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JavaScriptGeneratorsIteratorsAsync

JavaScript Generators and Iterators

Master generators and iterators in JavaScript. From lazy evaluation to async generators to custom iterables.

B
Bootspring Team
Engineering
April 14, 2021
7 min read

Generators create iterable sequences with lazy evaluation. Here's how to use them effectively.

Basic Generators

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Infinite Sequences

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Passing Values to Generators

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Generator Delegation

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Custom Iterables

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Async Generators

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Generator Utilities

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Lazy Evaluation

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Generator for State Management

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Error Handling

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Real-World Example: Pagination

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Best Practices

When to use: ✓ Large or infinite sequences ✓ Lazy evaluation needed ✓ Custom iteration logic ✓ Async data streams Performance: ✓ Use for lazy evaluation ✓ Avoid for small fixed arrays ✓ Clean up with return() ✓ Handle errors properly Patterns: ✓ Combine with async/await ✓ Use yield* for delegation ✓ Create reusable utilities ✓ Implement Symbol.iterator

Conclusion

Generators enable lazy evaluation and custom iteration. Use them for large datasets, infinite sequences, and async streams. Combine with utility functions like map, filter, and take for powerful data processing pipelines.

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