Add fuzzysearch to vendor/

vendor/github.com/evidlo/fuzzysearch/fuzzy/fuzzy.go

@@ -0,0 +1,176 @@
+// Fuzzy searching allows for flexibly matching a string with partial input,
+// useful for filtering data very quickly based on lightweight user input.
+package fuzzy
+
+import (
+	"unicode"
+	"unicode/utf8"
+)
+
+var noop = func(r rune) rune { return r }
+
+// Match returns true if source matches target using a fuzzy-searching
+// algorithm. Note that it doesn't implement Levenshtein distance (see
+// RankMatch instead), but rather a simplified version where there's no
+// approximation. The method will return true only if each character in the
+// source can be found in the target and occurs after the preceding matches.
+func Match(source, target string) bool {
+	return match(source, target, noop)
+}
+
+// MatchFold is a case-insensitive version of Match.
+func MatchFold(source, target string) bool {
+	return match(source, target, unicode.ToLower)
+}
+
+func match(source, target string, fn func(rune) rune) bool {
+	lenDiff := len(target) - len(source)
+
+	if lenDiff < 0 {
+		return false
+	}
+
+	if lenDiff == 0 && source == target {
+		return true
+	}
+
+Outer:
+	for _, r1 := range source {
+		for i, r2 := range target {
+			if fn(r1) == fn(r2) {
+				target = target[i+utf8.RuneLen(r2):]
+				continue Outer
+			}
+		}
+		return false
+	}
+
+	return true
+}
+
+// Find will return a list of strings in targets that fuzzy matches source.
+func Find(source string, targets []string) []string {
+	return find(source, targets, noop)
+}
+
+// FindFold is a case-insensitive version of Find.
+func FindFold(source string, targets []string) []string {
+	return find(source, targets, unicode.ToLower)
+}
+
+func find(source string, targets []string, fn func(rune) rune) []string {
+	var matches []string
+
+	for _, target := range targets {
+		if match(source, target, fn) {
+			matches = append(matches, target)
+		}
+	}
+
+	return matches
+}
+
+// RankMatch is similar to Match except it will measure the Levenshtein
+// distance between the source and the target and return its result. If there
+// was no match, it will return -1.
+// Given the requirements of match, RankMatch only needs to perform a subset of
+// the Levenshtein calculation, only deletions need be considered, required
+// additions and substitutions would fail the match test.
+func RankMatch(source, target string) int {
+	return rank(source, target, noop)
+}
+
+// RankMatchFold is a case-insensitive version of RankMatch.
+func RankMatchFold(source, target string) int {
+	return rank(source, target, unicode.ToLower)
+}
+
+func rank(source, target string, fn func(rune) rune) int {
+	lenDiff := len(target) - len(source)
+
+	if lenDiff < 0 {
+		return -1
+	}
+
+	if lenDiff == 0 && source == target {
+		return 0
+	}
+
+	runeDiff := 0
+
+Outer:
+	for _, r1 := range source {
+		for i, r2 := range target {
+			if fn(r1) == fn(r2) {
+				target = target[i+utf8.RuneLen(r2):]
+				continue Outer
+			} else {
+				runeDiff++
+			}
+		}
+		return -1
+	}
+
+	// Count up remaining char
+	for len(target) > 0 {
+		target = target[utf8.RuneLen(rune(target[0])):]
+		runeDiff++
+	}
+
+	return runeDiff
+}
+
+// RankFind is similar to Find, except it will also rank all matches using
+// Levenshtein distance.
+func RankFind(source string, targets []string) Ranks {
+	var r Ranks
+
+	for index, target := range targets {
+		if match(source, target, noop) {
+			distance := LevenshteinDistance(source, target)
+			r = append(r, Rank{source, target, distance, index})
+		}
+	}
+	return r
+}
+
+// RankFindFold is a case-insensitive version of RankFind.
+func RankFindFold(source string, targets []string) Ranks {
+	var r Ranks
+
+	for index, target := range targets {
+		if match(source, target, unicode.ToLower) {
+			distance := LevenshteinDistance(source, target)
+			r = append(r, Rank{source, target, distance, index})
+		}
+	}
+	return r
+}
+
+type Rank struct {
+	// Source is used as the source for matching.
+	Source string
+
+	// Target is the word matched against.
+	Target string
+
+	// Distance is the Levenshtein distance between Source and Target.
+	Distance int
+
+	// Location of Target in original list
+	Index int
+}
+
+type Ranks []Rank
+
+func (r Ranks) Len() int {
+	return len(r)
+}
+
+func (r Ranks) Swap(i, j int) {
+	r[i], r[j] = r[j], r[i]
+}
+
+func (r Ranks) Less(i, j int) bool {
+	return r[i].Distance < r[j].Distance
+}

vendor/github.com/evidlo/fuzzysearch/fuzzy/levenshtein.go

@@ -0,0 +1,43 @@
+package fuzzy
+
+// LevenshteinDistance measures the difference between two strings.
+// The Levenshtein distance between two words is the minimum number of
+// single-character edits (i.e. insertions, deletions or substitutions)
+// required to change one word into the other.
+//
+// This implemention is optimized to use O(min(m,n)) space and is based on the
+// optimized C version found here:
+// http://en.wikibooks.org/wiki/Algorithm_implementation/Strings/Levenshtein_distance#C
+func LevenshteinDistance(s, t string) int {
+	r1, r2 := []rune(s), []rune(t)
+	column := make([]int, len(r1)+1)
+
+	for y := 1; y <= len(r1); y++ {
+		column[y] = y
+	}
+
+	for x := 1; x <= len(r2); x++ {
+		column[0] = x
+
+		for y, lastDiag := 1, x-1; y <= len(r1); y++ {
+			oldDiag := column[y]
+			cost := 0
+			if r1[y-1] != r2[x-1] {
+				cost = 1
+			}
+			column[y] = min(column[y]+1, column[y-1]+1, lastDiag+cost)
+			lastDiag = oldDiag
+		}
+	}
+
+	return column[len(r1)]
+}
+
+func min(a, b, c int) int {
+	if a < b && a < c {
+		return a
+	} else if b < c {
+		return b
+	}
+	return c
+}