Add bip39 suggestions (#238)

* fix(): add bip39 and wordlist selection
* fix(): fix undefined as suggestion
* fix(): simplify as much as possible and only suggest the latest word
* feat: Binary search, stateless word list selection
* feat: allow duplicates in suggestions
* fix(): show suggestions even if input is uppercase

res/bip39_wordlist.json

+["abandon","ability","able","about","above","absent","absorb","abstract","absurd","abuse","access","accident","account","accuse","achieve","acid","acoustic","acquire","across","act","action","actor","actress","actual","adapt","add","addict","address","adjust","admit","adult","advance","advice","aerobic","affair","afford","afraid","again","age","agent","agree","ahead","aim","air","airport","aisle","alarm","album","alcohol","alert","alien","all","alley","allow","almost","alone","alpha","already","also","alter","always","amateur","amazing","among","amount","amused","analyst","anchor","ancient","anger","angle","angry","animal","ankle","announce","annual","another","answer","antenna","antique","anxiety","any","apart","apology","appear","apple","approve","april","arch","arctic","area","arena","argue","arm","armed","armor","army","around","arrange","arrest","arrive","arrow","art","artefact","artist","artwork","ask","aspect","assault","asset","assist","assume","asthma","athlete","atom","attack","attend","attitude","attract","auction","audit","august","aunt","author","auto","autumn","average","avocado","avoid","awake","aware","away","awesome","awful","awkward","axis","baby","bachelor","bacon","badge","bag","balance","balcony","ball","bamboo","banana","banner","bar","barely","bargain","barrel","base","basic","basket","battle","beach","bean","beauty","because","become","beef","before","begin","behave","behind","believe","below","belt","bench","benefit","best","betray","better","between","beyond","bicycle","bid","bike","bind","biology","bird","birth","bitter","black","blade","blame","blanket","blast","bleak","bless","blind","blood","blossom","blouse","blue","blur","blush","board","boat","body","boil","bomb","bone","bonus","book","boost","border","boring","borrow","boss","bottom","bounce","box","boy","bracket","brain","brand","brass","brave","bread","breeze","brick","bridge","brief","bright","bring","brisk","broccoli","broken","bronze","broom","brother","brown","brush","bubble","buddy","budget","buffalo","build","bulb","bulk","bullet","bundle","bunker","burden","burger","burst","bus","business","busy","butter","buyer","buzz","cabbage","cabin","cable","cactus","cage","cake","call","calm","camera","camp","can","canal","cancel","candy","cannon","canoe","canvas","canyon","capable","capital","captain","car","carbon","card","cargo","carpet","carry","cart","case","cash","casino","castle","casual","cat","catalog","catch","category","cattle","caught","cause","caution","cave","ceiling","celery","cement","census","century","cereal","certain","chair","chalk","champion","change","chaos","chapter","charge","chase","chat","cheap","check","cheese","chef","cherry","chest","chicken","chief","child","chimney","choice","choose","chronic","chuckle","chunk","churn","cigar","cinnamon","circle","citizen","city","civil","claim","clap","clarify","claw","clay","clean","clerk","clever","click","client","cliff","climb","clinic","clip","clock","clog","close","cloth","cloud","clown","club","clump","cluster","clutch","coach","coast","coconut","code","coffee","coil","coin","collect","color","column","combine","come","comfort","comic","common","company","concert","conduct","confirm","congress","connect","consider","control","convince","cook","cool","copper","copy","coral","core","corn","correct","cost","cotton","couch","country","couple","course","cousin","cover","coyote","crack","cradle","craft","cram","crane","crash","crater","crawl","crazy","cream","credit","creek","crew","cricket","crime","crisp","critic","crop","cross","crouch","crowd","crucial","cruel","cruise","crumble","crunch","crush","cry","crystal","cube","culture","cup","cupboard","curious","current","curtain","curve","cushion","custom","cute","cycle","dad","damage","damp","dance","danger","daring","dash","daughter","dawn","day","deal","debate","debris","decade","december","decide","decline","decorate","decrease","deer","defense","define","defy","degree","delay","deliver","demand","demise","denial","dentist","deny","depart","depend","deposit","depth","deputy","derive","describe","desert","design","desk","despair","destroy","detail","detect","develop","device","devote","diagram","dial","diamond","diary","dice","diesel","diet","differ","digital","dignity","dilemma","dinner","dinosaur","direct","dirt","disagree","discover","disease","dish","dismiss","disorder","display","distance","divert","divide","divorce","dizzy","doctor","document","dog","doll","dolphin","domain","donate","donkey","donor","door","dose","double","dove","draft","dragon","drama","drastic","draw","dream","dress","drift","drill","drink","drip","drive","drop","drum","dry","duck","dumb","dune","during","dust","dutch","duty","dwarf","dynamic","eager","eagle","early","earn","earth","easily","east","easy","echo","ecology","economy","edge","edit","educate","effort","egg","eight","either","elbow","elder","electric","elegant","element","elephant","elevator","elite","else","embark","embody","embrace","emerge","emotion","employ","empower","empty","enable","enact","end","endless","endorse","enemy","energy","enforce","engage","engine","enhance","enjoy","enlist","enough","enrich","enroll","ensure","enter","entire","entry","envelope","episode","equal","equip","era","erase","erode","erosion","error","erupt","escape","essay","essence","estate","eternal","ethics","evidence","evil","evoke","evolve","exact","example","excess","exchange","excite","exclude","excuse","execute","exercise","exhaust","exhibit","exile","exist","exit","exotic","expand","expect","expire","explain","expose","express","extend","extra","eye","eyebrow","fabric","face","faculty","fade","faint","faith","fall","false","fame","family","famous","fan","fancy","fantasy","farm","fashion","fat","fatal","father","fatigue","fault","favorite","feature","february","federal","fee","feed","feel","female","fence","festival","fetch","fever","few","fiber","fiction","field","figure","file","film","filter","final","find","fine","finger","finish","fire","firm","first","fiscal","fish","fit","fitness","fix","flag","flame","flash","flat","flavor","flee","flight","flip","float","flock","floor","flower","fluid","flush","fly","foam","focus","fog","foil","fold","follow","food","foot","force","forest","forget","fork","fortune","forum","forward","fossil","foster","found","fox","fragile","frame","frequent","fresh","friend","fringe","frog","front","frost","frown","frozen","fruit","fuel","fun","funny","furnace","fury","future","gadget","gain","galaxy","gallery","game","gap","garage","garbage","garden","garlic","garment","gas","gasp","gate","gather","gauge","gaze","general","genius","genre","gentle","genuine","gesture","ghost","giant","gift","giggle","ginger","giraffe","girl","give","glad","glance","glare","glass","glide","glimpse","globe","gloom","glory","glove","glow","glue","goat","goddess","gold","good","goose","gorilla","gospel","gossip","govern","gown","grab","grace","grain","grant","grape","grass","gravity","great","green","grid","grief","grit","grocery","group","grow","grunt","guard","guess","guide","guilt","guitar","gun","gym","habit","hair","half","hammer","hamster","hand","happy","harbor","hard","harsh","harvest","hat","have","hawk","hazard","head","health","heart","heavy","hedgehog","height","hello","helmet","help","hen","hero","hidden","high","hill","hint","hip","hire","history","hobby","hockey","hold","hole","holiday","hollow","home","honey","hood","hope","horn","horror","horse","hospital","host","hotel","hour","hover","hub","huge","human","humble","humor","hundred","hungry","hunt","hurdle","hurry","hurt","husband","hybrid","ice","icon","idea","identify","idle","ignore","ill","illegal","illness","image","imitate","immense","immune","impact","impose","improve","impulse","inch","include","income","increase","index","indicate","indoor","industry","infant","inflict","inform","inhale","inherit","initial","inject","injury","inmate","inner","innocent","input","inquiry","insane","insect","inside","inspire","install","intact","interest","into","invest","invite","involve","iron","island","isolate","issue","item","ivory","jacket","jaguar","jar","jazz","jealous","jeans","jelly","jewel","job","join","joke","journey","joy","judge","juice","jump","jungle","junior","junk","just","kangaroo","keen","keep","ketchup","key","kick","kid","kidney","kind","kingdom","kiss","kit","kitchen","kite","kitten","kiwi","knee","knife","knock","know","lab","label","labor","ladder","lady","lake","lamp","language","laptop","large","later","latin","laugh","laundry","lava","law","lawn","lawsuit","layer","lazy","leader","leaf","learn","leave","lecture","left","leg","legal","legend","leisure","lemon","lend","length","lens","leopard","lesson","letter","level","liar","liberty","library","license","life","lift","light","like","limb","limit","link","lion","liquid","list","little","live","lizard","load","loan","lobster","local","lock","logic","lonely","long","loop","lottery","loud","lounge","love","loyal","lucky","luggage","lumber","lunar","lunch","luxury","lyrics","machine","mad","magic","magnet","maid","mail","main","major","make","mammal","man","manage","mandate","mango","mansion","manual","maple","marble","march","margin","marine","market","marriage","mask","mass","master","match","material","math","matrix","matter","maximum","maze","meadow","mean","measure","meat","mechanic","medal","media","melody","melt","member","memory","mention","menu","mercy","merge","merit","merry","mesh","message","metal","method","middle","midnight","milk","million","mimic","mind","minimum","minor","minute","miracle","mirror","misery","miss","mistake","mix","mixed","mixture","mobile","model","modify","mom","moment","monitor","monkey","monster","month","moon","moral","more","morning","mosquito","mother","motion","motor","mountain","mouse","move","movie","much","muffin","mule","multiply","muscle","museum","mushroom","music","must","mutual","myself","mystery","myth","naive","name","napkin","narrow","nasty","nation","nature","near","neck","need","negative","neglect","neither","nephew","nerve","nest","net","network","neutral","never","news","next","nice","night","noble","noise","nominee","noodle","normal","north","nose","notable","note","nothing","notice","novel","now","nuclear","number","nurse","nut","oak","obey","object","oblige","obscure","observe","obtain","obvious","occur","ocean","october","odor","off","offer","office","often","oil","okay","old","olive","olympic","omit","once","one","onion","online","only","open","opera","opinion","oppose","option","orange","orbit","orchard","order","ordinary","organ","orient","original","orphan","ostrich","other","outdoor","outer","output","outside","oval","oven","over","own","owner","oxygen","oyster","ozone","pact","paddle","page","pair","palace","palm","panda","panel","panic","panther","paper","parade","parent","park","parrot","party","pass","patch","path","patient","patrol","pattern","pause","pave","payment","peace","peanut","pear","peasant","pelican","pen","penalty","pencil","people","pepper","perfect","permit","person","pet","phone","photo","phrase","physical","piano","picnic","picture","piece","pig","pigeon","pill","pilot","pink","pioneer","pipe","pistol","pitch","pizza","place","planet","plastic","plate","play","please","pledge","pluck","plug","plunge","poem","poet","point","polar","pole","police","pond","pony","pool","popular","portion","position","possible","post","potato","pottery","poverty","powder","power","practice","praise","predict","prefer","prepare","present","pretty","prevent","price","pride","primary","print","priority","prison","private","prize","problem","process","produce","profit","program","project","promote","proof","property","prosper","protect","proud","provide","public","pudding","pull","pulp","pulse","pumpkin","punch","pupil","puppy","purchase","purity","purpose","purse","push","put","puzzle","pyramid","quality","quantum","quarter","question","quick","quit","quiz","quote","rabbit","raccoon","race","rack","radar","radio","rail","rain","raise","rally","ramp","ranch","random","range","rapid","rare","rate","rather","raven","raw","razor","ready","real","reason","rebel","rebuild","recall","receive","recipe","record","recycle","reduce","reflect","reform","refuse","region","regret","regular","reject","relax","release","relief","rely","remain","remember","remind","remove","render","renew","rent","reopen","repair","repeat","replace","report","require","rescue","resemble","resist","resource","response","result","retire","retreat","return","reunion","reveal","review","reward","rhythm","rib","ribbon","rice","rich","ride","ridge","rifle","right","rigid","ring","riot","ripple","risk","ritual","rival","river","road","roast","robot","robust","rocket","romance","roof","rookie","room","rose","rotate","rough","round","route","royal","rubber","rude","rug","rule","run","runway","rural","sad","saddle","sadness","safe","sail","salad","salmon","salon","salt","salute","same","sample","sand","satisfy","satoshi","sauce","sausage","save","say","scale","scan","scare","scatter","scene","scheme","school","science","scissors","scorpion","scout","scrap","screen","script","scrub","sea","search","season","seat","second","secret","section","security","seed","seek","segment","select","sell","seminar","senior","sense","sentence","series","service","session","settle","setup","seven","shadow","shaft","shallow","share","shed","shell","sheriff","shield","shift","shine","ship","shiver","shock","shoe","shoot","shop","short","shoulder","shove","shrimp","shrug","shuffle","shy","sibling","sick","side","siege","sight","sign","silent","silk","silly","silver","similar","simple","since","sing","siren","sister","situate","six","size","skate","sketch","ski","skill","skin","skirt","skull","slab","slam","sleep","slender","slice","slide","slight","slim","slogan","slot","slow","slush","small","smart","smile","smoke","smooth","snack","snake","snap","sniff","snow","soap","soccer","social","sock","soda","soft","solar","soldier","solid","solution","solve","someone","song","soon","sorry","sort","soul","sound","soup","source","south","space","spare","spatial","spawn","speak","special","speed","spell","spend","sphere","spice","spider","spike","spin","spirit","split","spoil","sponsor","spoon","sport","spot","spray","spread","spring","spy","square","squeeze","squirrel","stable","stadium","staff","stage","stairs","stamp","stand","start","state","stay","steak","steel","stem","step","stereo","stick","still","sting","stock","stomach","stone","stool","story","stove","strategy","street","strike","strong","struggle","student","stuff","stumble","style","subject","submit","subway","success","such","sudden","suffer","sugar","suggest","suit","summer","sun","sunny","sunset","super","supply","supreme","sure","surface","surge","surprise","surround","survey","suspect","sustain","swallow","swamp","swap","swarm","swear","sweet","swift","swim","swing","switch","sword","symbol","symptom","syrup","system","table","tackle","tag","tail","talent","talk","tank","tape","target","task","taste","tattoo","taxi","teach","team","tell","ten","tenant","tennis","tent","term","test","text","thank","that","theme","then","theory","there","they","thing","this","thought","three","thrive","throw","thumb","thunder","ticket","tide","tiger","tilt","timber","time","tiny","tip","tired","tissue","title","toast","tobacco","today","toddler","toe","together","toilet","token","tomato","tomorrow","tone","tongue","tonight","tool","tooth","top","topic","topple","torch","tornado","tortoise","toss","total","tourist","toward","tower","town","toy","track","trade","traffic","tragic","train","transfer","trap","trash","travel","tray","treat","tree","trend","trial","tribe","trick","trigger","trim","trip","trophy","trouble","truck","true","truly","trumpet","trust","truth","try","tube","tuition","tumble","tuna","tunnel","turkey","turn","turtle","twelve","twenty","twice","twin","twist","two","type","typical","ugly","umbrella","unable","unaware","uncle","uncover","under","undo","unfair","unfold","unhappy","uniform","unique","unit","universe","unknown","unlock","until","unusual","unveil","update","upgrade","uphold","upon","upper","upset","urban","urge","usage","use","used","useful","useless","usual","utility","vacant","vacuum","vague","valid","valley","valve","van","vanish","vapor","various","vast","vault","vehicle","velvet","vendor","venture","venue","verb","verify","version","very","vessel","veteran","viable","vibrant","vicious","victory","video","view","village","vintage","violin","virtual","virus","visa","visit","visual","vital","vivid","vocal","voice","void","volcano","volume","vote","voyage","wage","wagon","wait","walk","wall","walnut","want","warfare","warm","warrior","wash","wasp","waste","water","wave","way","wealth","weapon","wear","weasel","weather","web","wedding","weekend","weird","welcome","west","wet","whale","what","wheat","wheel","when","where","whip","whisper","wide","width","wife","wild","will","win","window","wine","wing","wink","winner","winter","wire","wisdom","wise","wish","witness","wolf","woman","wonder","wood","wool","word","work","world","worry","worth","wrap","wreck","wrestle","wrist","write","wrong","yard","year","yellow","you","young","youth","zebra","zero","zone","zoo"]
\ No newline at end of file

rust/signer/Cargo.lock

+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
 [[package]]
 name = "adler32"
 version = "1.0.3"

src/components/AccountSeed.js

@@ -17,154 +17,100 @@
 'use strict';
 
 import React, { Component } from 'react';
-import { Animated, StyleSheet, Text, View } from 'react-native';
+import { StyleSheet, Text, View } from 'react-native';
 import colors from '../colors';
-import { WORDS, WORDS_INDEX } from '../util/account';
+import PARITY_WORDS from '../../res/parity_wordlist.json';
+import BIP39_WORDS from '../../res/bip39_wordlist.json';;
 import TextInput from './TextInput';
 import TouchableItem from './TouchableItem';
+import { binarySearch } from '../util/array';
+
+// Combined, de-duplicated, sorted word list (could be a precompute from json as well)
+const ALL_WORDS = Array.from(new Set(PARITY_WORDS.concat(BIP39_WORDS))).sort();
+const SUGGESTIONS_COUNT = 5;
 
 export default class AccountSeed extends Component {
   state = {
     cursorPosition: 0,
-    keyboard: false,
-    animation: false,
-    suggestionsHeight: new Animated.Value(0) // Initial value for opacity: 0
   };
 
-  constructor(...args) {
-    super(...args);
-    this.getSuggestions = this.getSuggestions.bind(this);
-    this.handleCursorPosition = this.handleCursorPosition.bind(this);
-    this.getWordPosition = this.getWordPosition.bind(this);
-    this.keyboardDidShow = this.keyboardDidShow.bind(this);
-    this.keyboardDidHide = this.keyboardDidHide.bind(this);
-  }
-
-  keyboardDidShow() {
-    this.setState({ keyboard: true, animation: true });
-    Animated.timing(
-      // Animate over time
-      this.state.suggestionsHeight, // The animated value to drive
-      {
-        toValue: 35, // Animate to opacity: 1 (opaque)
-        duration: 200 // Make it take a while
-      }
-    ).start(() => this.setState({ animation: false }));
-  }
+  handleCursorPosition = (event) => {
+    const {start, end} = event.nativeEvent.selection;
 
-  keyboardDidHide() {
-    this.setState({ animation: true });
-    Animated.timing(
-      // Animate over time
-      this.state.suggestionsHeight, // The animated value to drive
-      {
-        toValue: 0, // Animate to opacity: 1 (opaque)
-        duration: 200 // Make it take a while
-      }
-    ).start(() => {
-      this.setState({ keyboard: false, animation: false });
-    });
-  }
-
-  handleCursorPosition({
-    nativeEvent: {
-      selection: { start, end }
-    }
-  }) {
     if (start !== end) {
       return;
     }
     this.setState({ cursorPosition: start });
   }
 
-  getSearchInput() {
-    const { value } = this.props;
-    const { cursorPosition } = this.state;
-    let startFrom = cursorPosition;
-    // find the first space or start of string
-    while (startFrom > 0 && [' '].indexOf(value.charAt(startFrom - 1)) === -1) {
-      --startFrom;
-    }
-    return value.substring(startFrom, cursorPosition);
-  }
+  /**
+   * Generate a list of suggestions for input
+   *
+   * @param {string}   input    to find suggestions for
+   * @param {string[]} wordList to find suggestions in
+   *
+   * @return {string[]} suggestions
+   */
+  generateSuggestions (input, wordList) {
+    const fromIndex = binarySearch(wordList, input).index; // index to start search from
 
-  getWordPosition() {
-    const { value } = this.props;
-    const { cursorPosition } = this.state;
-    let wordPosition = 0;
-    let cursor = 0;
-    let char = '';
-    let wasLetter = false;
-    if (0 === value.length) {
-      return 0;
-    }
-    while (true) {
-      if (cursorPosition === cursor || (char = value.charAt(cursor)) === '') {
-        break;
-      }
-      if ([' ', '\n', '\r'].indexOf(char) === -1) {
-        wasLetter = true;
-      } else {
-        if (wasLetter) {
-          ++wordPosition;
-        }
-        wasLetter = false;
-      }
-      ++cursor;
+    let suggestions = wordList.slice(fromIndex, fromIndex + SUGGESTIONS_COUNT);
+
+    const lastValidIndex = suggestions.findIndex((word) => !word.startsWith(input));
+
+    if (lastValidIndex !== -1) {
+      suggestions = suggestions.slice(0, lastValidIndex);
     }
-    return wordPosition;
+
+    return suggestions;
   }
 
-  getSuggestions(input, words) {
-    let fromIndex = WORDS.findIndex(w => w.startsWith(input));
-    if (fromIndex === -1) {
-      return [];
-    }
-    if (WORDS[fromIndex] === input) {
-      fromIndex = 0;
-    }
-    const SUGGESTIONS_COUNT = 5;
-    const result = [];
-    let yielded = 0;
-    result.push(WORDS[fromIndex]);
-    while (yielded < SUGGESTIONS_COUNT && WORDS[fromIndex] !== undefined) {
-      ++fromIndex;
-      if (!WORDS[fromIndex].startsWith(input)) {
-        return result;
-      }
-      if (words.indexOf(WORDS[fromIndex]) !== -1) {
-        continue;
+  selectWordList (otherWords) {
+    for (const word of otherWords) {
+      const isBIP39 = binarySearch(BIP39_WORDS, word).hit;
+      const isParity = binarySearch(PARITY_WORDS, word).hit;
+
+      if (!isBIP39 && isParity) {
+        return PARITY_WORDS;
+      } else if (isBIP39 && !isParity) {
+        return BIP39_WORDS;
       }
-      result.push(WORDS[fromIndex]);
-      ++yielded;
     }
-    return result;
+
+    return ALL_WORDS;
   }
 
-  renderSuggestions() {
+  renderSuggestions () {
     const { value } = this.props;
-    const words = value.length ? value.split(' ') : [];
-    const wordPosition = this.getWordPosition();
-    let searchInput = this.getSearchInput();
-    if (WORDS_INDEX[searchInput]) {
-      searchInput = '';
-    }
-    const suggestions = this.getSuggestions(searchInput, words);
+    const { cursorPosition } = this.state;
+
+    let left = value.substring(0, cursorPosition).split(' ');
+    let right = value.substring(cursorPosition).split(' ');
+
+    // combine last nibble before cursor and first nibble after cursor into a word
+    const input = left[left.length - 1] + right[0];
+
+    left = left.slice(0, -1);
+    right = right.slice(1);
+
+    // find a wordList using words around as discriminator
+    const wordList = this.selectWordList(left.concat(right));
+    const suggestions = this.generateSuggestions(input.toLowerCase(), wordList);
+
     return (
-      <Animated.View
-        style={[styles.suggestions, { height: this.state.suggestionsHeight }]}
-      >
+      <View style={styles.suggestions}>
         {suggestions.map((suggestion, i) => {
           const sepStyle =
-            !this.state.animation && i !== suggestions.length - 1
+            i !== suggestions.length - 1
               ? { borderRightWidth: 0.3, borderColor: colors.card_bg_text_sec }
               : {};
           return (
             <TouchableItem
               key={i}
               onPress={e => {
-                words[wordPosition] = suggestion;
-                this.props.onChangeText(words.join(' '));
+                const phrase = left.concat(suggestion, right).join(' ');
+
+                this.props.onChangeText(phrase);
               }}
             >
               <View key={suggestion} style={[styles.suggestion, sepStyle]}>
@@ -173,13 +119,12 @@ export default class AccountSeed extends Component {
             </TouchableItem>
           );
         })}
-      </Animated.View>
+      </View>
     );
   }
 
-  render() {
-    const { keyboard } = this.state;
-    const { valid } = this.props;
+  render () {
+    const { valid, value } = this.props;
     const invalidStyles = !valid ? styles.invalidInput : {};
     return (
       <View>
@@ -187,15 +132,10 @@ export default class AccountSeed extends Component {
           style={[styles.input, invalidStyles]}
           multiline
           autoCapitalize="none"
-          onBlur={this.keyboardDidHide}
           onSelectionChange={this.handleCursorPosition}
           {...this.props}
-          onFocus={(...args) => {
-            this.keyboardDidShow();
-            return this.props.onFocus(...args);
-          }}
         />
-        {keyboard && this.renderSuggestions()}
+        {value.length > 0 && this.renderSuggestions()}
       </View>
     );
   }
@@ -221,7 +161,7 @@ const styles = StyleSheet.create({
     paddingHorizontal: 5,
     height: 35,
     flexDirection: 'row',
-    alignItems: 'center'
+    alignItems: 'center',
   },
   suggestion: {
     paddingVertical: 9,

src/screens/AccountRecover.js

@@ -36,7 +36,7 @@ export default class AccountRecover extends React.Component {
     title: 'Recover Account',
     headerBackTitle: 'Back'
   };
-  render() {
+  render () {
     return (
       <Subscribe to={[AccountsStore]}>
         {accounts => <AccountRecoverView {...this.props} accounts={accounts} />}
@@ -50,7 +50,7 @@ class AccountRecoverView extends React.Component {
     super(...args);
   }
 
-  render() {
+  render () {
     const { accounts } = this.props;
     const selected = accounts.getNew();
     const chainId = selected.chainId;

src/util/account.js

-import WORDS from '../../res/wordlist.json';
 import { NETWORK_ID, NETWORK_TYPE } from '../constants';
 
-export { WORDS };
-export const WORDS_INDEX = WORDS.reduce(
-  (res, w) => Object.assign(res, { [w]: 1 }),
-  {}
-);
-
-export function accountId({
+export function accountId ({
   address,
   networkType = 'ethereum',
   chainId = '1'
@@ -18,7 +11,7 @@ export function accountId({
   return `${networkType}:0x${address.toLowerCase()}@${chainId}`;
 }
 
-export function empty(account = {}) {
+export function empty (account = {}) {
   return {
     name: '',
     networkType: NETWORK_TYPE.ethereum,
@@ -34,7 +27,7 @@ export function empty(account = {}) {
   };
 }
 
-export function validateSeed(seed) {
+export function validateSeed (seed) {
   if (seed.length === 0) {
     return {
       valid: false,

src/util/array.js

+/**
+ * Default comparator, should work for strings and numbers
+ */
+function defaultCompare(a, b) {
+  if (a > b) {
+      return 1;
+  }
+
+  if (a < b) {
+      return -1;
+  }
+
+  return 0;
+}
+
+/**
+ * Find an index of an element within a sorted array. This should be substantially
+ * faster than `indexOf` for large arrays.
+ *
+ * @type  {T}                item    type
+ * @param {T}                item    to find
+ * @param {Array<T>}         array   to look through
+ * @param {(a, b) => number} [compare = defaultCompare] comparator function
+ *
+ * @return {{ hit: bool, index: number }} if `hit` is `true` -> index at which the item was found
+ *                                        if `hit` is `false` -> index at which the item can be inserted
+ */
+export function binarySearch(array, item, compare = defaultCompare) {
+  if (array.length === 0) {
+    return { hit: false, index: 0 };
+  }
+
+  let min = 0;
+  let max = array.length - 1;
+
+  while (min <= max) {
+    let guess = (min + max) >> 1; // fast integer division by 2
+
+    const result = compare(item, array[guess]);
+
+    if (result < 0) {
+      max = guess - 1;
+    } else if (result > 0) {
+      min = guess + 1;
+    } else {
+      return { hit: true, index: guess };
+    }
+  }
+
+  return { hit: false, index: min };
+}