fuzzy

Documentation

Overview

Fuzzy searching allows for flexibly matching a string with partial input, useful for filtering data very quickly based on lightweight user input.

Index

• func Find(source string, targets []string) []string
• func FindFold(source string, targets []string) []string
• func LevenshteinDistance(s, t string) int
• func Match(source, target string) bool
• func MatchFold(source, target string) bool
• func RankMatch(source, target string) int
• func RankMatchFold(source, target string) int
• type Rank
• type Ranks
  • func RankFind(source string, targets []string) Ranks
  • func RankFindFold(source string, targets []string) Ranks
  • func (r Ranks) Len() int
  • func (r Ranks) Less(i, j int) bool
  • func (r Ranks) Swap(i, j int)

Examples

• Find
• Match
• RankFind
• RankMatch

Functions

func Find

func Find(source string, targets []string) []string

Find will return a list of strings in targets that fuzzy matches source.

Example

fmt.Print(Find("whl", []string{"cartwheel", "foobar", "wheel", "baz"}))

Output:

[cartwheel wheel]

func FindFold

func FindFold(source string, targets []string) []string

FindFold is a case-insensitive version of Find.

func LevenshteinDistance

func LevenshteinDistance(s, t string) int

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 Match

func Match(source, target string) bool

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.

Example

fmt.Print(Match("twl", "cartwheel"))

Output:

true

func MatchFold

func MatchFold(source, target string) bool

MatchFold is a case-insensitive version of Match.

func RankMatch

func RankMatch(source, target string) int

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.

Example

fmt.Print(RankMatch("twl", "cartwheel"))

Output:

6

func RankMatchFold

func RankMatchFold(source, target string) int

RankMatchFold is a case-insensitive version of RankMatch.

Types

type Rank

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
}

type Ranks

type Ranks []Rank

func RankFind

func RankFind(source string, targets []string) Ranks

RankFind is similar to Find, except it will also rank all matches using Levenshtein distance.

Example

fmt.Printf("%+v", RankFind("whl", []string{"cartwheel", "foobar", "wheel", "baz"}))

Output:

[{Source:whl Target:cartwheel Distance:6} {Source:whl Target:wheel Distance:2}]

func RankFindFold

func RankFindFold(source string, targets []string) Ranks

RankFindFold is a case-insensitive version of RankFind.

func (Ranks) Len

func (r Ranks) Len() int

func (Ranks) Less

func (r Ranks) Less(i, j int) bool

func (Ranks) Swap

func (r Ranks) Swap(i, j int)