46 lines
1.6 KiB
Markdown
46 lines
1.6 KiB
Markdown
---
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layout: pattern
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title: Trampoline
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folder: trampoline
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permalink: /patterns/trampoline/
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categories: Behavior
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tags:
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- Java
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- Difficulty-Intermediate
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- Performance
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- Recursion
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---
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## Intent
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Trampoline pattern is used for implementing algorithms recursively in Java without blowing the stack
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and to interleave the execution of functions without hard coding them together
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It is possible by representing a computation in one of 2 states : done | more
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(completed with result, or a reference to the reminder of the computation,
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something like the way a java.util.Supplier does).
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## Explanation
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Trampoline pattern allows to define recursive algorithms by iterative loop.
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## Applicability
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Use the Trampoline pattern when
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* For implementing tail recursive function. This pattern allows to switch on a stackless operation.
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* For interleaving the execution of two or more functions on the same thread.
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## Known uses(real world examples)
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* Trampoline refers to using reflection to avoid using inner classes, for example in event listeners.
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The time overhead of a reflection call is traded for the space overhead of an inner class.
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Trampolines in Java usually involve the creation of a GenericListener to pass events to an outer class.
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## Tutorials
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* [Trampolining: a practical guide for awesome Java Developers](https://medium.com/@johnmcclean/trampolining-a-practical-guide-for-awesome-java-developers-4b657d9c3076)
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* [Trampoline in java ](http://mindprod.com/jgloss/trampoline.html)
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## Credits
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* [library 'cyclops-react' uses the pattern](https://github.com/aol/cyclops-react)
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