Code cleanup (#1640)

- Replaced time.Now().Sub() with time.Since()
- Replaced unnecessary string/byte slice conversions
- Removed obsolete return and value assignment in range loop

src/history.go

@@ -59,7 +59,7 @@ func (h *History) append(line string) error {
 
 	lines := append(h.lines[:len(h.lines)-1], line)
 	if len(lines) > h.maxSize {
-		lines = lines[len(lines)-h.maxSize : len(lines)]
+		lines = lines[len(lines)-h.maxSize:]
 	}
 	h.lines = append(lines, "")
 	return ioutil.WriteFile(h.path, []byte(strings.Join(h.lines, "\n")), 0600)

src/matcher.go

@@ -207,13 +207,13 @@ func (m *Matcher) scan(request MatchRequest) (*Merger, bool) {
 			return nil, wait()
 		}
 
-		if time.Now().Sub(startedAt) > progressMinDuration {
+		if time.Since(startedAt) > progressMinDuration {
 			m.eventBox.Set(EvtSearchProgress, float32(count)/float32(numChunks))
 		}
 	}
 
 	partialResults := make([][]Result, numSlices)
-	for _ = range slices {
+	for range slices {
 		partialResult := <-resultChan
 		partialResults[partialResult.index] = partialResult.matches
 	}

src/terminal.go

@@ -1532,7 +1532,7 @@ func (t *Terminal) Loop() {
 					cmd.Wait()
 					finishChan <- true
 					if out.Len() > 0 || !<-updateChan {
-						t.reqBox.Set(reqPreviewDisplay, string(out.Bytes()))
+						t.reqBox.Set(reqPreviewDisplay, out.String())
 					}
 				} else {
 					t.reqBox.Set(reqPreviewDisplay, "")

src/tokenizer.go

@@ -238,7 +238,7 @@ func Transform(tokens []Token, withNth []Range) []Token {
 			for _, part := range parts {
 				output.WriteString(part.ToString())
 			}
-			merged = util.ToChars([]byte(output.String()))
+			merged = util.ToChars(output.Bytes())
 		}
 
 		var prefixLength int32

src/tui/light.go

@@ -547,7 +547,7 @@ func (r *LightRenderer) mouseSequence(sz *int) Event {
 			r.prevDownTime = now
 		} else {
 			if len(r.clickY) > 1 && r.clickY[0] == r.clickY[1] &&
-				time.Now().Sub(r.prevDownTime) < doubleClickDuration {
+				time.Since(r.prevDownTime) < doubleClickDuration {
 				double = true
 			}
 		}

src/util/chars.go

@@ -169,7 +169,6 @@ func (chars *Chars) CopyRunes(dest []rune) {
 	for idx, b := range chars.slice[:len(dest)] {
 		dest[idx] = rune(b)
 	}
-	return
 }
 
 func (chars *Chars) Prepend(prefix string) {