Questions tagged [finite-state-machine]
The finite-state-machine tag has no usage guidance.
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Can a state machine transition depend on the previous state?
I was wondering what the state machine for a video player would be like.
I can think of two states : playing and paused.
When the video is playing and the user clicks on a point in the progress ...
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1answer
42 views
What is the relationship between event driven design and state machines/charts?
I'm trying to understand event driven design better and have not picked up a book on it yet. But just from others explaining it to me it seems to be really similar to state machines/charts. What are ...
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How to handle state of an object? And how to enrich the state transition logic?
I am designing a class that has a state. I wonder if I should expose that state in the interface in view of allowing a decorator to enrich the state transition logic.
Shall my design expose ...
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2answers
94 views
If a business's workflow steps can reside solely in a database, is there a reason to use a workflow engine to accomplish those steps?
I found various libraries in C#, PHP, Python, etc. for workflows. By workflow I mean something like an employee wants personal time and that request starts with the employee and finishes in some ...
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2answers
333 views
Why do I need a game loop with states, instead of init the next state in current state directly?
For example, it is common to see games with game loop and states:
stateChanged(){
switch(state){
STATE.PLAYER_SELECT_CHARACTER:
this.currentController=new PlayerSelectCharacterController()...
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0answers
54 views
Hierarchical state machine. Is there a term for the deepest nested state in a state configuration?
A flat state machine has one active state. In a hierarchical state machine (HSM), if the HSM is in a child state, it's also in it's parent state. So, an active state configuration of an HSM consists ...
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2answers
73 views
Can my state machines use state that is derived from model data?
I'm putting together some ideas and personal conventions on how to configure state machines when using a language specific library.
Because I'm adding state machines to existing model classes in my ...
2
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1answer
59 views
Using state machines when managing remote resources
So I’ve got a service I’m trying to clean up. It responds to requests by starting a stopped server on Amazon EC2, waiting for it to come online, then configures a 3rd party piece of software on the ...
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1answer
142 views
Finite State Machine odd number of bc at the end
I had this question in a school test:
Design a non-deterministic FSM that receives all words over {a,b,c} that:
Start with cc.
Contain at least 1 ab or aca.
Ends with an odd number of (...
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1answer
182 views
Why are next-state function and output functions of an FSM combinational functions?
From my understanding, combinational logic is dependent solely on input, and sequential logic involves state--memory.
When explaining a finite state machine (FSM), however, it is said that an FSM ...
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4answers
2k views
So what exactly is a final state of a finite state machine?
I am playing around the state machine concept trying to better understand the best areas of their application. The formal definition of an FSM contains the following elements:
finite non-empty set of ...
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1answer
840 views
Finite State Vending Machine Diagram
In class, we are asked to draw a finite state machine with the following instructions:
Design a finite state machine to model a vending machine that accepts
only quarters and gives a container of ...
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1answer
405 views
State machine with database records
I was re-learning about state diagrams this weekend, and realized that I may have been using them for years without realizing it.
Suppose i have an order record, with a bunch of fields including ...
2
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2answers
98 views
How to model a statemachine in this case
I have a system where lot of messages come and go over network, each message to be sent or received goes through several states, state change occurs based on external events for example if the linked ...
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0answers
33 views
How do I know the depth of “k” for characterising set when testing FSM?
I am supposed to design the tests for state machine software. I have covered all states and all transitions. The last step is to detect the hidden states (states that look the same but internally ...
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0answers
79 views
Design for consuming list items for a state machine like structure
I'm trying to improve this document parser and there is one main loop that goes over all of the main elements (let's call them Nodes). Each step (Step) can either Consume or Ignore the Node that it is ...
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4answers
1k views
How should state machines handle exceptions in actions?
State machines, for example UML state machines, statecharts or other finite state machines, allow actions to be executed when a state machine takes a transition between states or is within a state.
...
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1answer
654 views
How does one combine the state pattern and the component pattern?
Suppose we have a class Player with classes PhysicsComponent, InputComponent and StandingState, DuckingState.
The class Player itself does not have an input function, the InputComponent does. But ...
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1answer
52 views
Do I have to state the value of elapsed time in state-charts?
I am modelling a system that requires a state-chart before implementation.
Given These Images:
Main Questions:
Can I use the word "Elapsed Time" if I do not know how long it will take to finish the ...
5
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2answers
387 views
A simple GUI app: states
I'm making a Windows Forms app:
It is client-server. Authorization, then load some data from server, then send back some statistics from time to time.
You should go through a bootstrapping procedure, ...
7
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2answers
571 views
How to store and validate data between state transitions?
I'm developing a largeish application that will have custom finite state machines. That is, the admin users of the application will be able to create their own state machines, limited by little pieces ...
3
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1answer
180 views
UML “direct substate” vs “transitively nested substate”
I am reading through Wikipedia's page on UML state machines. I don't understand where it says:
A nested state is called a direct substate when it is not contained by
any other state; otherwise, ...
3
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1answer
147 views
In OOP which object is common to update the state of an object when working with State Machines?
I'm about to implement my first State Machine and I'm left with one question, which is the acceptable coding form on who should change the state of the object/entity? Should the StateMachine change ...
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2answers
451 views
Trouble with circular dependency in state machine design
I am trying to develop the structure for a basic state machine that can also take in input and produce output. I've hit a bit of a mental block in trying to figure out how to model the relationship ...
2
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1answer
304 views
Is state pattern a wise architecture for a diagram application?
I'm designing a vector drawing app.
I need to implemente copy and paste, shapes insertion, deletion and transforming while still being capable of including new tools with easy in the future.
The way ...
3
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1answer
771 views
State machine with additional variable
When implementing a state machine and it comes to the fact that a transition depends on an external boolean a, or an enum value b which can be one out of three (which are set somewhere else in the ...
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2answers
2k views
Language to describe Finite State Machine
I'm doing a lot of code analysis using lexer and finite state machine. For time being I'm using table to describe FSM:
| token | current state | target state |
+-------+---------------+--------------+...
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2answers
881 views
State Design Pattern
I've come across the following State Design Pattern which seems extremely logical and simple to implement:
class CeilingFanPullChain
{
private State m_current_state;
public ...
0
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1answer
331 views
How do I manage a large state graph when building a scaleable finite state machine?
Lately I've been working on a project that involves parsing a toy domain-specific-language. While building it out, I realized that an efficient way to handle parsing tokens would be to represent the ...
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3answers
650 views
Can a generic piece of C code be converted to an FSM?
I understand that any language worth its salt can encode a Finite state machine. My question is the opposite, is it possible to convert an arbitrary piece of code ( say in C ) to a functionally ...
2
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4answers
114 views
How to explain to a vendor that when erroneous data is deleted/deactivated the application future state should be as if the data was never entered?
A major application we use has a bug that the vendor is calling (a swear word in our business) "working as designed".
As a programmer / system analyst this is a bug - and against all I have been ...
7
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1answer
682 views
Finite state machine menu design
I'm creating an FSM in python (it's a step sequencer and sample pad based on a Raspberry Pi 2).
Right now there are two states and the third is the Menu. This is handled by a class System which ...
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1answer
2k views
What is the alternative design pattern of a state machine that may have recursive state change?
I have a state machine like code, which has state A,B and C, with a function changeState(char i) which can change the state of a system, and each state can also call changeState(char i) to switch the ...
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2answers
174 views
Is there a well defined notion of 'before' and 'after' in finite state machines?
When working with finite state machines, is there or can there be a well defined concept of 'before' and 'after'.
The ordering would, for example, tell me that one state is always considered to be '...
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4answers
1k views
How is a state machine different from any other computer program?
I have seen several implementations of "State Machines" on github. As far as I understand, a state machine takes input that may or may not transform its state into one of a finite set of other states. ...
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1answer
1k views
Should I use the State Design pattern for only two states? Also, what if one object's state is affected by another state?
If you only have two states for an object, is it worth it to still use the State Design pattern?
The context is a multi-player, turn-based game environment where there are Game "Tables" that a player ...
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2answers
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Should I use multiple state machines for a layered protocol?
When implementing a layered communications protocol are layers commonly implemented as state machines?
I have an implementation of PMBus I am currently working on for an embedded device. I have a ...
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0answers
279 views
Finite State Machine user input tree
I'm drawing a Finite State Machine (which I'll have to implement later on) which is semi-automatic, i.e. some transitions require user input, some are decided on internal value.
The problem is that ...
3
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1answer
721 views
Model of simple traffic simulation [closed]
I want to write a simple traffic simulation with one road intersection. First I thought of a cellular automata in the model but it should not be limited by an underlying discrete grid system so the ...
3
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2answers
211 views
Is there a good way (pattern) for adding a state to a finite state machine
So I'm working on a roguelike, and planning to represent the monsters using a finite state machine
spot PC
wander------------------->move
^ ^ |
| \ ...
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1answer
129 views
How should I design a wizard for generating requirements and documentation
I'm currently working in an industry where extensive documentation is required, but the apps I'm writing are all pretty much cookie cutter at a high level. What I'd like to do is build an app that ...
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1answer
641 views
Implementing state-driven agents within an Entity-Component-System approach
A state-driven agent is an agent that performs an action based on its current state. The logic can be implemented through the use of a D-FSM that changes state depending on the Agent's "perception" ...
3
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1answer
461 views
How to process document state transition?
Imagine there is an application (ASP.NET MVC) that processes some documents. The document must be revised several times by different group of users.
state/role rules:
simple user can only publish ...
2
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0answers
466 views
State Pattern Code for embedded device - Dependency Injection of Device Objects in Context and State Classes
I'm wrestling with some code and I think I've finally gotten some state pattern code working with my events.
I've got a simplified system that will work like this:
This is my first go with State ...
5
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1answer
152 views
How to Recover from Inconsistent Job State without Database Polling
I'm working on scaling an application which is currently polling a mySQL database to send async jobs to a background processing system.
A state machine is being used to keep track of the entities ...
5
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1answer
4k views
How to Implement a Parallel Workflow
I'm trying to implement a parallel split task using a workflow system. I'm using .NET but my process is very simple and I don't want to use WF or anything heavy like that.
I've tried using Stateless. ...
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2answers
1k views
Dependency injection with Finite State Machines and the Interface Segregation Principle
I am trying to figure out what is the best way to setup a FSM and also keep my interfaces clean and use an IOC container to use DI.
Let's just visit the Head First design pattern textbook example of ...
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1answer
538 views
Can all business logic be decomposed as a (declarative) state diagram on simple crud operations and conditionals?
This seems an extreme question probably but I'm wondering anyhow:
Can all business logic be decomposed as a (declarative) state diagram on simple crud operations and conditionals?
Already a lot of ...
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1answer
213 views
Converting a DFA to an NFA
I have an assignment to convert various language descriptions into NFAs and DFAs.
Having graduated with my CompSci B.S. years ago and not touching the topic until my M.S. program, I am racking my ...
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4answers
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Conceptually, how does one make a rules/constraints (not graphics/physics) engine for a game
I want to make a simple game similar to the choose-your-own-adventure books. The player is presented with a narrative text and gets to choose his action from a list of possibilities. This, in turn, ...
