node-fzy

Node.js binding to the original C fzy.

Install

Requires a compiler.

npm install node-fzy

API

// Returns if there is a match
function fzy.hasMatch(needle: String, haystack: String|String[]): Boolean;
// Returns the score
function fzy.match(needle: String, haystack: String|String[]): Number;
// Returns the score and positions
function fzy.matchPositions(needle: String, haystack: String|String[]): [Number, Number[]];

// Returns if there is a match
function fzy.hasMatchMulti(needle: String, haystack: String[]): Boolean;
// Returns the score
function fzy.matchMulti(needle: String, haystack: String[]): Number;
// Returns the score and positions
function fzy.matchPositionsMulti(needle: String, haystack: String[]): [Number, Number[]];

The *Multi variants run the loop over haystacks in C, as opposed to the non-*Multi that run the loop over haystacks in javascript.

The non-*Multi variants accepts either one haystack or a list of haystacks.

The benchmarks in terms of performance for looping in javascript or in C are inconclusive. Below is one example but do not take that to mean anything, sometimes the javascript is faster consistently, other times it switches

method	Searching for 'f' in 85k entries
loop-js	138.214ms
loop-c	131.86ms

Speed

To increase speed when searching for results, here are 2 things you can do:

When you're ranking matches, dont score all of them! You need to eliminate bad matches with fzy.hasMatch first. Those who pass may be scored.
When you're search query is simply the previous query plus some new character, don't search again on the whole set. Cache the last set of matches for the previous query and re-use that subset to do the current search.

Note

.matchPositions* returns the score and the positions. The positions are invalid if it doesn't match, which can be verified previously with .hasMatch or by checking if the score is -Infinity.

Example

const fzy = require('..')

const files = [
  'binding.gyp',
  'build/Debug/node_fzy.node',
  'build/Debug/obj.target/action_after_build.stamp',
  'build/Debug/obj.target/node_fzy/src/main.o',
  'build/Debug/obj.target/node_fzy.node',
  'build/Makefile',
  'build/Release/module.node',
  'build/Release/obj.target/module/src/main.o',
  'build/Release/obj.target/module.node',
  'build/action_after_build.target.mk',
  'build/binding.Makefile',
  'build/config.gypi',
  'build/module.target.mk',
  'build/node_fzy.target.mk',
  'compile_commands.json',
  'lib/binding/node-v83-linux-x64/node_fzy.node',
  'lib/index.js',
  'lib/native.js',
  'package-lock.json',
  'package.json',
  'src/main.cc',
]

const results = fzy.matchPositions('umo', files)

results.forEach(([score, positions], i) => {
  console.log([score, files[i], positions])
})

Differences with the original fzy

If the needle contains uppercase letters, the search is case-sensitive
Perfect matches are returned with the highest score