combined findUp and findDown to findNext

internal/buffer/search.go

@@ -50,7 +50,7 @@ func findLineParams(b *Buffer, start, end Loc, i int) ([]byte, int, int) {
 	return l, charpos, padMode
 }
 
-func (b *Buffer) findDown(r *regexp.Regexp, start, end Loc) ([2]Loc, bool) {
+func (b *Buffer) findNext(r *regexp.Regexp, start, end Loc, down bool) ([2]Loc, bool) {
 	lastcn := util.CharacterCount(b.LineBytes(b.LinesNum() - 1))
 	if start.Y > b.LinesNum()-1 {
 		start.X = lastcn - 1
@@ -67,50 +67,27 @@ func (b *Buffer) findDown(r *regexp.Regexp, start, end Loc) ([2]Loc, bool) {
 
 	rPadded := padRegexp(r)
 
-	for i := start.Y; i <= end.Y; i++ {
-		l, charpos, padMode := findLineParams(b, start, end, i)
-
-		match := rPadded[padMode].FindIndex(l)
-
-		if match != nil {
-			start := Loc{charpos + util.RunePos(l, match[0]), i}
-			if padMode&padStart != 0 {
-				start = start.Move(1, b)
-			}
-			end := Loc{charpos + util.RunePos(l, match[1]), i}
-			if padMode&padEnd != 0 {
-				end = end.Move(-1, b)
-			}
-			return [2]Loc{start, end}, true
-		}
-	}
-	return [2]Loc{}, false
-}
-
-func (b *Buffer) findUp(r *regexp.Regexp, start, end Loc) ([2]Loc, bool) {
-	lastcn := util.CharacterCount(b.LineBytes(b.LinesNum() - 1))
-	if start.Y > b.LinesNum()-1 {
-		start.X = lastcn - 1
-	}
-	if end.Y > b.LinesNum()-1 {
-		end.X = lastcn
-	}
-	start.Y = util.Clamp(start.Y, 0, b.LinesNum()-1)
-	end.Y = util.Clamp(end.Y, 0, b.LinesNum()-1)
-
-	if start.GreaterThan(end) {
-		start, end = end, start
+	var i0, i1, is int
+	if down {
+		i0, i1, is = start.Y, end.Y, 1
+	} else {
+		i0, i1, is = end.Y, start.Y, -1
 	}
 
-	rPadded := padRegexp(r)
-
-	for i := end.Y; i >= start.Y; i-- {
+	for i := i0; is*i <= is*i1; i += is {
 		l, charpos, padMode := findLineParams(b, start, end, i)
 
-		allMatches := rPadded[padMode].FindAllIndex(l, -1)
+		var match []int
+		if down {
+			match = rPadded[padMode].FindIndex(l)
+		} else {
+			allMatches := rPadded[padMode].FindAllIndex(l, -1)
+			if allMatches != nil {
+				match = allMatches[len(allMatches)-1]
+			}
+		}
 
-		if allMatches != nil {
-			match := allMatches[len(allMatches)-1]
+		if match != nil {
 			start := Loc{charpos + util.RunePos(l, match[0]), i}
 			if padMode&padStart != 0 {
 				start = start.Move(1, b)
@@ -154,14 +131,14 @@ func (b *Buffer) FindNext(s string, start, end, from Loc, down bool, useRegex bo
 	var found bool
 	var l [2]Loc
 	if down {
-		l, found = b.findDown(r, from, end)
+		l, found = b.findNext(r, from, end, true)
 		if !found {
-			l, found = b.findDown(r, start, end)
+			l, found = b.findNext(r, start, end, true)
 		}
 	} else {
-		l, found = b.findUp(r, from, start)
+		l, found = b.findNext(r, from, start, false)
 		if !found {
-			l, found = b.findUp(r, end, start)
+			l, found = b.findNext(r, end, start, false)
 		}
 	}
 	return l, found, nil