使用功能性javascript和ramda查找和替换

Question

I am looking into ramda and have t questions, from the following Ramda REPL :

const R = require('ramda')
//const original = require('./test/fixtures/original.json')
const original = {
  speakers: {
    name: 'Author',
    words: [
      { duration: '0.360000', name: 'Arthur', time: '0.660000',   paragraph: 'p0-0' },
      { duration: '0.150000', name: 'the',    time: '1.020000',   paragraph: 'p0-0' },
      { duration: '0.380000', name: 'rat',    time: '1.170000',   paragraph: 'p0-0' },
      { duration: '0.770000', name: '.',      time: '1.550000',   paragraph: 'p0-0' },
      { duration: '0.360000', name: 'Arthur', time: '89.820000',  paragraph: 'p1-0' },
      { duration: '0.390000', name: 'stood',  time: '90.180000',  paragraph: 'p1-0' },
      { duration: '0.090000', name: 'and',    time: '90.570000',  paragraph: 'p1-0' }
    ]
  }
}

const words = R.lensPath(['speakers', 'words'])
const wordsList = R.view(words, original)
const result = [...wordsList.reduce((hash, { duration, time, name, paragraph }) => {
  const current = hash.get(paragraph) || { paragraph, words: [] };

  current.words.push({ duration, time, name });

  return hash.set(paragraph, current);
}, new Map).values()];

console.log(result);

How do I use groupBy in order to get it grouped by paragraphs instead of the above method?

From this result, how do I do a find of a string that can have one or more items, by sorting all the words in order of time and returning only the matched paragraphs?

search_criteria = 'Arthur stood';

results = [ 
  { para: 'p1-0', 
    words: [
      { 'name': 'Arthur', 'time': 89.820000},
      { 'name': 'stood', 'time': 90.180000}
  }
]

How would you replace these items with replace = 'Arthuro stopped' ?

Any advise is much appreciated.

Answer 1

One way to solve your first problem with Ramda would be like this:

pipe(
  view(lensPath(['speakers', 'words'])),  // original.speakers.words (null-safe)
  groupBy(prop('paragraph')),             // object with keys of para name, values of list of matching records
  map(map(dissoc('paragraph'))),          // removing unneeded para from records
  toPairs,                                // {p1: [...words1], p2: [...words2]} => [[p1, [...words1]], [p2, [...words2]]] 
  map(zipObj(['paragraph', 'words']))     // expected output structure
)(original)

You asked specifically about groupBy . After the groupBy(prop('paragraph')) clause, the data looks like this:

{
  "p0-0": [
    {duration: "0.360000", name: "Arthur", paragraph: "p0-0", time: "0.660000"},
    {duration: "0.150000", name: "the", paragraph: "p0-0", time: "1.020000"},
    {duration: "0.380000", name: "rat", paragraph: "p0-0", time: "1.170000"},
    {duration: "0.770000", name: ".", paragraph: "p0-0", time: "1.550000"}
  ],
  "p1-0": [
    {duration: "0.360000", name: "Arthur", paragraph: "p1-0", time: "89.820000"},
    {duration: "0.390000", name: "stood", paragraph: "p1-0", time: "90.180000"},
    {duration: "0.090000", name: "and", paragraph: "p1-0", time: "90.570000"}
  ]
}

The remainder is just fiddling to get the output structure you're looking for.

You can see the results in the Ramda REPL . (If you comment out later lines in the pipe, you can see any intermediate results.)

For the second half of your question, I'd suggest you open a new topic, demonstrating what you've attempted so far.