Перенести JavaScript асинхронный и код igraph на R?

Question

Я изо всех сил пытаюсь перенести некоторый код JavaScript (который включает в себя функции асинхронности и графики) на R. Помогите, пожалуйста!

Вот что я пытаюсь портировать:

import jsonpFetch from"./jsonpFetch";импорт шины из '../bus';

/**
 * This function builds a graph from google's auto-suggestions.
 */
export default function buildGraph(entryWord, pattern, MAX_DEPTH, progress) {
  entryWord = entryWord && entryWord.trim();
  if (!entryWord) return;

  entryWord = entryWord.toLocaleLowerCase();

  const insertPosition = pattern.indexOf('...');
  if (insertPosition < 0) {
    throw new Error('Query pattern is missing "..."');
  }
  const queryPosition = pattern.indexOf('[query]');
  if (queryPosition < 0) {
    throw new Error('Query pattern is missing "[query]" keyword');
  }

  if (insertPosition < queryPosition) {
    throw new Error('[query] should come before ...');
  }

  let cancelled = false;
  let pendingResponse;
  let graph = require('ngraph.graph')();
  graph.maxDepth = MAX_DEPTH;
  let queue = [];
  let requestDelay = 300 + Math.random() * 100;
  progress.startDownload();

  startQueryConstruction();

  return {
    dispose,
    graph
  }

  function dispose() {
    cancelled = true;
    if (pendingResponse) {
      pendingResponse.cancel();
      pendingResponse = null;
    }
  }

  function startQueryConstruction() {
    graph.addNode(entryWord, {depth: 0});
    fetchNext(entryWord);
  }

  function loadSiblings(parent, results) {
    let q = fullQuery(parent).toLocaleLowerCase();
    var parentNode = graph.getNode(parent);

    if (!parentNode) {
      throw new Error('Parent is missing for ' + parent);
    }

    results.filter(x => x.toLocaleLowerCase().indexOf(q) === 0)
      .map(x => x.substring(q.length))
      .forEach(other => {
        const hasOtherNode = graph.hasNode(other);
        const hasOtherLink = graph.getLink(other, parent) || graph.getLink(parent, other);
        if (hasOtherNode) {
          if (!hasOtherLink) {
            graph.addLink(parent, other);
          }
          return;
        }

        let depth = parentNode.data.depth + 1;
        graph.addNode(other, {depth});
        graph.addLink(parent, other);
        if (depth < MAX_DEPTH) queue.push(other);
      });

    setTimeout(loadNext, requestDelay);
  }

  function loadNext() {
    if (cancelled) return;
    if (queue.length === 0) {
      bus.fire('graph-ready', graph);
      return;
    }

    let nextWord = queue.shift();
    fetchNext(nextWord);
    progress.updateLayout(queue.length, nextWord);
  }

  function fetchNext(query) {
    pendingResponse = getResponse(fullQuery(query));
    pendingResponse
      .then(res => onPendingReady(res, query))
      .catch((msg) => {
        const err = 'Failed to download ' + query + '; Message: ' + msg;
        console.error(err);
        progress.downloadError(err)
        loadNext();
      });
  }

  function onPendingReady(res, query) {
    if (res.length >= 2) {
      loadSiblings(query, res[1]);
    } else {
      console.error(res);
      throw new Error('Unexpected response');
    }
  }

  function fullQuery(query) {
    return pattern.replace('[query]', query).replace('...', '');
  }

  function getResponse(query) {
    return jsonpFetch('//suggestqueries.google.com/complete/search?client=firefox&q=' + encodeURIComponent(query));
  }
}

И это то, что я до сих пор имел в R:

# This function builds a graph from Google's Auto-Suggestions

buildGraph <- function(entryWord, pattern) {

  graph <- igraph::make_empty_graph() # setup empty graph

  entryWord <- trimws(entryWord) #remove leading/trailing whitespace
  entryWord <- tolower(entryWord) # lowercase technology name

  requestDelay <- 0.3 + runif(1, 0, 1) * 0.1 # 300 milliseconds (0.3 seconds) + some number between 0 and 1 * 100 milliseconds (0.1 seconds)

  startQueryConstruction()

  dispose <- function() {
    cancelled <- TRUE
    if (pendingResponse) {
      # pendingResponse.cancel();
      # pendingResponse = null;
    }
  }

  startQueryConstruction <- function() {
    graph %>% igraph::add.vertices(entryWord)
    fetchNext(entryWord)
  }

  loadSiblings <- function(parent, results) {
    q = tolower(fullQuery(parent))
    parentNode <- igraph::vertex_attr(graph, parent)

    if (!parentNode) {
      # throw new Error('Parent is missing for ' + parent);
      stderr(paste0('Parent is missing for ', parent))
    }

    # results.filter(x => x.toLocaleLowerCase().indexOf(q) === 0)
  #     .map(x => x.substring(q.length))
  #     .forEach(other => {
  #       const hasOtherNode = graph.hasNode(other);
  #       const hasOtherLink = graph.getLink(other, parent) || graph.getLink(parent, other);
  #       if (hasOtherNode) {
  #         if (!hasOtherLink) {
  #           graph.addLink(parent, other);
  #         }
  #         return;
  #       }
  #       
  #       let depth = parentNode.data.depth + 1;
  #       graph.addNode(other, {depth});
  #       graph.addLink(parent, other);
  #       if (depth < MAX_DEPTH) queue.push(other);
  #       });
  #     
  #     setTimeout(loadNext, requestDelay);
  # }

  loadNext <- function() {
    # if (cancelled) return;
    if (length(queue) == 0) {
      # bus.fire('graph-ready', graph)
      # return;
    }

    nextWord <- queue.shift() # what is queue.shift in R?????
    fetchNext(nextWord)
    # progress.updateLayout(queue.length, nextWord) -- I think this is only for Vue UI
  }

  fetchNext <- function(query) {
    pendingResponse = getResponse(query)
    pendingResponse %...>%
       res = onPendingReady(res, query) %...!%
        (function(error) {
          print(paste("Failed to download: ", query, "; Message: ", error$message))
          loadNext()
        })
  }

  onPendingReady <- function(res, query) {
    if (length(res) >= 2) {
      loadSiblings(query, res[1])
    } else {
      # catch and print error
      # console.error(res)
      # throw error
      # throw new Error('Unexpected response');
    }
  }

  fullQuery <- function(query) {
    # return pattern.replace('[query]', query).replace('...', '')
  }

  getResponse <- function(query) {
    json_response <- future::future(jsonlite::fromJSON('//suggestqueries.google.com/complete/search?client=firefox&q=' + encodeURIComponent(query)))
    return(json_response)
  }


}

Обратите внимание, что я включил некоторые закомментированные некоторыестроки кода JavaScript, где я не уверен, что такое эквивалент RБольшая часть мрачного кода для меня сосредоточена на том, как делать вещи в igraph и как делать вещи асинхронно в R (используя promises и / или futures).

Заранее спасибо!