Search and replace within a selection

Closes #1098

internal/buffer/loc.go

@@ -102,7 +102,7 @@ func (l Loc) left(buf *LineArray) Loc {
 	return res
 }
 
-// Move moves the cursor n characters to the left or right
+// MoveLA moves the cursor n characters to the left or right
 // It moves the cursor left if n is negative
 func (l Loc) MoveLA(n int, buf *LineArray) Loc {
 	if n > 0 {
@@ -117,9 +117,12 @@ func (l Loc) MoveLA(n int, buf *LineArray) Loc {
 	return l
 }
 
-func (l Loc) Diff(a, b Loc, buf *Buffer) int {
-	return DiffLA(a, b, buf.LineArray)
+// Diff returns the difference between two locs
+func (l Loc) Diff(b Loc, buf *Buffer) int {
+	return DiffLA(l, b, buf.LineArray)
 }
+
+// Move moves a loc n characters
 func (l Loc) Move(n int, buf *Buffer) Loc {
 	return l.MoveLA(n, buf.LineArray)
 }

internal/buffer/search.go

@@ -120,24 +120,27 @@ func (b *Buffer) FindNext(s string, start, end, from Loc, down bool, useRegex bo
 	if down {
 		l, found = b.findDown(r, from, end)
 		if !found {
-			l, found = b.findDown(r, start, from)
+			l, found = b.findDown(r, start, end)
 		}
 	} else {
 		l, found = b.findUp(r, from, start)
 		if !found {
-			l, found = b.findUp(r, end, from)
+			l, found = b.findUp(r, end, start)
 		}
 	}
 	return l, found, nil
 }
 
 // ReplaceRegex replaces all occurrences of 'search' with 'replace' in the given area
-// and returns the number of replacements made
-func (b *Buffer) ReplaceRegex(start, end Loc, search *regexp.Regexp, replace []byte) int {
+// and returns the number of replacements made and the number of runes
+// added or removed
+func (b *Buffer) ReplaceRegex(start, end Loc, search *regexp.Regexp, replace []byte) (int, int) {
 	if start.GreaterThan(end) {
 		start, end = end, start
 	}
 
+	netrunes := 0
+
 	found := 0
 	var deltas []Delta
 	for i := start.Y; i <= end.Y; i++ {
@@ -160,6 +163,7 @@ func (b *Buffer) ReplaceRegex(start, end Loc, search *regexp.Regexp, replace []b
 				result = search.Expand(result, replace, in, submatches)
 			}
 			found++
+			netrunes += utf8.RuneCount(in) - utf8.RuneCount(result)
 			return result
 		})
 
@@ -170,5 +174,5 @@ func (b *Buffer) ReplaceRegex(start, end Loc, search *regexp.Regexp, replace []b
 	}
 	b.MultipleReplace(deltas)
 
-	return found
+	return found, netrunes
 }