[jira] [Comment Edited] (THRIFT-3467) Go Maps for Thrift Sets Should Have Values of Type struct{}

["Tom Deering (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/THRIFT-3467?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15228245#comment-15228245 ] 

Tom Deering edited comment on THRIFT-3467 at 4/6/16 1:35 PM:
-------------------------------------------------------------

[~jensg], I understand [~creker]'s argument that if bool values are given, then one doesn't have to use the "comma, ok" idiom to check if an item is in the set (Go map). However, I'd give 3 counterarguments in reply:

1. When you read code where a map has non-empty values (eg of type bool), it is natural to assume that the values have meaning. But for a set encoding, the values have no meaning by definition, so this is misleading to a reader of your code.
2. The "comma, ok" idiom in Go is common and well-understood, and is the standard safe way to check if a map key is defined.
3. Storing unnecessary booleans as map values wastes a small (though not exorbitant) amount of memory.

In my opinion, bool map values for a set encoding are a misleading, unnecessary attempt to avoid using a standard Go idiom. One man's opinion.

FYI, in an initializer, one can use {} as shorthand for struct{}{}. That will help make your code snippet look less bad :)


was (Author: tdeering):
I understand [~creker]'s argument that if bool values are given, then one doesn't have to use the "comma, ok" idiom to check if an item is in the set (Go map). However, I'd give 3 counterarguments in reply:

1. When you read code where a map has non-empty values (eg of type bool), it is natural to assume that the values have meaning. But for a set encoding, the values have no meaning by definition, so this is misleading to a reader of your code.
2. The "comma, ok" idiom in Go is common and well-understood, and is the standard safe way to check if a map key is defined.
3. Storing unnecessary booleans as map values wastes a small (though not exorbitant) amount of memory.

In my opinion, bool map values for a set encoding are a misleading, unnecessary attempt to avoid using a standard Go idiom. One man's opinion.

FYI, in an initializer, one can use {} as shorthand for struct{}{}. That will help make your code snippet look less bad :)

> Go Maps for Thrift Sets Should Have Values of Type struct{} 
> ------------------------------------------------------------
>
>                 Key: THRIFT-3467
>                 URL: https://issues.apache.org/jira/browse/THRIFT-3467
>             Project: Thrift
>          Issue Type: Improvement
>          Components: Go - Compiler
>    Affects Versions: 0.9.3
>            Reporter: Tom Deering
>            Assignee: artem antonenko
>              Labels: golang
>
> Sets in Thrift are currently turned into maps with boolean values in Go. Example:
> Thrift
> {code}
> namespace go bug
> service FooService{
> 	void bar (1:set<string> foos)
> }
> {code}
> Go
> {code}
> func (p *FooServiceClient) Bar(foos map[string]bool) (err error) 
> {code}
> Boolean map values waste memory. Map values should be of the zero-byte struct{} type.



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