Go Patterns

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A curated collection of idiomatic design & application patterns for Go language.

Creational Patterns

| Pattern | Description | Status | |:-------:|:----------- |:------:| | Abstract Factory | Provides an interface for creating families of releated objects | ✘ | | Builder | Builds a complex object using simple objects | ✔ | | Factory Method | Defers instantiation of an object to a specialized function for creating instances | ✔ | | Object Pool | Instantiates and maintains a group of objects instances of the same type | ✔ | | Singleton | Restricts instantiation of a type to one object | ✔ |

Structural Patterns

| Pattern | Description | Status | |:-------:|:----------- |:------:| | Bridge | Decouples an interface from its implementation so that the two can vary independently | ✘ | | Composite | Encapsulates and provides access to a number of different objects | ✘ | | Decorator | Adds behavior to an object, statically or dynamically | ✔ | | Facade | Uses one type as an API to a number of others | ✘ | | Flyweight | Reuses existing instances of objects with similar/identical state to minimize resource usage | ✘ | | Proxy | Provides a surrogate for an object to control it's actions | ✔ |

Behavioral Patterns

| Pattern | Description | Status | |:-------:|:----------- |:------:| | Chain of Responsibility | Avoids coupling a sender to receiver by giving more than object a chance to handle the request | ✘ | | Command | Bundles a command and arguments to call later | ✘ | | Mediator | Connects objects and acts as a proxy | ✘ | | Memento | Generate an opaque token that can be used to go back to a previous state | ✘ | | Observer | Provide a callback for notification of events/changes to data | ✔ | | Registry | Keep track of all subclasses of a given class | ✘ | | State | Encapsulates varying behavior for the same object based on its internal state | ✘ | | Strategy | Enables an algorithm's behavior to be selected at runtime | ✔ | | Template | Defines a skeleton class which defers some methods to subclasses | ✘ | | Visitor | Separates an algorithm from an object on which it operates | ✘ |

Synchronization Patterns

| Pattern | Description | Status | |:-------:|:----------- |:------:| | Condition Variable | Provides a mechanism for threads to temporarily give up access in order to wait for some condition | ✘ | | Lock/Mutex | Enforces mutual exclusion limit on a resource to gain exclusive access | ✘ | | Monitor | Combination of mutex and condition variable patterns | ✘ | | Read-Write Lock | Allows parallel read access, but only exclusive access on write operations to a resource | ✘ | | Semaphore | Allows controlling access to a common resource | ✔ |

Concurrency Patterns

| Pattern | Description | Status | |:-------:|:----------- |:------:| | N-Barrier | Prevents a process from proceeding until all N processes reach to the barrier | ✘ | | Bounded Parallelism | Completes large number of independent tasks with resource limits | ✔ | | Broadcast | Transfers a message to all recipients simultaneously | ✘ | | Coroutines | Subroutines that allow suspending and resuming execution at certain locations | ✘ | | Generators | Yields a sequence of values one at a time | ✔ | | Reactor | Demultiplexes service requests delivered concurrently to a service handler and dispatches them syncronously to the associated request handlers | ✘ | | Parallelism | Completes large number of independent tasks | ✔ | | Producer Consumer | Separates tasks from task executions | ✘ |

Messaging Patterns

| Pattern | Description | Status | |:-------:|:----------- |:------:| | Fan-In | Funnels tasks to a work sink (e.g. server) | ✔ | | Fan-Out | Distributes tasks among workers (e.g. producer) | ✔ | | Futures & Promises | Acts as a place-holder of a result that is initially unknown for synchronization purposes | ✘ | | Publish/Subscribe | Passes information to a collection of recipients who subscribed to a topic | ✔ | | Push & Pull | Distributes messages to multiple workers, arranged in a pipeline | ✘ |

Stability Patterns

| Pattern | Description | Status | |:-------:|:----------- |:------:| | Bulkheads | Enforces a principle of failure containment (i.e. prevents cascading failures) | ✘ | | Circuit-Breaker | Stops the flow of the requests when requests are likely to fail | ✔ | | Deadline | Allows clients to stop waiting for a response once the probability of response becomes low (e.g. after waiting 10 seconds for a page refresh) | ✘ | | Fail-Fast | Checks the availability of required resources at the start of a request and fails if the requirements are not satisfied | ✘ | | Handshaking | Asks a component if it can take any more load, if it can't, the request is declined | ✘ | | Steady-State | For every service that accumulates a resource, some other service must recycle that resource | ✘ |

Profiling Patterns

| Pattern | Description | Status | |:-------:|:----------- |:------:| | Timing Functions | Wraps a function and logs the execution | ✔ |

Idioms

| Pattern | Description | Status | |:-------:|:----------- |:------:| | Functional Options | Allows creating clean APIs with sane defaults and idiomatic overrides | ✔ |

Anti-Patterns

| Pattern | Description | Status | |:-------:|:----------- |:------:| | Cascading Failures | A failure in a system of interconnected parts in which the failure of a part causes a domino effect | ✘ |