]] = firstRegion.group
+ }
+ h.highlightEmptyRegion(highlights, start, false, lineNum, line[:firstLoc[0]], statesOnly)
+ h.highlightRegion(highlights, start+firstLoc[1], canMatchEnd, lineNum, line[firstLoc[1]:], firstRegion, statesOnly)
+ return highlights
}
+ if statesOnly {
+ if canMatchEnd {
+ h.lastRegion = nil
+ }
+
+ return highlights
+ }
+
+ fullHighlights := make([]uint8, len(line))
for _, p := range h.def.rules.patterns {
- matches := FindAllIndex(p.regex, line, start == 0, canMatchEnd)
+ matches := findAllIndex(p.regex, line, start == 0, canMatchEnd)
for _, m := range matches {
- highlights[start+m[0]] = p.group
- if _, ok := highlights[start+m[1]]; !ok {
- highlights[start+m[1]] = 0
+ for i := m[0]; i < m[1]; i++ {
+ fullHighlights[i] = p.group
+ }
+ }
+ }
+ for i, h := range fullHighlights {
+ if i == 0 || h != fullHighlights[i-1] {
+ if _, ok := highlights[start+i]; !ok {
+ highlights[start+i] = h
}
}
}
return highlights
}
+// HighlightString syntax highlights a string
+// Use this function for simple syntax highlighting and use the other functions for
+// more advanced syntax highlighting. They are optimized for quick rehighlighting of the same
+// text with minor changes made
func (h *Highlighter) HighlightString(input string) []LineMatch {
lines := strings.Split(input, "\n")
var lineMatches []LineMatch
for i := 0; i < len(lines); i++ {
line := []byte(lines[i])
+ highlights := make(LineMatch)
if i == 0 || h.lastRegion == nil {
- lineMatches = append(lineMatches, h.highlightEmptyRegion(0, true, i, line))
+ lineMatches = append(lineMatches, h.highlightEmptyRegion(highlights, 0, true, i, line, false))
} else {
- lineMatches = append(lineMatches, h.highlightRegion(0, true, i, line, h.lastRegion))
+ lineMatches = append(lineMatches, h.highlightRegion(highlights, 0, true, i, line, h.lastRegion, false))
}
}
return lineMatches
}
-func (h *Highlighter) Highlight(input LineStates, startline int) {
- lines := input.LineData()
+// HighlightStates correctly sets all states for the buffer
+func (h *Highlighter) HighlightStates(input LineStates) {
+ for i := 0; i < input.LinesNum(); i++ {
+ line := []byte(input.Line(i))
+ // highlights := make(LineMatch)
- for i := startline; i < len(lines); i++ {
- line := []byte(lines[i])
-
- var match LineMatch
if i == 0 || h.lastRegion == nil {
- match = h.highlightEmptyRegion(0, true, i, line)
+ h.highlightEmptyRegion(nil, 0, true, i, line, true)
} else {
- match = h.highlightRegion(0, true, i, line, h.lastRegion)
+ h.highlightRegion(nil, 0, true, i, line, h.lastRegion, true)
}
curState := h.lastRegion
- input.SetMatch(i, match)
input.SetState(i, curState)
}
}
-func (h *Highlighter) ReHighlightLine(input LineStates, lineN int) {
- lines := input.LineData()
+// HighlightMatches sets the matches for each line in between startline and endline
+// It sets all other matches in the buffer to nil to conserve memory
+// This assumes that all the states are set correctly
+func (h *Highlighter) HighlightMatches(input LineStates, startline, endline int) {
+ for i := startline; i < endline; i++ {
+ if i >= input.LinesNum() {
+ break
+ }
- line := []byte(lines[lineN])
+ line := []byte(input.Line(i))
+ highlights := make(LineMatch)
- h.lastRegion = nil
- if lineN > 0 {
- h.lastRegion = input.State(lineN - 1)
- }
+ var match LineMatch
+ if i == 0 || input.State(i-1) == nil {
+ match = h.highlightEmptyRegion(highlights, 0, true, i, line, false)
+ } else {
+ match = h.highlightRegion(highlights, 0, true, i, line, input.State(i-1), false)
+ }
- var match LineMatch
- if lineN == 0 || h.lastRegion == nil {
- match = h.highlightEmptyRegion(0, true, lineN, line)
- } else {
- match = h.highlightRegion(0, true, lineN, line, h.lastRegion)
+ input.SetMatch(i, match)
}
- curState := h.lastRegion
-
- input.SetMatch(lineN, match)
- input.SetState(lineN, curState)
}
-func (h *Highlighter) ReHighlight(input LineStates, startline int) {
- lines := input.LineData()
+// ReHighlightStates will scan down from `startline` and set the appropriate end of line state
+// for each line until it comes across the same state in two consecutive lines
+func (h *Highlighter) ReHighlightStates(input LineStates, startline int) {
+ // lines := input.LineData()
h.lastRegion = nil
if startline > 0 {
h.lastRegion = input.State(startline - 1)
}
- for i := startline; i < len(lines); i++ {
- line := []byte(lines[i])
+ for i := startline; i < input.LinesNum(); i++ {
+ line := []byte(input.Line(i))
+ // highlights := make(LineMatch)
- var match LineMatch
+ // var match LineMatch
if i == 0 || h.lastRegion == nil {
- match = h.highlightEmptyRegion(0, true, i, line)
+ h.highlightEmptyRegion(nil, 0, true, i, line, true)
} else {
- match = h.highlightRegion(0, true, i, line, h.lastRegion)
+ h.highlightRegion(nil, 0, true, i, line, h.lastRegion, true)
}
curState := h.lastRegion
lastState := input.State(i)
- input.SetMatch(i, match)
input.SetState(i, curState)
if curState == lastState {
}
}
}
+
+// ReHighlightLine will rehighlight the state and match for a single line
+func (h *Highlighter) ReHighlightLine(input LineStates, lineN int) {
+ line := []byte(input.Line(lineN))
+ highlights := make(LineMatch)
+
+ h.lastRegion = nil
+ if lineN > 0 {
+ h.lastRegion = input.State(lineN - 1)
+ }
+
+ var match LineMatch
+ if lineN == 0 || h.lastRegion == nil {
+ match = h.highlightEmptyRegion(highlights, 0, true, lineN, line, false)
+ } else {
+ match = h.highlightRegion(highlights, 0, true, lineN, line, h.lastRegion, false)
+ }
+ curState := h.lastRegion
+
+ input.SetMatch(lineN, match)
+ input.SetState(lineN, curState)
+}