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47 lines
1.1 KiB
47 lines
1.1 KiB
3 years ago
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/**
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* Obliterator Iter Function
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* ==========================
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*
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* Function coercing values to an iterator. It can be quite useful when needing
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* to handle iterables and iterators the same way.
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*/
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var Iterator = require('./iterator.js');
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var support = require('./support.js');
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var ARRAY_BUFFER_SUPPORT = support.ARRAY_BUFFER_SUPPORT;
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var SYMBOL_SUPPORT = support.SYMBOL_SUPPORT;
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function iterOrNull(target) {
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// Indexed sequence
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if (
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typeof target === 'string' ||
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Array.isArray(target) ||
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(ARRAY_BUFFER_SUPPORT && ArrayBuffer.isView(target))
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)
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return Iterator.fromSequence(target);
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// Invalid value
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if (typeof target !== 'object' || target === null) return null;
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// Iterable
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if (SYMBOL_SUPPORT && typeof target[Symbol.iterator] === 'function')
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return target[Symbol.iterator]();
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// Iterator duck-typing
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if (typeof target.next === 'function') return target;
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// Invalid object
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return null;
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}
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module.exports = function iter(target) {
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var iterator = iterOrNull(target);
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if (!iterator)
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throw new Error(
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'obliterator: target is not iterable nor a valid iterator.'
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);
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return iterator;
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};
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