Questions tagged [side-effect]
The side-effect tag has no usage guidance.
48
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What side-effects, if any, are okay when importing a python module?
Generally, modules should not have side effects. However, in a lot of cases, the side-effects are hard to avoid or may be desirable. There are also popular packages with on-import side-effects.
Which ...
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If a function mutates outer state during execution but reverts the outer state into original state after execution, does it still contain side effect?
According to What is a "side effect?", I know the side effect means changing outside world. But what if a function that changes the outside state during execution, but reverts the state to ...
- 2,009
1
vote
5
answers
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Should I repeat calculations twice to follow "return a value or have side-effects, but not both"?
According to Origin of "a method should return a value or have side-effects, but not both", a method should either return a value or have side-effect, but not both. However, I often see some ...
- 2,009
3
votes
1
answer
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How to handle a state machine side effect being optional?
I have a state machine that, as a side effect of going into a certain state, sends a message to a remote server. In some situations, however, I don't want the state machine to send that message, even ...
- 215
0
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3
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How to implement state machine side effect that needs data the state machine doesn't have
Given a state machine that implements a certain protocol. I need multiple instances of this protocol running, so I create multiple instances of this state machine. Each instance is associated with a ...
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Is there a non-deterministic function without side effects?
By definition, a pure function is deterministic + no side effect.
Is there any example for a function which has no side effects, but is non-deterministic? I.e., a function without side effects, but ...
- 281
0
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1
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How to test a function with several conditional nested side effects
In Python, consider a function like the following:
def main(*args):
value1 = pure_function1(*args)
if condition(value1):
value = side_effect1(value1)
if value:
...
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-4
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Does the HTTP specification fully define the semantics of request methods?
I see two possible interpretations of the semantics of request methods defined in the HTTP specification RFC 7231:
The intended effect of a request method is fully defined by the HTTP specification (...
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2
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A command as the intended effect of POST versus as the side effect of PUT
The intended effect (semantics) of the POST method is resource specific, e.g. executing a command with arguments:
POST /command HTTP/1.1
{"parameter-1": "argument-1", "...
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3
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2
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Is rebooting a server idempotent or not?
In his article RESTful Casuistry, Tim Bray claims that rebooting a server is not idempotent:
But I don’t buy it, and here’s why. If I want to update some fields in an existing resource, I’m inclined ...
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2
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334
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Can I enforce "functional core, imperative" shell with a framework?
The design pattern known as "functional core, imperative shell" is about separating side-effects from pure calculations, where business logic is supposed to be pure and then coordinated by ...
- 145
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Is having side-effects in constructor an anti-pattern?
I was trying to understand how to embed v8 engine in a C++ application and was trying to understand the following hello world problem as a result.
I found the code to be unreadable at first glance. e....
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2
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495
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Remove all side-effects from business logic
I'm looking for feedback for a design pattern that aims to remove all side-effects from business logic. I'm using PHP but the pattern can be applied to any OOP language. The point is to enforce pure ...
- 145
2
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2
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What's the value of IO Monad?
When I'm writing code in the form of IO Monad, I wonder what's real value of it.For example I have a function as def something(in: In): IO[Out]; my function is a pure function that **returns an impure ...
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Avoiding side effects in immutable class constructor
I rewrote a very long method in which some data is queried from a database, based on info about a particular account, which is queried first.
I split out the account info into an immutable inner ...
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