iter-tools-es/impls/$bisect/bisect.js

The iterable toolbox

const {
  iterableCurry
} = require('../../internal/iterable.js');

const {
  Bisector
} = require('../../internal/bisector.js');

const {
  __toArray
} = require('../$to-array/to-array.js');

const {
  __peekerate
} = require('../$peekerate/peekerate.js');

function* indexStrategy(split, {
  at
}, source) {
  const _source = at < 0 ? __toArray(source) : source;

  const idx = at < 0 ? _source.length + at : at;

  const peekr = __peekerate(_source);

  try {
    while (!peekr.done) {
      if (peekr.index === idx) yield split;
      yield peekr.value;
      peekr.advance();
    }
  } finally {
    peekr.return();
  }
}

exports.indexStrategy = indexStrategy;

function* conditionStrategy(split, {
  at: predicate
}, source) {
  let i = 0;
  let splat = false;

  for (const value of source) {
    if (!splat && predicate(value, i++)) {
      yield split;
      splat = true;
    }

    yield value;
  }
}

exports.conditionStrategy = conditionStrategy;

function __bisect(source, at) {
  const strategy = typeof at === 'number' ? indexStrategy : conditionStrategy;
  return new Bisector(source, strategy, {
    at
  });
}

exports.__bisect = __bisect;
const bisect = /*#__PURE__*/iterableCurry(__bisect, {
  forceSync: true
});
exports.bisect = bisect;