Extracting brace matching logic into its own public function

internal/buffer/buffer.go

@@ -1141,7 +1141,8 @@ var BracePairs = [][2]rune{
 	{'[', ']'},
 }
 
-func (b *Buffer) getSortedSyntaxIndices(lineN int) []int {
+// Returns the indices of syntax groups in ascending order
+func (b *Buffer) GetSortedSyntaxGroupIndices(lineN int) []int {
 	keys := make([]int, 0, len(b.Match(lineN)))
 	for k := range b.Match(lineN) {
 		keys = append(keys, k)
@@ -1151,9 +1152,13 @@ func (b *Buffer) getSortedSyntaxIndices(lineN int) []int {
 }
 
 // Returns the Group (syntax highlight group ID) at the specified location and a boolean
-// that indicates if a group is found or not
-func (b *Buffer) GetGroupAtLoc(loc Loc) (highlight.Group, bool) {
-	sortedIndices := b.getSortedSyntaxIndices(loc.Y)
+// that indicates if a group is found or not.
+// This optionally accepts sorted Group indices returned from GetSortedSyntaxGroupIndices()
+// which can be reused on the same line.
+func (b *Buffer) GetGroupAtLoc(loc Loc, sortedIndices []int) (highlight.Group, bool) {
+ 	if sortedIndices == nil {
+		sortedIndices = b.GetSortedSyntaxGroupIndices(loc.Y)
+ 	}
 	i := sort.SearchInts(sortedIndices, loc.X)
 	if i == 0 || i == len(sortedIndices) {
 		return 0, false
@@ -1164,57 +1169,108 @@ func (b *Buffer) GetGroupAtLoc(loc Loc) (highlight.Group, bool) {
 	return b.Match(loc.Y)[sortedIndices[i - 1]], true
 }
 
-func (b *Buffer) isLocInStringOrComment(loc Loc) bool {
-	g, gFound := b.GetGroupAtLoc(loc)
+func (b *Buffer) isLocInStringOrComment(loc Loc, sortedIndices []int) bool {
+	g, gFound := b.GetGroupAtLoc(loc, sortedIndices)
 	if gFound && (g.String() == "constant.string" || strings.Contains(g.String(), "comment")) {
 		return true
 	}
 	return false
 }
 
+func (b *Buffer) FindOpeningBrace(braceType [2]rune, start Loc) (Loc, bool) {
+	startChar := []rune(string(b.LineBytes(start.Y)))[start.X]
+	var i int
+	if startChar == braceType[1] {
+		i = 0
+	} else {
+		i = 1
+	}
+	for y := start.Y; y >= 0; y-- {
+		var sortedGroups []int
+		sortedGroupsPopulated := false
+		l := []rune(string(b.lines[y].data))
+		xInit := len(l) - 1
+		if y == start.Y {
+			xInit = start.X
+		}
+		for x := xInit; x >= 0; x-- {
+			r := l[x]
+			if r == braceType[1] {
+				if !sortedGroupsPopulated {
+					sortedGroups = b.GetSortedSyntaxGroupIndices(y)
+					sortedGroupsPopulated = true
+				}
+			 	if !b.isLocInStringOrComment(Loc{x, y}, sortedGroups) {
+					i++
+				}
+			} else if r == braceType[0]{
+				if !sortedGroupsPopulated {
+					sortedGroups = b.GetSortedSyntaxGroupIndices(y)
+					sortedGroupsPopulated = true
+				}
+				if !b.isLocInStringOrComment(Loc{x, y}, sortedGroups) {
+					i--
+				}
+				if i == 0 {
+					return Loc{x, y}, true
+				}
+			}
+		}
+	}
+	return start, false
+}
+
+func (b *Buffer) FindClosingBrace(braceType [2]rune, start Loc) (Loc, bool) {
+	startChar := []rune(string(b.LineBytes(start.Y)))[start.X]
+	var i int
+	if startChar == braceType[0] {
+		i = 0
+	} else {
+		i = 1
+	}
+	for y := start.Y; y < b.LinesNum(); y++ {
+		var sortedGroups []int
+		sortedGroupsPopulated := false
+		l := []rune(string(b.LineBytes(y)))
+		xInit := 0
+		if y == start.Y {
+			xInit = start.X
+		}
+		for x := xInit; x < len(l); x++ {
+			r := l[x]
+			if r == braceType[0] {
+				if !sortedGroupsPopulated {
+					sortedGroups = b.GetSortedSyntaxGroupIndices(y)
+					sortedGroupsPopulated = true
+				}
+				if !b.isLocInStringOrComment(Loc{x, y}, sortedGroups) {
+					i++
+				}
+			} else if r == braceType[1] {
+				if !sortedGroupsPopulated {
+					sortedGroups = b.GetSortedSyntaxGroupIndices(y)
+					sortedGroupsPopulated = true
+				}
+				if !b.isLocInStringOrComment(Loc{x, y}, sortedGroups) {
+					i--
+				}
+				if i == 0 {
+					return Loc{x, y}, true
+				}
+			}
+		}
+	}
+	return start, false
+}
+
 func (b *Buffer) findMatchingBrace(braceType [2]rune, start Loc, char rune) (Loc, bool) {
-	if b.isLocInStringOrComment(start) {
+	if b.isLocInStringOrComment(start, nil) {
 		return start, false
 	}
-	var i int
 	if char == braceType[0] {
-		for y := start.Y; y < b.LinesNum(); y++ {
-			l := []rune(string(b.LineBytes(y)))
-			xInit := 0
-			if y == start.Y {
-				xInit = start.X
-			}
-			for x := xInit; x < len(l); x++ {
-				r := l[x]
-				if r == braceType[0] && !b.isLocInStringOrComment(Loc{x, y}) {
-					i++
-				} else if r == braceType[1] && !b.isLocInStringOrComment(Loc{x, y}) {
-					i--
-					if i == 0 {
-						return Loc{x, y}, true
-					}
-				}
-			}
-		}
+		return b.FindClosingBrace(braceType, start)
 	} else if char == braceType[1] {
-		for y := start.Y; y >= 0; y-- {
-			l := []rune(string(b.lines[y].data))
-			xInit := len(l) - 1
-			if y == start.Y {
-				xInit = start.X
-			}
-			for x := xInit; x >= 0; x-- {
-				r := l[x]
-				if r == braceType[1] && !b.isLocInStringOrComment(Loc{x, y}){
-					i++
-				} else if r == braceType[0] && !b.isLocInStringOrComment(Loc{x, y}){
-					i--
-					if i == 0 {
-						return Loc{x, y}, true
-					}
-				}
-			}
-		}
+		return b.FindOpeningBrace(braceType, start)
 	}
 	return start, false
 }