`const` syntax outside of `struct`

General Usage
, ,
1

Background:

In Agents.jl, any agent type being made from calling @agent is mutable, but with Julia versions >= 1.8 now we can specify particular fields as being const, which can help bring performance closer to immutable structs (see Types · The Julia Language). It would be nice to let users to specify fields as const if they like, to improve performance.

Related issue:

Question:

Is it possible to embed const syntax in @agent macro, as follows:

@agent YourAgentType{X} AnotherAgentType [OptionalSupertype] begin
        extra_property::X
        other_extra_property::Int
        const immutable_property::X # immutable type
        # etc...
end

Note that this will not even parse at all:

ERROR: syntax: expected assignment after "const"

It would be possible to rework the @agent syntax, to use:

@agent AnotherAgentType [OptionalSupertype] struct YourAgentType{X}
        extra_property::X
        other_extra_property::Int
        const immutable_property::X
        # etc...
end

However, that would be a breaking change, which the authors want to avoid.

@Datseris @slwu89 may find it interesting

3 Likes