Micro-optimizations

- Make structs smaller
- Introduce Result struct and use it to represent matched items instead of
  reusing Item struct for that purpose
- Avoid unnecessary memory allocation
- Avoid growing slice from the initial capacity
- Code cleanup

src/algo/algo.go

@@ -24,12 +24,12 @@ func indexAt(index int, max int, forward bool) int {
 
 // Result conatins the results of running a match function.
 type Result struct {
-	Start int32
-	End   int32
+	Start int
+	End   int
 
 	// Items are basically sorted by the lengths of matched substrings.
 	// But we slightly adjust the score with bonus for better results.
-	Bonus int32
+	Bonus int
 }
 
 type charClass int
@@ -42,8 +42,8 @@ const (
 	charNumber
 )
 
-func evaluateBonus(caseSensitive bool, text util.Chars, pattern []rune, sidx int, eidx int) int32 {
-	var bonus int32
+func evaluateBonus(caseSensitive bool, text util.Chars, pattern []rune, sidx int, eidx int) int {
+	var bonus int
 	pidx := 0
 	lenPattern := len(pattern)
 	consecutive := false
@@ -63,7 +63,7 @@ func evaluateBonus(caseSensitive bool, text util.Chars, pattern []rune, sidx int
 			class = charNonWord
 		}
 
-		var point int32
+		var point int
 		if prevClass == charNonWord && class != charNonWord {
 			// Word boundary
 			point = 2
@@ -181,7 +181,7 @@ func FuzzyMatch(caseSensitive bool, forward bool, text util.Chars, pattern []run
 			sidx, eidx = lenRunes-eidx, lenRunes-sidx
 		}
 
-		return Result{int32(sidx), int32(eidx),
+		return Result{sidx, eidx,
 			evaluateBonus(caseSensitive, text, pattern, sidx, eidx)}
 	}
 	return Result{-1, -1, 0}
@@ -228,7 +228,7 @@ func ExactMatchNaive(caseSensitive bool, forward bool, text util.Chars, pattern
 					sidx = lenRunes - (index + 1)
 					eidx = lenRunes - (index - lenPattern + 1)
 				}
-				return Result{int32(sidx), int32(eidx),
+				return Result{sidx, eidx,
 					evaluateBonus(caseSensitive, text, pattern, sidx, eidx)}
 			}
 		} else {
@@ -255,7 +255,7 @@ func PrefixMatch(caseSensitive bool, forward bool, text util.Chars, pattern []ru
 		}
 	}
 	lenPattern := len(pattern)
-	return Result{0, int32(lenPattern),
+	return Result{0, lenPattern,
 		evaluateBonus(caseSensitive, text, pattern, 0, lenPattern)}
 }
 
@@ -279,7 +279,7 @@ func SuffixMatch(caseSensitive bool, forward bool, text util.Chars, pattern []ru
 	lenPattern := len(pattern)
 	sidx := trimmedLen - lenPattern
 	eidx := trimmedLen
-	return Result{int32(sidx), int32(eidx),
+	return Result{sidx, eidx,
 		evaluateBonus(caseSensitive, text, pattern, sidx, eidx)}
 }
 
@@ -294,7 +294,7 @@ func EqualMatch(caseSensitive bool, forward bool, text util.Chars, pattern []run
 		runesStr = strings.ToLower(runesStr)
 	}
 	if runesStr == string(pattern) {
-		return Result{0, int32(len(pattern)), 0}
+		return Result{0, len(pattern), 0}
 	}
 	return Result{-1, -1, 0}
 }

src/algo/algo_test.go

@@ -7,7 +7,7 @@ import (
 	"github.com/junegunn/fzf/src/util"
 )
 
-func assertMatch(t *testing.T, fun func(bool, bool, util.Chars, []rune) Result, caseSensitive, forward bool, input, pattern string, sidx int32, eidx int32, bonus int32) {
+func assertMatch(t *testing.T, fun func(bool, bool, util.Chars, []rune) Result, caseSensitive, forward bool, input, pattern string, sidx int, eidx int, bonus int) {
 	if !caseSensitive {
 		pattern = strings.ToLower(pattern)
 	}