Add --scheme=[default|path|history] option to choose scoring scheme

Close #2909
Close #2930

9 files changed, 107 insertions, 37 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 48dfb69e..f84735af 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,8 +1,18 @@
 CHANGELOG
 =========
 
-0.32.2
-------
+0.33.0
+------
+- Added `--scheme=[default|path|history]` option to choose scoring scheme
+    - (Experimental)
+    - We updated the scoring algorithm in 0.32.0, however we have learned that
+      this new scheme (`default`) is not always giving the optimal result
+    - `path`: Additional bonus point is only given the the characters after
+      path separator. You might want to choose this scheme if you have many
+      files with spaces in their paths.
+    - `history`: No additional bonus points are given so that we give more
+      weight to the chronological ordering. This is equivalent to the scoring
+      scheme before 0.32.0. This also sets `--tiebreak=index`.
 - ANSI color sequences with colon delimiters are now supported.
   ```sh
   printf "\e[38;5;208mOption 1\e[m\nOption 2" | fzf --ansi
diff --git a/man/man1/fzf-tmux.1 b/man/man1/fzf-tmux.1
index 282ada58..47a49c45 100644
--- a/man/man1/fzf-tmux.1
+++ b/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 "Aug 2022" "fzf 0.32.1" "fzf-tmux - open fzf in tmux split pane"
+.TH fzf-tmux 1 "Aug 2022" "fzf 0.33.0" "fzf-tmux - open fzf in tmux split pane"
 
 .SH NAME
 fzf-tmux - open fzf in tmux split pane
diff --git a/man/man1/fzf.1 b/man/man1/fzf.1
index 970ba08e..a6455cc2 100644
--- a/man/man1/fzf.1
+++ b/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 "Aug 2022" "fzf 0.32.2" "fzf - a command-line fuzzy finder"
+.TH fzf 1 "Aug 2022" "fzf 0.33.0" "fzf - a command-line fuzzy finder"
 
 .SH NAME
 fzf - a command-line fuzzy finder
@@ -51,6 +51,18 @@ Case-sensitive match
 .B "--literal"
 Do not normalize latin script letters for matching.
 .TP
+.BI "--scheme=" SCHEME
+Choose scoring scheme tailored for different types of input.
+
+.br
+.BR default "  Generic scoring scheme designed to work well with any type of input"
+.br
+.BR path "     Scoring scheme for paths (additional bonus point only after path separator)
+.br
+.BR history "  Scoring scheme for command history (no additional bonus points).
+         Sets \fB--tiebreak=index\fR as well.
+.br
+.TP
 .BI "--algo=" TYPE
 Fuzzy matching algorithm (default: v2)
 
diff --git a/shell/key-bindings.bash b/shell/key-bindings.bash
index 701cf5b0..f6797d49 100644
--- a/shell/key-bindings.bash
+++ b/shell/key-bindings.bash
@@ -50,7 +50,7 @@ __fzf_cd__() {
 
 __fzf_history__() {
   local output opts script
-  opts="--height ${FZF_TMUX_HEIGHT:-40%} --bind=ctrl-z:ignore $FZF_DEFAULT_OPTS -n2..,.. --tiebreak=index --bind=ctrl-r:toggle-sort $FZF_CTRL_R_OPTS +m --read0"
+  opts="--height ${FZF_TMUX_HEIGHT:-40%} --bind=ctrl-z:ignore $FZF_DEFAULT_OPTS -n2..,.. --scheme=history --bind=ctrl-r:toggle-sort $FZF_CTRL_R_OPTS +m --read0"
   script='BEGIN { getc; $/ = "\n\t"; $HISTCOUNT = $ENV{last_hist} + 1 } s/^[ *]//; print $HISTCOUNT - $. . "\t$_" if !$seen{$_}++'
   output=$(
     builtin fc -lnr -2147483648 |
diff --git a/shell/key-bindings.fish b/shell/key-bindings.fish
index 36b3aa34..5fd6f6b2 100644
--- a/shell/key-bindings.fish
+++ b/shell/key-bindings.fish
@@ -53,7 +53,7 @@ function fzf_key_bindings
   function fzf-history-widget -d "Show command history"
     test -n "$FZF_TMUX_HEIGHT"; or set FZF_TMUX_HEIGHT 40%
     begin
-      set -lx FZF_DEFAULT_OPTS "--height $FZF_TMUX_HEIGHT $FZF_DEFAULT_OPTS --tiebreak=index --bind=ctrl-r:toggle-sort,ctrl-z:ignore $FZF_CTRL_R_OPTS +m"
+      set -lx FZF_DEFAULT_OPTS "--height $FZF_TMUX_HEIGHT $FZF_DEFAULT_OPTS --scheme=history --bind=ctrl-r:toggle-sort,ctrl-z:ignore $FZF_CTRL_R_OPTS +m"
 
       set -l FISH_MAJOR (echo $version | cut -f1 -d.)
       set -l FISH_MINOR (echo $version | cut -f2 -d.)
diff --git a/shell/key-bindings.zsh b/shell/key-bindings.zsh
index b0b81f26..47ef17a7 100644
--- a/shell/key-bindings.zsh
+++ b/shell/key-bindings.zsh
@@ -98,7 +98,7 @@ fzf-history-widget() {
   local selected num
   setopt localoptions noglobsubst noposixbuiltins pipefail no_aliases 2> /dev/null
   selected=( $(fc -rl 1 | awk '{ cmd=$0; sub(/^[ \t]*[0-9]+\**[ \t]+/, "", cmd); if (!seen[cmd]++) print $0 }' |
-    FZF_DEFAULT_OPTS="--height ${FZF_TMUX_HEIGHT:-40%} $FZF_DEFAULT_OPTS -n2..,.. --tiebreak=index --bind=ctrl-r:toggle-sort,ctrl-z:ignore $FZF_CTRL_R_OPTS --query=${(qqq)LBUFFER} +m" $(__fzfcmd)) )
+    FZF_DEFAULT_OPTS="--height ${FZF_TMUX_HEIGHT:-40%} $FZF_DEFAULT_OPTS -n2..,.. --scheme=history --bind=ctrl-r:toggle-sort,ctrl-z:ignore $FZF_CTRL_R_OPTS --query=${(qqq)LBUFFER} +m" $(__fzfcmd)) )
   local ret=$?
   if [ -n "$selected" ]; then
     num=$selected[1]
diff --git a/src/algo/algo.go b/src/algo/algo.go
index 15214a68..50dd466c 100644
--- a/src/algo/algo.go
+++ b/src/algo/algo.go
@@ -80,6 +80,7 @@ Scoring criteria
 import (
 	"bytes"
 	"fmt"
+	"os"
 	"strings"
 	"unicode"
 	"unicode/utf8"
@@ -89,7 +90,8 @@ import (
 
 var DEBUG bool
 
-const delimiterChars = "/,:;|"
+var delimiterChars = "/,:;|"
+
 const whiteChars = " \t\n\v\f\r\x85\xA0"
 
 func indexAt(index int, max int, forward bool) int {
@@ -120,12 +122,6 @@ const (
 	// in web2 dictionary and my file system.
 	bonusBoundary = scoreMatch / 2
 
-	// Extra bonus for word boundary after whitespace character or beginning of the string
-	bonusBoundaryWhite = bonusBoundary + 2
-
-	// Extra bonus for word boundary after slash, colon, semi-colon, and comma
-	bonusBoundaryDelimiter = bonusBoundary + 1
-
 	// Although bonus point for non-word characters is non-contextual, we need it
 	// for computing bonus points for consecutive chunks starting with a non-word
 	// character.
@@ -149,6 +145,16 @@ const (
 	bonusFirstCharMultiplier = 2
 )
 
+var (
+	// Extra bonus for word boundary after whitespace character or beginning of the string
+	bonusBoundaryWhite int16 = bonusBoundary + 2
+
+	// Extra bonus for word boundary after slash, colon, semi-colon, and comma
+	bonusBoundaryDelimiter int16 = bonusBoundary + 1
+
+	initialCharClass charClass = charWhite
+)
+
 type charClass int
 
 const (
@@ -161,6 +167,29 @@ const (
 	charNumber
 )
 
+func Init(scheme string) bool {
+	switch scheme {
+	case "default":
+		bonusBoundaryWhite = bonusBoundary + 2
+		bonusBoundaryDelimiter = bonusBoundary + 1
+	case "path":
+		bonusBoundaryWhite = bonusBoundary
+		bonusBoundaryDelimiter = bonusBoundary + 1
+		if os.PathSeparator == '/' {
+			delimiterChars = "/"
+		} else {
+			delimiterChars = string([]rune{os.PathSeparator, '/'})
+		}
+		initialCharClass = charDelimiter
+	case "history":
+		bonusBoundaryWhite = bonusBoundary
+		bonusBoundaryDelimiter = bonusBoundary
+	default:
+		return false
+	}
+	return true
+}
+
 func posArray(withPos bool, len int) *[]int {
 	if withPos {
 		pos := make([]int, 0, len)
@@ -407,7 +436,7 @@ func FuzzyMatchV2(caseSensitive bool, normalize bool, forward bool, input *util.
 	// Phase 2. Calculate bonus for each point
 	maxScore, maxScorePos := int16(0), 0
 	pidx, lastIdx := 0, 0
-	pchar0, pchar, prevH0, prevClass, inGap := pattern[0], pattern[0], int16(0), charWhite, false
+	pchar0, pchar, prevH0, prevClass, inGap := pattern[0], pattern[0], int16(0), initialCharClass, false
 	Tsub := T[idx:]
 	H0sub, C0sub, Bsub := H0[idx:][:len(Tsub)], C0[idx:][:len(Tsub)], B[idx:][:len(Tsub)]
 	for off, char := range Tsub {
@@ -910,8 +939,8 @@ func EqualMatch(caseSensitive bool, normalize bool, forward bool, text *util.Cha
 		match = runesStr == string(pattern)
 	}
 	if match {
-		return Result{trimmedLen, trimmedLen + lenPattern, (scoreMatch+bonusBoundaryWhite)*lenPattern +
-			(bonusFirstCharMultiplier-1)*bonusBoundaryWhite}, nil
+		return Result{trimmedLen, trimmedLen + lenPattern, (scoreMatch+int(bonusBoundaryWhite))*lenPattern +
+			(bonusFirstCharMultiplier-1)*int(bonusBoundaryWhite)}, nil
 	}
 	return Result{-1, -1, 0}, nil
 }
diff --git a/src/algo/algo_test.go b/src/algo/algo_test.go
index 2dbe3833..a7c4e1d3 100644
--- a/src/algo/algo_test.go
+++ b/src/algo/algo_test.go
@@ -45,29 +45,29 @@ func TestFuzzyMatch(t *testing.T) {
 			assertMatch(t, fn, false, forward, "fooBarbaz1", "oBZ", 2, 9,
 				scoreMatch*3+bonusCamel123+scoreGapStart+scoreGapExtension*3)
 			assertMatch(t, fn, false, forward, "foo bar baz", "fbb", 0, 9,
-				scoreMatch*3+bonusBoundaryWhite*bonusFirstCharMultiplier+
-					bonusBoundaryWhite*2+2*scoreGapStart+4*scoreGapExtension)
+				scoreMatch*3+int(bonusBoundaryWhite)*bonusFirstCharMultiplier+
+					int(bonusBoundaryWhite)*2+2*scoreGapStart+4*scoreGapExtension)
 			assertMatch(t, fn, false, forward, "/AutomatorDocument.icns", "rdoc", 9, 13,
 				scoreMatch*4+bonusCamel123+bonusConsecutive*2)
 			assertMatch(t, fn, false, forward, "/man1/zshcompctl.1", "zshc", 6, 10,
-				scoreMatch*4+bonusBoundaryDelimiter*bonusFirstCharMultiplier+bonusBoundaryDelimiter*3)
+				scoreMatch*4+int(bonusBoundaryDelimiter)*bonusFirstCharMultiplier+int(bonusBoundaryDelimiter)*3)
 			assertMatch(t, fn, false, forward, "/.oh-my-zsh/cache", "zshc", 8, 13,
-				scoreMatch*4+bonusBoundary*bonusFirstCharMultiplier+bonusBoundary*2+scoreGapStart+bonusBoundaryDelimiter)
+				scoreMatch*4+bonusBoundary*bonusFirstCharMultiplier+bonusBoundary*2+scoreGapStart+int(bonusBoundaryDelimiter))
 			assertMatch(t, fn, false, forward, "ab0123 456", "12356", 3, 10,
 				scoreMatch*5+bonusConsecutive*3+scoreGapStart+scoreGapExtension)
 			assertMatch(t, fn, false, forward, "abc123 456", "12356", 3, 10,
 				scoreMatch*5+bonusCamel123*bonusFirstCharMultiplier+bonusCamel123*2+bonusConsecutive+scoreGapStart+scoreGapExtension)
 			assertMatch(t, fn, false, forward, "foo/bar/baz", "fbb", 0, 9,
-				scoreMatch*3+bonusBoundaryWhite*bonusFirstCharMultiplier+
-					bonusBoundaryDelimiter*2+2*scoreGapStart+4*scoreGapExtension)
+				scoreMatch*3+int(bonusBoundaryWhite)*bonusFirstCharMultiplier+
+					int(bonusBoundaryDelimiter)*2+2*scoreGapStart+4*scoreGapExtension)
 			assertMatch(t, fn, false, forward, "fooBarBaz", "fbb", 0, 7,
-				scoreMatch*3+bonusBoundaryWhite*bonusFirstCharMultiplier+
+				scoreMatch*3+int(bonusBoundaryWhite)*bonusFirstCharMultiplier+
 					bonusCamel123*2+2*scoreGapStart+2*scoreGapExtension)
 			assertMatch(t, fn, false, forward, "foo barbaz", "fbb", 0, 8,
-				scoreMatch*3+bonusBoundaryWhite*bonusFirstCharMultiplier+bonusBoundaryWhite+
+				scoreMatch*3+int(bonusBoundaryWhite)*bonusFirstCharMultiplier+int(bonusBoundaryWhite)+
 					scoreGapStart*2+scoreGapExtension*3)
 			assertMatch(t, fn, false, forward, "fooBar Baz", "foob", 0, 4,
-				scoreMatch*4+bonusBoundaryWhite*bonusFirstCharMultiplier+bonusBoundaryWhite*3)
+				scoreMatch*4+int(bonusBoundaryWhite)*bonusFirstCharMultiplier+int(bonusBoundaryWhite)*3)
 			assertMatch(t, fn, false, forward, "xFoo-Bar Baz", "foo-b", 1, 6,
 				scoreMatch*5+bonusCamel123*bonusFirstCharMultiplier+bonusCamel123*2+
 					bonusNonWord+bonusBoundary)
@@ -75,14 +75,14 @@ func TestFuzzyMatch(t *testing.T) {
 			assertMatch(t, fn, true, forward, "fooBarbaz", "oBz", 2, 9,
 				scoreMatch*3+bonusCamel123+scoreGapStart+scoreGapExtension*3)
 			assertMatch(t, fn, true, forward, "Foo/Bar/Baz", "FBB", 0, 9,
-				scoreMatch*3+bonusBoundaryWhite*bonusFirstCharMultiplier+bonusBoundaryDelimiter*2+
+				scoreMatch*3+int(bonusBoundaryWhite)*bonusFirstCharMultiplier+int(bonusBoundaryDelimiter)*2+
 					scoreGapStart*2+scoreGapExtension*4)
 			assertMatch(t, fn, true, forward, "FooBarBaz", "FBB", 0, 7,
-				scoreMatch*3+bonusBoundaryWhite*bonusFirstCharMultiplier+bonusCamel123*2+
+				scoreMatch*3+int(bonusBoundaryWhite)*bonusFirstCharMultiplier+bonusCamel123*2+
 					scoreGapStart*2+scoreGapExtension*2)
 			assertMatch(t, fn, true, forward, "FooBar Baz", "FooB", 0, 4,
-				scoreMatch*4+bonusBoundaryWhite*bonusFirstCharMultiplier+bonusBoundaryWhite*2+
-					util.Max(bonusCamel123, bonusBoundaryWhite))
+				scoreMatch*4+int(bonusBoundaryWhite)*bonusFirstCharMultiplier+int(bonusBoundaryWhite)*2+
+					util.Max(bonusCamel123, int(bonusBoundaryWhite)))
 
 			// Consecutive bonus updated
 			assertMatch(t, fn, true, forward, "foo-bar", "o-ba", 2, 6,
@@ -98,10 +98,10 @@ func TestFuzzyMatch(t *testing.T) {
 
 func TestFuzzyMatchBackward(t *testing.T) {
 	assertMatch(t, FuzzyMatchV1, false, true, "foobar fb", "fb", 0, 4,
-		scoreMatch*2+bonusBoundaryWhite*bonusFirstCharMultiplier+
+		scoreMatch*2+int(bonusBoundaryWhite)*bonusFirstCharMultiplier+
 			scoreGapStart+scoreGapExtension)
 	assertMatch(t, FuzzyMatchV1, false, false, "foobar fb", "fb", 7, 9,
-		scoreMatch*2+bonusBoundaryWhite*bonusFirstCharMultiplier+bonusBoundaryWhite)
+		scoreMatch*2+int(bonusBoundaryWhite)*bonusFirstCharMultiplier+int(bonusBoundaryWhite))
 }
 
 func TestExactMatchNaive(t *testing.T) {
@@ -114,9 +114,9 @@ func TestExactMatchNaive(t *testing.T) {
 		assertMatch(t, ExactMatchNaive, false, dir, "/AutomatorDocument.icns", "rdoc", 9, 13,
 			scoreMatch*4+bonusCamel123+bonusConsecutive*2)
 		assertMatch(t, ExactMatchNaive, false, dir, "/man1/zshcompctl.1", "zshc", 6, 10,
-			scoreMatch*4+bonusBoundaryDelimiter*(bonusFirstCharMultiplier+3))
+			scoreMatch*4+int(bonusBoundaryDelimiter)*(bonusFirstCharMultiplier+3))
 		assertMatch(t, ExactMatchNaive, false, dir, "/.oh-my-zsh/cache", "zsh/c", 8, 13,
-			scoreMatch*5+bonusBoundary*(bonusFirstCharMultiplier+3)+bonusBoundaryDelimiter)
+			scoreMatch*5+bonusBoundary*(bonusFirstCharMultiplier+3)+int(bonusBoundaryDelimiter))
 	}
 }
 
@@ -128,7 +128,7 @@ func TestExactMatchNaiveBackward(t *testing.T) {
 }
 
 func TestPrefixMatch(t *testing.T) {
-	score := scoreMatch*3 + bonusBoundaryWhite*bonusFirstCharMultiplier + bonusBoundaryWhite*2
+	score := scoreMatch*3 + int(bonusBoundaryWhite)*bonusFirstCharMultiplier + int(bonusBoundaryWhite)*2
 
 	for _, dir := range []bool{true, false} {
 		assertMatch(t, PrefixMatch, true, dir, "fooBarbaz", "Foo", -1, -1, 0)
@@ -159,7 +159,7 @@ func TestSuffixMatch(t *testing.T) {
 
 		// Only when the pattern doesn't end with a space
 		assertMatch(t, SuffixMatch, false, dir, "fooBarbaz ", "baz ", 6, 10,
-			scoreMatch*4+bonusConsecutive*2+bonusBoundaryWhite)
+			scoreMatch*4+bonusConsecutive*2+int(bonusBoundaryWhite))
 	}
 }
 
diff --git a/src/options.go b/src/options.go
index 46bda82c..41782fa4 100644
--- a/src/options.go
+++ b/src/options.go
@@ -21,9 +21,9 @@ const usage = `usage: fzf [options]
     -x, --extended        Extended-search mode
                           (enabled by default; +x or --no-extended to disable)
     -e, --exact           Enable Exact-match
-    --algo=TYPE           Fuzzy matching algorithm: [v1|v2] (default: v2)
     -i                    Case-insensitive match (default: smart-case match)
     +i                    Case-sensitive match
+    --scheme=SCHEME       Scoring scheme [default|path|history]
     --literal             Do not normalize latin script letters before matching
     -n, --nth=N[,..]      Comma-separated list of field index expressions
                           for limiting search scope. Each can be a non-zero
@@ -194,6 +194,7 @@ func (a previewOpts) sameContentLayout(b previewOpts) bool {
 type Options struct {
 	Fuzzy       bool
 	FuzzyAlgo   algo.Algo
+	Scheme      string
 	Extended    bool
 	Phony       bool
 	Case        Case
@@ -259,6 +260,7 @@ func defaultOptions() *Options {
 	return &Options{
 		Fuzzy:       true,
 		FuzzyAlgo:   algo.FuzzyMatchV2,
+		Scheme:      "default",
 		Extended:    true,
 		Phony:       false,
 		Case:        CaseSmart,
@@ -441,6 +443,15 @@ func parseAlgo(str string) algo.Algo {
 	return algo.FuzzyMatchV2
 }
 
+func processScheme(opts *Options) {
+	if !algo.Init(opts.Scheme) {
+		errorExit("invalid scoring scheme (expected: default|path|history)")
+	}
+	if opts.Scheme == "history" {
+		opts.Criteria = []criterion{byScore}
+	}
+}
+
 func parseBorder(str string, optional bool) tui.BorderShape {
 	switch str {
 	case "rounded":
@@ -1345,6 +1356,8 @@ func parseOptions(opts *Options, allArgs []string) {
 			opts.Normalize = true
 		case "--algo":
 			opts.FuzzyAlgo = parseAlgo(nextString(allArgs, &i, "algorithm required (v1|v2)"))
+		case "--scheme":
+			opts.Scheme = strings.ToLower(nextString(allArgs, &i, "scoring scheme required (default|path|history)"))
 		case "--expect":
 			for k, v := range parseKeyChords(nextString(allArgs, &i, "key names required"), "key names required") {
 				opts.Expect[k] = v
@@ -1551,6 +1564,8 @@ func parseOptions(opts *Options, allArgs []string) {
 		default:
 			if match, value := optString(arg, "--algo="); match {
 				opts.FuzzyAlgo = parseAlgo(value)
+			} else if match, value := optString(arg, "--scheme="); match {
+				opts.Scheme = strings.ToLower(value)
 			} else if match, value := optString(arg, "-q", "--query="); match {
 				opts.Query = value
 			} else if match, value := optString(arg, "-f", "--filter="); match {
@@ -1752,6 +1767,10 @@ func postProcessOptions(opts *Options) {
 		theme.Cursor = boldify(theme.Cursor)
 		theme.Spinner = boldify(theme.Spinner)
 	}
+
+	if opts.Scheme != "default" {
+		processScheme(opts)
+	}
 }
 
 func expectsArbitraryString(opt string) bool {