0.15.4

This is a breaking change, but I believe it makes much more sense. It is
almost impossible to predict which entries will be filtered out due to
a fuzzy inverse term. You can still perform inverse-fuzzy-match by
prepending `!'` to the term.

| Token    | Match type                 | Description                       |
| -------- | -------------------------- | --------------------------------- |
| `sbtrkt` | fuzzy-match                | Items that match `sbtrkt`         |
| `^music` | prefix-exact-match         | Items that start with `music`     |
| `.mp3$`  | suffix-exact-match         | Items that end with `.mp3`        |
| `'wild`  | exact-match (quoted)       | Items that include `wild`         |
| `!fire`  | inverse-exact-match        | Items that do not include `fire`  |
| `!.mp3$` | inverse-suffix-exact-match | Items that do not end with `.mp3` |

CHANGELOG.md

@@ -1,6 +1,35 @@
 CHANGELOG
 =========
 
+0.15.4
+------
+- Added support for range expression in preview and execute action
+    - e.g. `ls -l | fzf --preview="echo user={3} when={-4..-2}; cat {-1}" --header-lines=1`
+    - `{q}` will be replaced to the single-quoted string of the current query
+- Fixed to properly handle unicode whitespace characters
+- Display scroll indicator in preview window
+- Inverse search term will use exact matcher by default
+    - This is a breaking change, but I believe it makes much more sense. It is
+      almost impossible to predict which entries will be filtered out due to
+      a fuzzy inverse term. You can still perform inverse-fuzzy-match by
+      prepending `!'` to the term.
+
+0.15.3
+------
+- Added support for more ANSI attributes: dim, underline, blink, and reverse
+- Fixed race condition in `toggle-preview`
+
+0.15.2
+------
+- Preview window is now scrollable
+    - With mouse scroll or with bindable actions
+        - `preview-up`
+        - `preview-down`
+        - `preview-page-up`
+        - `preview-page-down`
+- Updated ANSI processor to support high intensity colors and ignore
+  some VT100-related escape sequences
+
 0.15.1
 ------
 - Fixed panic when the pattern occurs after 2^15-th column

README.md

@@ -113,16 +113,16 @@ vim $(fzf)
 
 Unless otherwise specified, fzf starts in "extended-search mode" where you can
 type in multiple search terms delimited by spaces. e.g. `^music .mp3$ sbtrkt
-!rmx`
+!fire`
 
 | Token    | Match type                 | Description                       |
-| -------- | -------------------- | -------------------------------- |
+| -------- | -------------------------- | --------------------------------- |
 | `sbtrkt` | fuzzy-match                | Items that match `sbtrkt`         |
 | `^music` | prefix-exact-match         | Items that start with `music`     |
 | `.mp3$`  | suffix-exact-match         | Items that end with `.mp3`        |
 | `'wild`  | exact-match (quoted)       | Items that include `wild`         |
-| `!rmx`   | inverse-fuzzy-match  | Items that do not match `rmx`    |
+| `!fire`  | inverse-exact-match        | Items that do not include `fire`  |
-| `!'fire` | inverse-exact-match  | Items that do not include `fire` |
+| `!.mp3$` | inverse-suffix-exact-match | Items that do not end with `.mp3` |
 
 If you don't prefer fuzzy matching and do not wish to "quote" every word,
 start fzf with `-e` or `--exact` option. Note that when  `--exact` is set,
@@ -305,7 +305,7 @@ If you have set up fzf for Vim, `:FZF` command will be added.
 :FZF ~
 
 " With options
-:FZF --no-sort -m /tmp
+:FZF --no-sort --reverse --inline-info /tmp
 
 " Bang version starts in fullscreen instead of using tmux pane or Neovim split
 :FZF!

install

@@ -2,8 +2,8 @@
 
 set -u
 
-[[ "$@" =~ --pre ]] && version=0.15.1 pre=1 ||
+[[ "$@" =~ --pre ]] && version=0.15.4 pre=1 ||
-                       version=0.15.1 pre=0
+                       version=0.15.4 pre=0
 
 auto_completion=
 key_bindings=

man/man1/fzf-tmux.1

@@ -21,7 +21,7 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 ..
-.TH fzf-tmux 1 "Sep 2016" "fzf 0.15.1" "fzf-tmux - open fzf in tmux split pane"
+.TH fzf-tmux 1 "Oct 2016" "fzf 0.15.4" "fzf-tmux - open fzf in tmux split pane"
 
 .SH NAME
 fzf-tmux - open fzf in tmux split pane

man/man1/fzf.1

@@ -21,7 +21,7 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 ..
-.TH fzf 1 "Sep 2016" "fzf 0.15.1" "fzf - a command-line fuzzy finder"
+.TH fzf 1 "Oct 2016" "fzf 0.15.4" "fzf - a command-line fuzzy finder"
 
 .SH NAME
 fzf - a command-line fuzzy finder
@@ -232,11 +232,17 @@ automatically truncated when the number of the lines exceeds the value.
 .TP
 .BI "--preview=" "COMMAND"
 Execute the given command for the current line and display the result on the
-preview window. \fB{}\fR is the placeholder for the quoted string of the
+preview window. \fB{}\fR in the command is the placeholder that is replaced to
-current line.
+the single-quoted string of the current line. To transform the replacement
+string, specify field index expressions between the braces (See \fBFIELD INDEX
+EXPRESSION\fR for the details). Also, \fB{q}\fR is replaced to the current
+query string.
 
 .RS
 e.g. \fBfzf --preview="head -$LINES {}"\fR
+     \fBls -l | fzf --preview="echo user={3} when={-4..-2}; cat {-1}" --header-lines=1\fR
+
+Note that you can escape a placeholder pattern by prepending a backslash.
 .RE
 .TP
 .BI "--preview-window=" "[POSITION][:SIZE[%]][:hidden]"
@@ -358,7 +364,7 @@ with the given string. An anchored-match term is also an exact-match term.
 
 .SS Negation
 If a term is prefixed by \fB!\fR, fzf will exclude the lines that satisfy the
-term from the result.
+term from the result. In this case, fzf performs exact match by default.
 
 .SS Exact-match by default
 If you don't prefer fuzzy matching and do not wish to "quote" (prefixing with
@@ -434,6 +440,10 @@ e.g. \fBfzf --bind=ctrl-j:accept,ctrl-k:kill-line\fR
     \fBnext-history\fR          (\fIctrl-n\fR on \fB--history\fR)
     \fBpage-down\fR             \fIpgdn\fR
     \fBpage-up\fR               \fIpgup\fR
+    \fBpreview-down\fR
+    \fBpreview-up\fR
+    \fBpreview-page-down\fR
+    \fBpreview-page-up\fR
     \fBprevious-history\fR      (\fIctrl-p\fR on \fB--history\fR)
     \fBprint-query\fR           (print query and exit)
     \fBselect-all\fR
@@ -456,9 +466,11 @@ binding \fBenter\fR key to \fBless\fR command like follows.
 
     \fBfzf --bind "enter:execute(less {})"\fR
 
-\fB{}\fR is the placeholder for the quoted string of the current line.
+You can use the same placeholder expressions as in \fB--preview\fR.
-If the command contains parentheses, you can use any of the following
+
-alternative notations to avoid parse errors.
+If the command contains parentheses, fzf may fail to parse the expression. In
+that case, you can use any of the following alternative notations to avoid
+parse errors.
 
     \fBexecute[...]\fR
     \fBexecute~...~\fR
@@ -477,7 +489,7 @@ alternative notations to avoid parse errors.
 .RS
 This is the special form that frees you from parse errors as it does not expect
 the closing character. The catch is that it should be the last one in the
-comma-separated list.
+comma-separated list of key-action pairs.
 .RE
 
 \fBexecute-multi(...)\fR is an alternative action that executes the command

plugin/fzf.vim

@@ -558,11 +558,15 @@ let s:default_action = {
 
 function! s:cmd(bang, ...) abort
   let args = copy(a:000)
-  let opts = {}
+  let opts = { 'options': '--multi ' }
   if len(args) && isdirectory(expand(args[-1]))
-    let opts.dir = substitute(remove(args, -1), '\\\(["'']\)', '\1', 'g')
+    let opts.dir = substitute(substitute(remove(args, -1), '\\\(["'']\)', '\1', 'g'), '/*$', '/', '')
+    let opts.options .= ' --prompt '.shellescape(opts.dir)
+  else
+    let opts.options .= ' --prompt '.shellescape(pathshorten(getcwd()).'/')
   endif
-  call fzf#run(fzf#wrap('FZF', extend({'options': join(args)}, opts), a:bang))
+  let opts.options .= ' '.join(args)
+  call fzf#run(fzf#wrap('FZF', opts, a:bang))
 endfunction
 
 command! -nargs=* -complete=dir -bang FZF call s:cmd(<bang>0, <f-args>)

shell/completion.bash

@@ -32,7 +32,7 @@ fi
 
 _fzf_orig_completion_filter() {
   sed 's/^\(.*-F\) *\([^ ]*\).* \([^ ]*\)$/export _fzf_orig_completion_\3="\1 %s \3 #\2";/' |
-  awk -F= '{gsub(/[^a-z0-9_= ;]/, "_", $1); print $1"="$2}'
+  awk -F= '{gsub(/[^A-Za-z0-9_= ;]/, "_", $1); print $1"="$2}'
 }
 
 _fzf_opts_completion() {
@@ -117,7 +117,7 @@ _fzf_handle_dynamic_completion() {
 __fzf_generic_path_completion() {
   local cur base dir leftover matches trigger cmd fzf
   [ "${FZF_TMUX:-1}" != 0 ] && fzf="fzf-tmux -d ${FZF_TMUX_HEIGHT:-40%}" || fzf="fzf"
-  cmd=$(echo "${COMP_WORDS[0]}" | sed 's/[^a-z0-9_=]/_/g')
+  cmd="${COMP_WORDS[0]//[^A-Za-z0-9_=]/_}"
   COMPREPLY=()
   trigger=${FZF_COMPLETION_TRIGGER-'**'}
   cur="${COMP_WORDS[COMP_CWORD]}"
@@ -162,7 +162,7 @@ _fzf_complete() {
   type -t "$post" > /dev/null 2>&1 || post=cat
   [ "${FZF_TMUX:-1}" != 0 ] && fzf="fzf-tmux -d ${FZF_TMUX_HEIGHT:-40%}" || fzf="fzf"
 
-  cmd=$(echo "${COMP_WORDS[0]}" | sed 's/[^a-z0-9_=]/_/g')
+  cmd="${COMP_WORDS[0]//[^A-Za-z0-9_=]/_}"
   trigger=${FZF_COMPLETION_TRIGGER-'**'}
   cur="${COMP_WORDS[COMP_CWORD]}"
   if [[ "$cur" == *"$trigger" ]]; then
@@ -277,7 +277,7 @@ _fzf_defc() {
   cmd="$1"
   func="$2"
   opts="$3"
-  orig_var="_fzf_orig_completion_$cmd"
+  orig_var="_fzf_orig_completion_${cmd//[^A-Za-z0-9_]/_}"
   orig="${!orig_var}"
   if [ -n "$orig" ]; then
     printf -v def "$orig" "$func"

src/ansi.go

@@ -6,6 +6,8 @@ import (
 	"strconv"
 	"strings"
 	"unicode/utf8"
+
+	"github.com/junegunn/fzf/src/curses"
 )
 
 type ansiOffset struct {
@@ -16,24 +18,24 @@ type ansiOffset struct {
 type ansiState struct {
 	fg   int
 	bg   int
-	bold bool
+	attr curses.Attr
 }
 
 func (s *ansiState) colored() bool {
-	return s.fg != -1 || s.bg != -1 || s.bold
+	return s.fg != -1 || s.bg != -1 || s.attr > 0
 }
 
 func (s *ansiState) equals(t *ansiState) bool {
 	if t == nil {
 		return !s.colored()
 	}
-	return s.fg == t.fg && s.bg == t.bg && s.bold == t.bold
+	return s.fg == t.fg && s.bg == t.bg && s.attr == t.attr
 }
 
 var ansiRegex *regexp.Regexp
 
 func init() {
-	ansiRegex = regexp.MustCompile("\x1b\\[[0-9;]*[mK]")
+	ansiRegex = regexp.MustCompile("\x1b.[0-9;]*.")
 }
 
 func extractColor(str string, state *ansiState, proc func(string, *ansiState) bool) (string, *[]ansiOffset, *ansiState) {
@@ -94,11 +96,11 @@ func interpretCode(ansiCode string, prevState *ansiState) *ansiState {
 	// State
 	var state *ansiState
 	if prevState == nil {
-		state = &ansiState{-1, -1, false}
+		state = &ansiState{-1, -1, 0}
 	} else {
-		state = &ansiState{prevState.fg, prevState.bg, prevState.bold}
+		state = &ansiState{prevState.fg, prevState.bg, prevState.attr}
 	}
-	if ansiCode[len(ansiCode)-1] == 'K' {
+	if ansiCode[1] != '[' || ansiCode[len(ansiCode)-1] != 'm' {
 		return state
 	}
 
@@ -108,7 +110,7 @@ func interpretCode(ansiCode string, prevState *ansiState) *ansiState {
 	init := func() {
 		state.fg = -1
 		state.bg = -1
-		state.bold = false
+		state.attr = 0
 		state256 = 0
 	}
 
@@ -132,7 +134,15 @@ func interpretCode(ansiCode string, prevState *ansiState) *ansiState {
 				case 49:
 					state.bg = -1
 				case 1:
-					state.bold = true
+					state.attr = curses.Bold
+				case 2:
+					state.attr = curses.Dim
+				case 4:
+					state.attr = curses.Underline
+				case 5:
+					state.attr = curses.Blink
+				case 7:
+					state.attr = curses.Reverse
 				case 0:
 					init()
 				default:
@@ -140,6 +150,10 @@ func interpretCode(ansiCode string, prevState *ansiState) *ansiState {
 						state.fg = num - 30
 					} else if num >= 40 && num <= 47 {
 						state.bg = num - 40
+					} else if num >= 90 && num <= 97 {
+						state.fg = num - 90 + 8
+					} else if num >= 100 && num <= 107 {
+						state.bg = num - 100 + 8
 					}
 				}
 			case 1:

src/ansi_test.go

@@ -3,13 +3,19 @@ package fzf
 import (
 	"fmt"
 	"testing"
+
+	"github.com/junegunn/fzf/src/curses"
 )
 
 func TestExtractColor(t *testing.T) {
 	assert := func(offset ansiOffset, b int32, e int32, fg int, bg int, bold bool) {
+		var attr curses.Attr
+		if bold {
+			attr = curses.Bold
+		}
 		if offset.offset[0] != b || offset.offset[1] != e ||
-			offset.color.fg != fg || offset.color.bg != bg || offset.color.bold != bold {
+			offset.color.fg != fg || offset.color.bg != bg || offset.color.attr != attr {
-			t.Error(offset, b, e, fg, bg, bold)
+			t.Error(offset, b, e, fg, bg, attr)
 		}
 	}
 
@@ -121,7 +127,7 @@ func TestExtractColor(t *testing.T) {
 		if len(*offsets) != 1 {
 			t.Fail()
 		}
-		if state.fg != 2 || state.bg != -1 || !state.bold {
+		if state.fg != 2 || state.bg != -1 || state.attr == 0 {
 			t.Fail()
 		}
 		assert((*offsets)[0], 6, 11, 2, -1, true)
@@ -132,7 +138,7 @@ func TestExtractColor(t *testing.T) {
 		if len(*offsets) != 1 {
 			t.Fail()
 		}
-		if state.fg != 2 || state.bg != -1 || !state.bold {
+		if state.fg != 2 || state.bg != -1 || state.attr == 0 {
 			t.Fail()
 		}
 		assert((*offsets)[0], 0, 11, 2, -1, true)
@@ -143,7 +149,7 @@ func TestExtractColor(t *testing.T) {
 		if len(*offsets) != 2 {
 			t.Fail()
 		}
-		if state.fg != 200 || state.bg != 100 || state.bold {
+		if state.fg != 200 || state.bg != 100 || state.attr > 0 {
 			t.Fail()
 		}
 		assert((*offsets)[0], 0, 6, 2, -1, true)

src/constants.go

@@ -8,7 +8,7 @@ import (
 
 const (
 	// Current version
-	version = "0.15.1"
+	version = "0.15.4"
 
 	// Core
 	coordinatorDelayMax  time.Duration = 100 * time.Millisecond

src/curses/curses.go

@@ -23,6 +23,16 @@ import (
 	"unicode/utf8"
 )
 
+const (
+	Bold      = C.A_BOLD
+	Dim       = C.A_DIM
+	Blink     = C.A_BLINK
+	Reverse   = C.A_REVERSE
+	Underline = C.A_UNDERLINE
+)
+
+type Attr C.int
+
 // Types of user action
 const (
 	Rune = iota
@@ -158,7 +168,7 @@ type MouseEvent struct {
 var (
 	_buf          []byte
 	_in           *os.File
-	_color        func(int, bool) C.int
+	_color        func(int, Attr) C.int
 	_colorMap     map[int]int
 	_prevDownTime time.Time
 	_clickY       []int
@@ -183,7 +193,7 @@ type Window struct {
 func NewWindow(top int, left int, width int, height int, border bool) *Window {
 	win := C.newwin(C.int(height), C.int(width), C.int(top), C.int(left))
 	if border {
-		attr := _color(ColBorder, false)
+		attr := _color(ColBorder, 0)
 		C.wattron(win, attr)
 		C.box(win, 0, 0)
 		C.wattroff(win, attr)
@@ -266,22 +276,19 @@ func init() {
 		Border:       145}
 }
 
-func attrColored(pair int, bold bool) C.int {
+func attrColored(pair int, a Attr) C.int {
 	var attr C.int
 	if pair > ColNormal {
 		attr = C.COLOR_PAIR(C.int(pair))
 	}
-	if bold {
+	return attr | C.int(a)
-		attr = attr | C.A_BOLD
-	}
-	return attr
 }
 
-func attrMono(pair int, bold bool) C.int {
+func attrMono(pair int, a Attr) C.int {
 	var attr C.int
 	switch pair {
 	case ColCurrent:
-		if bold {
+		if a&C.A_BOLD == C.A_BOLD {
 			attr = C.A_REVERSE
 		}
 	case ColMatch:
@@ -289,7 +296,7 @@ func attrMono(pair int, bold bool) C.int {
 	case ColCurrentMatch:
 		attr = C.A_UNDERLINE | C.A_REVERSE
 	}
-	if bold {
+	if a&C.A_BOLD == C.A_BOLD {
 		attr = attr | C.A_BOLD
 	}
 	return attr
@@ -648,8 +655,8 @@ func (w *Window) Print(text string) {
 	}, text)))
 }
 
-func (w *Window) CPrint(pair int, bold bool, text string) {
+func (w *Window) CPrint(pair int, a Attr, text string) {
-	attr := _color(pair, bold)
+	attr := _color(pair, a)
 	C.wattron(w.win, attr)
 	w.Print(text)
 	C.wattroff(w.win, attr)
@@ -675,8 +682,8 @@ func (w *Window) Fill(str string) bool {
 	return C.waddstr(w.win, C.CString(str)) == C.OK
 }
 
-func (w *Window) CFill(str string, fg int, bg int, bold bool) bool {
+func (w *Window) CFill(str string, fg int, bg int, a Attr) bool {
-	attr := _color(PairFor(fg, bg), bold)
+	attr := _color(PairFor(fg, bg), a)
 	C.wattron(w.win, attr)
 	ret := w.Fill(str)
 	C.wattroff(w.win, attr)

src/options.go

@@ -663,6 +663,14 @@ func parseKeymap(keymap map[int]actionType, execmap map[int]string, str string)
 			keymap[key] = actTogglePreview
 		case "toggle-sort":
 			keymap[key] = actToggleSort
+		case "preview-up":
+			keymap[key] = actPreviewUp
+		case "preview-down":
+			keymap[key] = actPreviewDown
+		case "preview-page-up":
+			keymap[key] = actPreviewPageUp
+		case "preview-page-down":
+			keymap[key] = actPreviewPageDown
 		default:
 			if isExecuteAction(actLower) {
 				var offset int

src/pattern.go

@@ -163,12 +163,13 @@ func parseTerms(fuzzy bool, caseMode Case, str string) []termSet {
 
 		if strings.HasPrefix(text, "!") {
 			inv = true
+			typ = termExact
 			text = text[1:]
 		}
 
 		if strings.HasPrefix(text, "'") {
 			// Flip exactness
-			if fuzzy {
+			if fuzzy && !inv {
 				typ = termExact
 				text = text[1:]
 			} else {

src/pattern_test.go

@@ -22,15 +22,15 @@ func TestParseTermsExtended(t *testing.T) {
 		terms[1][0].typ != termExact || terms[1][0].inv ||
 		terms[2][0].typ != termPrefix || terms[2][0].inv ||
 		terms[3][0].typ != termSuffix || terms[3][0].inv ||
-		terms[4][0].typ != termFuzzy || !terms[4][0].inv ||
+		terms[4][0].typ != termExact || !terms[4][0].inv ||
-		terms[5][0].typ != termExact || !terms[5][0].inv ||
+		terms[5][0].typ != termFuzzy || !terms[5][0].inv ||
 		terms[6][0].typ != termPrefix || !terms[6][0].inv ||
 		terms[7][0].typ != termSuffix || !terms[7][0].inv ||
 		terms[7][1].typ != termEqual || terms[7][1].inv ||
 		terms[8][0].typ != termPrefix || terms[8][0].inv ||
 		terms[8][1].typ != termExact || terms[8][1].inv ||
 		terms[8][2].typ != termSuffix || terms[8][2].inv ||
-		terms[8][3].typ != termFuzzy || !terms[8][3].inv {
+		terms[8][3].typ != termExact || !terms[8][3].inv {
 		t.Errorf("%s", terms)
 	}
 	for idx, termSet := range terms[:8] {

src/result.go

@@ -3,6 +3,7 @@ package fzf
 import (
 	"math"
 	"sort"
+	"unicode"
 
 	"github.com/junegunn/fzf/src/curses"
 	"github.com/junegunn/fzf/src/util"
@@ -14,7 +15,7 @@ type Offset [2]int32
 type colorOffset struct {
 	offset [2]int32
 	color  int
-	bold   bool
+	attr   curses.Attr
 	index  int32
 }
 
@@ -62,7 +63,7 @@ func buildResult(item *Item, offsets []Offset, score int, trimLen int) *Result {
 				for idx := 0; idx < numChars; idx++ {
 					r := item.text.Get(idx)
 					whitePrefixLen = idx
-					if idx == minBegin || r != ' ' && r != '\t' {
+					if idx == minBegin || !unicode.IsSpace(r) {
 						break
 					}
 				}
@@ -91,14 +92,14 @@ func minRank() rank {
 	return rank{index: 0, points: [4]uint16{math.MaxUint16, 0, 0, 0}}
 }
 
-func (result *Result) colorOffsets(matchOffsets []Offset, color int, bold bool, current bool) []colorOffset {
+func (result *Result) colorOffsets(matchOffsets []Offset, color int, attr curses.Attr, current bool) []colorOffset {
 	itemColors := result.item.Colors()
 
 	if len(itemColors) == 0 {
 		var offsets []colorOffset
 		for _, off := range matchOffsets {
 
-			offsets = append(offsets, colorOffset{offset: [2]int32{off[0], off[1]}, color: color, bold: bold})
+			offsets = append(offsets, colorOffset{offset: [2]int32{off[0], off[1]}, color: color, attr: attr})
 		}
 		return offsets
 	}
@@ -142,7 +143,7 @@ func (result *Result) colorOffsets(matchOffsets []Offset, color int, bold bool,
 		if curr != 0 && idx > start {
 			if curr == -1 {
 				colors = append(colors, colorOffset{
-					offset: [2]int32{int32(start), int32(idx)}, color: color, bold: bold})
+					offset: [2]int32{int32(start), int32(idx)}, color: color, attr: attr})
 			} else {
 				ansi := itemColors[curr-1]
 				fg := ansi.color.fg
@@ -164,7 +165,7 @@ func (result *Result) colorOffsets(matchOffsets []Offset, color int, bold bool,
 				colors = append(colors, colorOffset{
 					offset: [2]int32{int32(start), int32(idx)},
 					color:  curses.PairFor(fg, bg),
-					bold:   ansi.color.bold || bold})
+					attr:   ansi.color.attr | attr})
 			}
 		}
 	}

src/result_test.go

@@ -97,16 +97,20 @@ func TestColorOffset(t *testing.T) {
 	item := Result{
 		item: &Item{
 			colors: &[]ansiOffset{
-				ansiOffset{[2]int32{0, 20}, ansiState{1, 5, false}},
+				ansiOffset{[2]int32{0, 20}, ansiState{1, 5, 0}},
-				ansiOffset{[2]int32{22, 27}, ansiState{2, 6, true}},
+				ansiOffset{[2]int32{22, 27}, ansiState{2, 6, curses.Bold}},
-				ansiOffset{[2]int32{30, 32}, ansiState{3, 7, false}},
+				ansiOffset{[2]int32{30, 32}, ansiState{3, 7, 0}},
-				ansiOffset{[2]int32{33, 40}, ansiState{4, 8, true}}}}}
+				ansiOffset{[2]int32{33, 40}, ansiState{4, 8, curses.Bold}}}}}
 	// [{[0 5] 9 false} {[5 15] 99 false} {[15 20] 9 false} {[22 25] 10 true} {[25 35] 99 false} {[35 40] 11 true}]
 
-	colors := item.colorOffsets(offsets, 99, false, true)
+	colors := item.colorOffsets(offsets, 99, 0, true)
 	assert := func(idx int, b int32, e int32, c int, bold bool) {
+		var attr curses.Attr
+		if bold {
+			attr = curses.Bold
+		}
 		o := colors[idx]
-		if o.offset[0] != b || o.offset[1] != e || o.color != c || o.bold != bold {
+		if o.offset[0] != b || o.offset[1] != e || o.color != c || o.attr != attr {
 			t.Error(o)
 		}
 	}

src/terminal.go

@@ -20,6 +20,12 @@ import (
 
 // import "github.com/pkg/profile"
 
+var placeholder *regexp.Regexp
+
+func init() {
+	placeholder = regexp.MustCompile("\\\\?(?:{[0-9,-.]*}|{q})")
+}
+
 type jumpMode int
 
 const (
@@ -28,6 +34,13 @@ const (
 	jumpAcceptEnabled
 )
 
+type previewer struct {
+	text    string
+	lines   int
+	offset  int
+	enabled bool
+}
+
 // Terminal represents terminal input/output
 type Terminal struct {
 	initDelay  time.Duration
@@ -44,6 +57,7 @@ type Terminal struct {
 	multi      bool
 	sort       bool
 	toggleSort bool
+	delimiter  Delimiter
 	expect     map[int]string
 	keymap     map[int]actionType
 	execmap    map[int]string
@@ -68,8 +82,7 @@ type Terminal struct {
 	selected   map[int32]selectedItem
 	reqBox     *util.EventBox
 	preview    previewOpts
-	previewing bool
+	previewer  previewer
-	previewTxt string
 	previewBox *util.EventBox
 	eventBox   *util.EventBox
 	mutex      sync.Mutex
@@ -81,16 +94,11 @@ type Terminal struct {
 
 type selectedItem struct {
 	at   time.Time
-	text string
+	item *Item
 }
 
 type byTimeOrder []selectedItem
 
-type previewRequest struct {
-	ok  bool
-	str string
-}
-
 func (a byTimeOrder) Len() int {
 	return len(a)
 }
@@ -119,6 +127,7 @@ const (
 	reqPrintQuery
 	reqPreviewEnqueue
 	reqPreviewDisplay
+	reqPreviewRefresh
 	reqQuit
 )
 
@@ -165,6 +174,10 @@ const (
 	actPrintQuery
 	actToggleSort
 	actTogglePreview
+	actPreviewUp
+	actPreviewDown
+	actPreviewPageUp
+	actPreviewPageDown
 	actPreviousHistory
 	actNextHistory
 	actExecute
@@ -256,6 +269,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		multi:      opts.Multi,
 		sort:       opts.Sort > 0,
 		toggleSort: opts.ToggleSort,
+		delimiter:  opts.Delimiter,
 		expect:     opts.Expect,
 		keymap:     opts.Keymap,
 		execmap:    opts.Execmap,
@@ -275,8 +289,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		selected:   make(map[int32]selectedItem),
 		reqBox:     util.NewEventBox(),
 		preview:    opts.Preview,
-		previewing: previewBox != nil && !opts.Preview.hidden,
+		previewer:  previewer{"", 0, 0, previewBox != nil && !opts.Preview.hidden},
-		previewTxt: "",
 		previewBox: previewBox,
 		eventBox:   eventBox,
 		mutex:      sync.Mutex{},
@@ -363,7 +376,7 @@ func (t *Terminal) output() bool {
 		}
 	} else {
 		for _, sel := range t.sortSelected() {
-			t.printer(sel.text)
+			t.printer(sel.item.AsString(t.ansi))
 		}
 	}
 	return found
@@ -516,24 +529,24 @@ func (t *Terminal) placeCursor() {
 
 func (t *Terminal) printPrompt() {
 	t.move(0, 0, true)
-	t.window.CPrint(C.ColPrompt, true, t.prompt)
+	t.window.CPrint(C.ColPrompt, C.Bold, t.prompt)
-	t.window.CPrint(C.ColNormal, true, string(t.input))
+	t.window.CPrint(C.ColNormal, C.Bold, string(t.input))
 }
 
 func (t *Terminal) printInfo() {
 	if t.inlineInfo {
 		t.move(0, displayWidth([]rune(t.prompt))+displayWidth(t.input)+1, true)
 		if t.reading {
-			t.window.CPrint(C.ColSpinner, true, " < ")
+			t.window.CPrint(C.ColSpinner, C.Bold, " < ")
 		} else {
-			t.window.CPrint(C.ColPrompt, true, " < ")
+			t.window.CPrint(C.ColPrompt, C.Bold, " < ")
 		}
 	} else {
 		t.move(1, 0, true)
 		if t.reading {
 			duration := int64(spinnerDuration)
 			idx := (time.Now().UnixNano() % (duration * int64(len(_spinner)))) / duration
-			t.window.CPrint(C.ColSpinner, true, _spinner[idx])
+			t.window.CPrint(C.ColSpinner, C.Bold, _spinner[idx])
 		}
 		t.move(1, 2, false)
 	}
@@ -552,7 +565,7 @@ func (t *Terminal) printInfo() {
 	if t.progress > 0 && t.progress < 100 {
 		output += fmt.Sprintf(" (%d%%)", t.progress)
 	}
-	t.window.CPrint(C.ColInfo, false, output)
+	t.window.CPrint(C.ColInfo, 0, output)
 }
 
 func (t *Terminal) printHeader() {
@@ -576,7 +589,7 @@ func (t *Terminal) printHeader() {
 			colors: colors}
 
 		t.move(line, 2, true)
-		t.printHighlighted(&Result{item: item}, false, C.ColHeader, 0, false)
+		t.printHighlighted(&Result{item: item}, 0, C.ColHeader, 0, false)
 	}
 }
 
@@ -610,21 +623,21 @@ func (t *Terminal) printItem(result *Result, i int, current bool) {
 	} else if current {
 		label = ">"
 	}
-	t.window.CPrint(C.ColCursor, true, label)
+	t.window.CPrint(C.ColCursor, C.Bold, label)
 	if current {
 		if selected {
-			t.window.CPrint(C.ColSelected, true, ">")
+			t.window.CPrint(C.ColSelected, C.Bold, ">")
 		} else {
-			t.window.CPrint(C.ColCurrent, true, " ")
+			t.window.CPrint(C.ColCurrent, C.Bold, " ")
 		}
-		t.printHighlighted(result, true, C.ColCurrent, C.ColCurrentMatch, true)
+		t.printHighlighted(result, C.Bold, C.ColCurrent, C.ColCurrentMatch, true)
 	} else {
 		if selected {
-			t.window.CPrint(C.ColSelected, true, ">")
+			t.window.CPrint(C.ColSelected, C.Bold, ">")
 		} else {
 			t.window.Print(" ")
 		}
-		t.printHighlighted(result, false, 0, C.ColMatch, false)
+		t.printHighlighted(result, 0, 0, C.ColMatch, false)
 	}
 }
 
@@ -680,7 +693,7 @@ func overflow(runes []rune, max int) bool {
 	return false
 }
 
-func (t *Terminal) printHighlighted(result *Result, bold bool, col1 int, col2 int, current bool) {
+func (t *Terminal) printHighlighted(result *Result, attr C.Attr, col1 int, col2 int, current bool) {
 	item := result.item
 
 	// Overflow
@@ -705,7 +718,7 @@ func (t *Terminal) printHighlighted(result *Result, bold bool, col1 int, col2 in
 		maxe = util.Max(maxe, int(offset[1]))
 	}
 
-	offsets := result.colorOffsets(charOffsets, col2, bold, current)
+	offsets := result.colorOffsets(charOffsets, col2, attr, current)
 	maxWidth := t.window.Width - 3
 	maxe = util.Constrain(maxe+util.Min(maxWidth/2-2, t.hscrollOff), 0, len(text))
 	if overflow(text, maxWidth) {
@@ -754,11 +767,11 @@ func (t *Terminal) printHighlighted(result *Result, bold bool, col1 int, col2 in
 		e := util.Constrain32(offset.offset[1], index, maxOffset)
 
 		substr, prefixWidth = processTabs(text[index:b], prefixWidth)
-		t.window.CPrint(col1, bold, substr)
+		t.window.CPrint(col1, attr, substr)
 
 		if b < e {
 			substr, prefixWidth = processTabs(text[b:e], prefixWidth)
-			t.window.CPrint(offset.color, offset.bold, substr)
+			t.window.CPrint(offset.color, offset.attr, substr)
 		}
 
 		index = e
@@ -768,18 +781,52 @@ func (t *Terminal) printHighlighted(result *Result, bold bool, col1 int, col2 in
 	}
 	if index < maxOffset {
 		substr, _ = processTabs(text[index:], prefixWidth)
-		t.window.CPrint(col1, bold, substr)
+		t.window.CPrint(col1, attr, substr)
 	}
 }
 
+func numLinesMax(str string, max int) int {
+	lines := 0
+	for lines < max {
+		idx := strings.Index(str, "\n")
+		if idx < 0 {
+			break
+		}
+		str = str[idx+1:]
+		lines++
+	}
+	return lines
+}
+
 func (t *Terminal) printPreview() {
+	if !t.isPreviewEnabled() {
+		return
+	}
 	t.pwindow.Erase()
-	extractColor(t.previewTxt, nil, func(str string, ansi *ansiState) bool {
+	skip := t.previewer.offset
+	extractColor(t.previewer.text, nil, func(str string, ansi *ansiState) bool {
+		if skip > 0 {
+			newlines := numLinesMax(str, skip)
+			if skip <= newlines {
+				for i := 0; i < skip; i++ {
+					str = str[strings.Index(str, "\n")+1:]
+				}
+				skip = 0
+			} else {
+				skip -= newlines
+				return true
+			}
+		}
 		if ansi != nil && ansi.colored() {
-			return t.pwindow.CFill(str, ansi.fg, ansi.bg, ansi.bold)
+			return t.pwindow.CFill(str, ansi.fg, ansi.bg, ansi.attr)
 		}
 		return t.pwindow.Fill(str)
 	})
+	if t.previewer.offset > 0 {
+		offset := fmt.Sprintf("%d/%d", t.previewer.offset+1, t.previewer.lines)
+		t.pwindow.Move(0, t.pwindow.Width-len(offset))
+		t.pwindow.CPrint(C.ColInfo, C.Reverse, offset)
+	}
 }
 
 func processTabs(runes []rune, prefixWidth int) (string, int) {
@@ -803,10 +850,8 @@ func (t *Terminal) printAll() {
 	t.printPrompt()
 	t.printInfo()
 	t.printHeader()
-	if t.isPreviewEnabled() {
 	t.printPreview()
 }
-}
 
 func (t *Terminal) refresh() {
 	if !t.suppress {
@@ -875,8 +920,60 @@ func quoteEntry(entry string) string {
 	return "'" + strings.Replace(entry, "'", "'\\''", -1) + "'"
 }
 
-func (t *Terminal) executeCommand(template string, replacement string) {
+func replacePlaceholder(template string, stripAnsi bool, delimiter Delimiter, query string, items []*Item) string {
-	command := strings.Replace(template, "{}", replacement, -1)
+	return placeholder.ReplaceAllStringFunc(template, func(match string) string {
+		// Escaped pattern
+		if match[0] == '\\' {
+			return match[1:]
+		}
+
+		// Current query
+		if match == "{q}" {
+			return quoteEntry(query)
+		}
+
+		replacements := make([]string, len(items))
+
+		if match == "{}" {
+			for idx, item := range items {
+				replacements[idx] = quoteEntry(item.AsString(stripAnsi))
+			}
+			return strings.Join(replacements, " ")
+		}
+
+		tokens := strings.Split(match[1:len(match)-1], ",")
+		ranges := make([]Range, len(tokens))
+		for idx, s := range tokens {
+			r, ok := ParseRange(&s)
+			if !ok {
+				// Invalid expression, just return the original string in the template
+				return match
+			}
+			ranges[idx] = r
+		}
+
+		for idx, item := range items {
+			chars := util.RunesToChars([]rune(item.AsString(stripAnsi)))
+			tokens := Tokenize(chars, delimiter)
+			trans := Transform(tokens, ranges)
+			str := string(joinTokens(trans))
+			if delimiter.str != nil {
+				str = strings.TrimSuffix(str, *delimiter.str)
+			} else if delimiter.regex != nil {
+				delims := delimiter.regex.FindAllStringIndex(str, -1)
+				if len(delims) > 0 && delims[len(delims)-1][1] == len(str) {
+					str = str[:delims[len(delims)-1][0]]
+				}
+			}
+			str = strings.TrimSpace(str)
+			replacements[idx] = quoteEntry(str)
+		}
+		return strings.Join(replacements, " ")
+	})
+}
+
+func (t *Terminal) executeCommand(template string, items []*Item) {
+	command := replacePlaceholder(template, t.ansi, t.delimiter, string(t.input), items)
 	cmd := util.ExecCommand(command)
 	cmd.Stdin = os.Stdin
 	cmd.Stdout = os.Stdout
@@ -891,11 +988,15 @@ func (t *Terminal) hasPreviewWindow() bool {
 }
 
 func (t *Terminal) isPreviewEnabled() bool {
-	return t.previewBox != nil && t.previewing
+	return t.previewBox != nil && t.previewer.enabled
+}
+
+func (t *Terminal) currentItem() *Item {
+	return t.merger.Get(t.cy).item
 }
 
 func (t *Terminal) current() string {
-	return t.merger.Get(t.cy).item.AsString(t.ansi)
+	return t.currentItem().AsString(t.ansi)
 }
 
 // Loop is called to start Terminal I/O
@@ -952,18 +1053,19 @@ func (t *Terminal) Loop() {
 	if t.hasPreviewWindow() {
 		go func() {
 			for {
-				request := previewRequest{false, ""}
+				var request *Item
 				t.previewBox.Wait(func(events *util.Events) {
 					for req, value := range *events {
 						switch req {
 						case reqPreviewEnqueue:
-							request = value.(previewRequest)
+							request = value.(*Item)
 						}
 					}
 					events.Clear()
 				})
-				if request.ok {
+				if request != nil {
-					command := strings.Replace(t.preview.command, "{}", quoteEntry(request.str), -1)
+					command := replacePlaceholder(t.preview.command,
+						t.ansi, t.delimiter, string(t.input), []*Item{request})
 					cmd := util.ExecCommand(command)
 					out, _ := cmd.CombinedOutput()
 					t.reqBox.Set(reqPreviewDisplay, string(out))
@@ -983,7 +1085,7 @@ func (t *Terminal) Loop() {
 	}
 
 	go func() {
-		focused := previewRequest{false, ""}
+		var focused *Item
 		for {
 			t.reqBox.Wait(func(events *util.Events) {
 				defer events.Clear()
@@ -1000,11 +1102,11 @@ func (t *Terminal) Loop() {
 					case reqList:
 						t.printList()
 						cnt := t.merger.Length()
-						var currentFocus previewRequest
+						var currentFocus *Item
 						if cnt > 0 && cnt > t.cy {
-							currentFocus = previewRequest{true, t.current()}
+							currentFocus = t.currentItem()
 						} else {
-							currentFocus = previewRequest{false, ""}
+							currentFocus = nil
 						}
 						if currentFocus != focused {
 							focused = currentFocus
@@ -1033,7 +1135,11 @@ func (t *Terminal) Loop() {
 						}
 						exit(exitNoMatch)
 					case reqPreviewDisplay:
-						t.previewTxt = value.(string)
+						t.previewer.text = value.(string)
+						t.previewer.lines = strings.Count(t.previewer.text, "\n")
+						t.previewer.offset = 0
+						t.printPreview()
+					case reqPreviewRefresh:
 						t.printPreview()
 					case reqPrintQuery:
 						C.Close()
@@ -1068,7 +1174,7 @@ func (t *Terminal) Loop() {
 		}
 		selectItem := func(item *Item) bool {
 			if _, found := t.selected[item.Index()]; !found {
-				t.selected[item.Index()] = selectedItem{time.Now(), item.AsString(t.ansi)}
+				t.selected[item.Index()] = selectedItem{time.Now(), item}
 				return true
 			}
 			return false
@@ -1085,6 +1191,11 @@ func (t *Terminal) Loop() {
 				req(reqInfo)
 			}
 		}
+		scrollPreview := func(amount int) {
+			t.previewer.offset = util.Constrain(
+				t.previewer.offset+amount, 0, t.previewer.lines-1)
+			req(reqPreviewRefresh)
+		}
 		for key, ret := range t.expect {
 			if keyMatch(key, event) {
 				t.pressed = ret
@@ -1100,16 +1211,15 @@ func (t *Terminal) Loop() {
 			case actIgnore:
 			case actExecute:
 				if t.cy >= 0 && t.cy < t.merger.Length() {
-					item := t.merger.Get(t.cy).item
+					t.executeCommand(t.execmap[mapkey], []*Item{t.currentItem()})
-					t.executeCommand(t.execmap[mapkey], quoteEntry(item.AsString(t.ansi)))
 				}
 			case actExecuteMulti:
 				if len(t.selected) > 0 {
-					sels := make([]string, len(t.selected))
+					sels := make([]*Item, len(t.selected))
 					for i, sel := range t.sortSelected() {
-						sels[i] = quoteEntry(sel.text)
+						sels[i] = sel.item
 					}
-					t.executeCommand(t.execmap[mapkey], strings.Join(sels, " "))
+					t.executeCommand(t.execmap[mapkey], sels)
 				} else {
 					return doAction(actExecute, mapkey)
 				}
@@ -1118,11 +1228,11 @@ func (t *Terminal) Loop() {
 				return false
 			case actTogglePreview:
 				if t.hasPreviewWindow() {
-					t.previewing = !t.previewing
+					t.previewer.enabled = !t.previewer.enabled
 					t.resizeWindows()
 					cnt := t.merger.Length()
-					if t.previewing && cnt > 0 && cnt > t.cy {
+					if t.previewer.enabled && cnt > 0 && cnt > t.cy {
-						t.previewBox.Set(reqPreviewEnqueue, previewRequest{true, t.current()})
+						t.previewBox.Set(reqPreviewEnqueue, t.currentItem())
 					}
 					req(reqList, reqInfo)
 				}
@@ -1131,6 +1241,22 @@ func (t *Terminal) Loop() {
 				t.eventBox.Set(EvtSearchNew, t.sort)
 				t.mutex.Unlock()
 				return false
+			case actPreviewUp:
+				if t.isPreviewEnabled() {
+					scrollPreview(-1)
+				}
+			case actPreviewDown:
+				if t.isPreviewEnabled() {
+					scrollPreview(1)
+				}
+			case actPreviewPageUp:
+				if t.isPreviewEnabled() {
+					scrollPreview(-t.pwindow.Height)
+				}
+			case actPreviewPageDown:
+				if t.isPreviewEnabled() {
+					scrollPreview(t.pwindow.Height)
+				}
 			case actBeginningOfLine:
 				t.cx = 0
 			case actBackwardChar:
@@ -1299,6 +1425,8 @@ func (t *Terminal) Loop() {
 						}
 						t.vmove(me.S)
 						req(reqList)
+					} else if t.isPreviewEnabled() && t.pwindow.Enclose(my, mx) {
+						scrollPreview(-me.S)
 					}
 				} else if t.window.Enclose(my, mx) {
 					mx -= t.window.Left

src/terminal_test.go

@@ -0,0 +1,73 @@
+package fzf
+
+import (
+	"regexp"
+	"testing"
+
+	"github.com/junegunn/fzf/src/util"
+)
+
+func newItem(str string) *Item {
+	bytes := []byte(str)
+	trimmed, _, _ := extractColor(str, nil, nil)
+	return &Item{origText: &bytes, text: util.RunesToChars([]rune(trimmed))}
+}
+
+func TestReplacePlaceholder(t *testing.T) {
+	items1 := []*Item{newItem("  foo'bar \x1b[31mbaz\x1b[m")}
+	items2 := []*Item{
+		newItem("foo'bar \x1b[31mbaz\x1b[m"),
+		newItem("FOO'BAR \x1b[31mBAZ\x1b[m")}
+
+	var result string
+	check := func(expected string) {
+		if result != expected {
+			t.Errorf("expected: %s, actual: %s", expected, result)
+		}
+	}
+
+	// {}, preserve ansi
+	result = replacePlaceholder("echo {}", false, Delimiter{}, "query", items1)
+	check("echo '  foo'\\''bar \x1b[31mbaz\x1b[m'")
+
+	// {}, strip ansi
+	result = replacePlaceholder("echo {}", true, Delimiter{}, "query", items1)
+	check("echo '  foo'\\''bar baz'")
+
+	// {}, with multiple items
+	result = replacePlaceholder("echo {}", true, Delimiter{}, "query", items2)
+	check("echo 'foo'\\''bar baz' 'FOO'\\''BAR BAZ'")
+
+	// {..}, strip leading whitespaces, preserve ansi
+	result = replacePlaceholder("echo {..}", false, Delimiter{}, "query", items1)
+	check("echo 'foo'\\''bar \x1b[31mbaz\x1b[m'")
+
+	// {..}, strip leading whitespaces, strip ansi
+	result = replacePlaceholder("echo {..}", true, Delimiter{}, "query", items1)
+	check("echo 'foo'\\''bar baz'")
+
+	// {q}
+	result = replacePlaceholder("echo {} {q}", true, Delimiter{}, "query", items1)
+	check("echo '  foo'\\''bar baz' 'query'")
+
+	// {q}, multiple items
+	result = replacePlaceholder("echo {}{q}{}", true, Delimiter{}, "query 'string'", items2)
+	check("echo 'foo'\\''bar baz' 'FOO'\\''BAR BAZ''query '\\''string'\\''''foo'\\''bar baz' 'FOO'\\''BAR BAZ'")
+
+	result = replacePlaceholder("echo {1}/{2}/{2,1}/{-1}/{-2}/{}/{..}/{n.t}/\\{}/\\{1}/\\{q}/{3}", true, Delimiter{}, "query", items1)
+	check("echo 'foo'\\''bar'/'baz'/'bazfoo'\\''bar'/'baz'/'foo'\\''bar'/'  foo'\\''bar baz'/'foo'\\''bar baz'/{n.t}/{}/{1}/{q}/''")
+
+	result = replacePlaceholder("echo {1}/{2}/{-1}/{-2}/{..}/{n.t}/\\{}/\\{1}/\\{q}/{3}", true, Delimiter{}, "query", items2)
+	check("echo 'foo'\\''bar' 'FOO'\\''BAR'/'baz' 'BAZ'/'baz' 'BAZ'/'foo'\\''bar' 'FOO'\\''BAR'/'foo'\\''bar baz' 'FOO'\\''BAR BAZ'/{n.t}/{}/{1}/{q}/'' ''")
+
+	// String delimiter
+	delim := "'"
+	result = replacePlaceholder("echo {}/{1}/{2}", true, Delimiter{str: &delim}, "query", items1)
+	check("echo '  foo'\\''bar baz'/'foo'/'bar baz'")
+
+	// Regex delimiter
+	regex := regexp.MustCompile("[oa]+")
+	// foo'bar baz
+	result = replacePlaceholder("echo {}/{1}/{3}/{2..3}", true, Delimiter{regex: regex}, "query", items1)
+	check("echo '  foo'\\''bar baz'/'f'/'r b'/''\\''bar b'")
+}

src/util/chars.go

@@ -1,6 +1,7 @@
 package util
 
 import (
+	"unicode"
 	"unicode/utf8"
 )
 
@@ -63,7 +64,7 @@ func (chars *Chars) TrimLength() int {
 	len := chars.Length()
 	for i = len - 1; i >= 0; i-- {
 		char := chars.Get(i)
-		if char != ' ' && char != '\t' {
+		if !unicode.IsSpace(char) {
 			break
 		}
 	}
@@ -75,7 +76,7 @@ func (chars *Chars) TrimLength() int {
 	var j int
 	for j = 0; j < len; j++ {
 		char := chars.Get(j)
-		if char != ' ' && char != '\t' {
+		if !unicode.IsSpace(char) {
 			break
 		}
 	}
@@ -86,7 +87,7 @@ func (chars *Chars) TrailingWhitespaces() int {
 	whitespaces := 0
 	for i := chars.Length() - 1; i >= 0; i-- {
 		char := chars.Get(i)
-		if char != ' ' && char != '\t' {
+		if !unicode.IsSpace(char) {
 			break
 		}
 		whitespaces++