What are the performance advantage of Elixir's defstruct?
My understanding of Elixir's structure is that;
1. It can't hold keys other than ones defined at compile time.
2. It can have default values, which is evaluated at compile time.
Is there are any performance advantage?
Also, is there anything that I'm missing?
elixir structure
asked Nov 14 '18 at 6:02
HelloWorldHelloWorld
97110
add a comment |
My understanding of Elixir's structure is that;
1. It can't hold keys other than ones defined at compile time.
2. It can have default values, which is evaluated at compile time.
Is there are any performance advantage?
Also, is there anything that I'm missing?
elixir structure
asked Nov 14 '18 at 6:02
HelloWorldHelloWorld
97110
1
From the docs: "Structs can also be used in pattern matching, both for matching on the value of specific keys as well as for ensuring that the matching value is a struct of the same type as the matched value." So you can win by pattern matching rather than using less performant algorithmic method - I guess.
– GavinBrelstaff
Nov 14 '18 at 7:52
add a comment |
My understanding of Elixir's structure is that;
1. It can't hold keys other than ones defined at compile time.
2. It can have default values, which is evaluated at compile time.
Is there are any performance advantage?
Also, is there anything that I'm missing?
elixir structure
asked Nov 14 '18 at 6:02
HelloWorldHelloWorld
97110
My understanding of Elixir's structure is that;
1. It can't hold keys other than ones defined at compile time.
2. It can have default values, which is evaluated at compile time.
Is there are any performance advantage?
Also, is there anything that I'm missing?
elixir structure
elixir structure
asked Nov 14 '18 at 6:02
HelloWorldHelloWorld
97110
asked Nov 14 '18 at 6:02
HelloWorldHelloWorld
97110
asked Nov 14 '18 at 6:02
HelloWorldHelloWorld
97110
asked Nov 14 '18 at 6:02
HelloWorldHelloWorld
97110
asked Nov 14 '18 at 6:02
HelloWorldHelloWorld
97110
97110
1
From the docs: "Structs can also be used in pattern matching, both for matching on the value of specific keys as well as for ensuring that the matching value is a struct of the same type as the matched value." So you can win by pattern matching rather than using less performant algorithmic method - I guess.
– GavinBrelstaff
Nov 14 '18 at 7:52
add a comment |
1
From the docs: "Structs can also be used in pattern matching, both for matching on the value of specific keys as well as for ensuring that the matching value is a struct of the same type as the matched value." So you can win by pattern matching rather than using less performant algorithmic method - I guess.
– GavinBrelstaff
Nov 14 '18 at 7:52
1
1
From the docs: "Structs can also be used in pattern matching, both for matching on the value of specific keys as well as for ensuring that the matching value is a struct of the same type as the matched value." So you can win by pattern matching rather than using less performant algorithmic method - I guess.
– GavinBrelstaff
Nov 14 '18 at 7:52
From the docs: "Structs can also be used in pattern matching, both for matching on the value of specific keys as well as for ensuring that the matching value is a struct of the same type as the matched value." So you can win by pattern matching rather than using less performant algorithmic method - I guess.
– GavinBrelstaff
Nov 14 '18 at 7:52
add a comment |
2 Answers
2
active
oldest
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The main advantage of struct is not any performance, but code readability and correctness. Consider something like %{id: 123} - we don't know what that map represents. With structs we can have %Person{id: 123} and %Company{id: 123}, and these will be different things. Furthermore one can easily express which one is expected with pattern matching, as mentioned by GavinBrelstaff. Another example of a feature in struct aimed at correctness is @enforce_keys - by setting it in your struct you make sure that any normally created instance of it will have the given keys present.
answered Nov 14 '18 at 14:06
Paweł ObrokPaweł Obrok
17.6k56060
add a comment |
Well, Elixir is open source. As it might be easily seen from the implementation of Kernel.defstruct/1, everything it does is it defines __struct__ method on the module where it was called (only the false part of the case could be considered without the loss of generality).
Everything else there is responsible for informing the Elixir compiler about this struct to enable new syntax (%MyStruct{}) for it and to store some metainformation about the struct into compiler globals.
Underneath the struct is represented by bare map %{} and there could not be any room for any performance boost.
answered Nov 14 '18 at 13:48
Aleksei MatiushkinAleksei Matiushkin
81.5k95591
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
The main advantage of struct is not any performance, but code readability and correctness. Consider something like %{id: 123} - we don't know what that map represents. With structs we can have %Person{id: 123} and %Company{id: 123}, and these will be different things. Furthermore one can easily express which one is expected with pattern matching, as mentioned by GavinBrelstaff. Another example of a feature in struct aimed at correctness is @enforce_keys - by setting it in your struct you make sure that any normally created instance of it will have the given keys present.
answered Nov 14 '18 at 14:06
Paweł ObrokPaweł Obrok
17.6k56060
add a comment |
The main advantage of struct is not any performance, but code readability and correctness. Consider something like %{id: 123} - we don't know what that map represents. With structs we can have %Person{id: 123} and %Company{id: 123}, and these will be different things. Furthermore one can easily express which one is expected with pattern matching, as mentioned by GavinBrelstaff. Another example of a feature in struct aimed at correctness is @enforce_keys - by setting it in your struct you make sure that any normally created instance of it will have the given keys present.
answered Nov 14 '18 at 14:06
Paweł ObrokPaweł Obrok
17.6k56060
add a comment |
The main advantage of struct is not any performance, but code readability and correctness. Consider something like %{id: 123} - we don't know what that map represents. With structs we can have %Person{id: 123} and %Company{id: 123}, and these will be different things. Furthermore one can easily express which one is expected with pattern matching, as mentioned by GavinBrelstaff. Another example of a feature in struct aimed at correctness is @enforce_keys - by setting it in your struct you make sure that any normally created instance of it will have the given keys present.
answered Nov 14 '18 at 14:06
Paweł ObrokPaweł Obrok
17.6k56060
The main advantage of struct is not any performance, but code readability and correctness. Consider something like %{id: 123} - we don't know what that map represents. With structs we can have %Person{id: 123} and %Company{id: 123}, and these will be different things. Furthermore one can easily express which one is expected with pattern matching, as mentioned by GavinBrelstaff. Another example of a feature in struct aimed at correctness is @enforce_keys - by setting it in your struct you make sure that any normally created instance of it will have the given keys present.
answered Nov 14 '18 at 14:06
Paweł ObrokPaweł Obrok
17.6k56060
answered Nov 14 '18 at 14:06
Paweł ObrokPaweł Obrok
17.6k56060
answered Nov 14 '18 at 14:06
Paweł ObrokPaweł Obrok
17.6k56060
answered Nov 14 '18 at 14:06
Paweł ObrokPaweł Obrok
17.6k56060
17.6k56060
add a comment |
add a comment |
Well, Elixir is open source. As it might be easily seen from the implementation of Kernel.defstruct/1, everything it does is it defines __struct__ method on the module where it was called (only the false part of the case could be considered without the loss of generality).
Everything else there is responsible for informing the Elixir compiler about this struct to enable new syntax (%MyStruct{}) for it and to store some metainformation about the struct into compiler globals.
Underneath the struct is represented by bare map %{} and there could not be any room for any performance boost.
answered Nov 14 '18 at 13:48
Aleksei MatiushkinAleksei Matiushkin
81.5k95591
add a comment |
Well, Elixir is open source. As it might be easily seen from the implementation of Kernel.defstruct/1, everything it does is it defines __struct__ method on the module where it was called (only the false part of the case could be considered without the loss of generality).
Everything else there is responsible for informing the Elixir compiler about this struct to enable new syntax (%MyStruct{}) for it and to store some metainformation about the struct into compiler globals.
Underneath the struct is represented by bare map %{} and there could not be any room for any performance boost.
answered Nov 14 '18 at 13:48
Aleksei MatiushkinAleksei Matiushkin
81.5k95591
add a comment |
Well, Elixir is open source. As it might be easily seen from the implementation of Kernel.defstruct/1, everything it does is it defines __struct__ method on the module where it was called (only the false part of the case could be considered without the loss of generality).
Everything else there is responsible for informing the Elixir compiler about this struct to enable new syntax (%MyStruct{}) for it and to store some metainformation about the struct into compiler globals.
Underneath the struct is represented by bare map %{} and there could not be any room for any performance boost.
answered Nov 14 '18 at 13:48
Aleksei MatiushkinAleksei Matiushkin
81.5k95591
Well, Elixir is open source. As it might be easily seen from the implementation of Kernel.defstruct/1, everything it does is it defines __struct__ method on the module where it was called (only the false part of the case could be considered without the loss of generality).
Everything else there is responsible for informing the Elixir compiler about this struct to enable new syntax (%MyStruct{}) for it and to store some metainformation about the struct into compiler globals.
Underneath the struct is represented by bare map %{} and there could not be any room for any performance boost.
answered Nov 14 '18 at 13:48
Aleksei MatiushkinAleksei Matiushkin
81.5k95591
answered Nov 14 '18 at 13:48
Aleksei MatiushkinAleksei Matiushkin
81.5k95591
answered Nov 14 '18 at 13:48
Aleksei MatiushkinAleksei Matiushkin
81.5k95591
answered Nov 14 '18 at 13:48
Aleksei MatiushkinAleksei Matiushkin
81.5k95591
81.5k95591
add a comment |
add a comment |
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1
From the docs: "Structs can also be used in pattern matching, both for matching on the value of specific keys as well as for ensuring that the matching value is a struct of the same type as the matched value." So you can win by pattern matching rather than using less performant algorithmic method - I guess.
– GavinBrelstaff
Nov 14 '18 at 7:52