iter-tools-es/impls/$split-on-any-seq/async-split-on-any-seq.js

The iterable toolbox

const {
  asyncIterableCurry
} = require('../../internal/async-iterable.js');

const {
  asyncSeqsToArray
} = require('../../internal/async-any-seq.js');

const {
  __startsWithSeq
} = require('../$starts-with-seq/starts-with-seq.js');

const {
  __asyncWindowAhead
} = require('../$window-ahead/async-window-ahead.js');

const {
  __asyncSpliterate
} = require('../$spliterate/async-spliterate.js');

function getMatchingLength(buffer, separatorSeqs, same) {
  for (const subsequence of separatorSeqs) {
    if (__startsWithSeq(buffer, subsequence, same)) {
      return subsequence.length;
    }
  }

  return 0;
}

async function* asyncAnySeqspliterator(split, {
  separatorSeqs,
  same
}, source) {
  const maxMatchLength = separatorSeqs.reduce((max, {
    length
  }) => Math.max(max, length), 1);
  let skip = 0;

  for await (const buffer of __asyncWindowAhead(source, maxMatchLength, {
    useFiller: false
  })) {
    if (skip > 0) {
      skip--;
      continue;
    }

    const matchingLength = getMatchingLength(buffer, separatorSeqs, same);

    if (matchingLength > 0) {
      yield split;
      skip = matchingLength - 1;
    } else {
      yield buffer.get(0);
    }
  }
}

async function* __asyncSplitOnAnySeq(source, separatorSeqs, same = Object.is) {
  const separatorSeqsArr = (await asyncSeqsToArray(separatorSeqs)).filter(s => s.length > 0);
  yield* __asyncSpliterate(source, asyncAnySeqspliterator, {
    separatorSeqs: separatorSeqsArr.sort((a, b) => b.length - a.length),
    same
  });
}

exports.__asyncSplitOnAnySeq = __asyncSplitOnAnySeq;
const asyncSplitOnAnySeq = /*#__PURE__*/asyncIterableCurry(__asyncSplitOnAnySeq, {
  minArgs: 1,
  maxArgs: 2
});
exports.asyncSplitOnAnySeq = asyncSplitOnAnySeq;