list edit distances between all inputs of the same length, ascending order

editdistance

#! /usr/bin/env node

// for a JSON array of strings, or an array of lines on stdin,
// shows edit distances between all the inputs, ascending

const fs = require('fs');
const ed = require('edit-distance');

// read all strings from stdin:
let names = fs.readFileSync(0, 'utf-8');
try {
    names = JSON.parse(names);
} catch (e) {
    names = names.trim().split('\n');
}
names = uniq(names);

function uniq(arr) {
    const seen = {};
    for (const n of arr) {
        seen[n] = 1;
    }
    return Object.keys(seen);
}

function bySize(arr) {
    const sized = {};
    for (const n of arr) {
        sized[n.length] = (sized[n.length] || []).concat(n);
    }
    return sized;
}

const bysize = bySize(names);
const moreThanOne = Object.keys(bysize).filter(k => bysize[k].length > 1);
const wanted = Object.fromEntries(moreThanOne.map(k => [k, bysize[k]]));

function insert(node) { return 1; }
function remove(node) { return 1; }
function update(a, b) { return a !== b ? 1 : 0; }

const ascending = (a, b) => a[0] - b[0];

const dist = (a, b) => ed.levenshtein(a, b, insert, remove, update).distance;

const maxDist = (w, i, a) => { const d = a.slice(i + 1).map(W => dist(w, W)); return d.map((n, j) => [n, w, a[i+j+1]]); }

const byDist = (w, i, a) => {
    const d = a.slice(i + 1).map(W => dist(w, W));
    return d.map((n, j) => [n, w, a[i+j+1]]).sort(ascending);
};

const concat = (arr) => arr.reduce((a, b) => a.concat(b), []);

const allDist = (arr) => concat(arr.map(byDist)).sort(ascending);

const distances = Object.fromEntries(Object.keys(wanted).map(
    n => [n, allDist(wanted[n])]
));

const all = concat(Object.keys(distances).map(n => distances[n])).sort(ascending);

console.log(all);

package.json

{
  "name": "editdistance-cli",
  "version": "1.0.0",
  "description": "list edit distances between all inputs, ascending order",
  "main": "editdistance",
  "license": "MIT",
  "dependencies": {
    "edit-distance": "^1.0.2"
  }
}