DynamicStructs

DynamicStructs is a Julia package that allows you to create structs with dynamic properties. These properties behave similarly to fields of type Any in mutable structs, but are bound to the instance rather than the type, and can be added and deleted at runtime.

Install from the REPL with ]add DynamicStructs.

using DynamicStructs

@dynamic struct Spaceship
    name::String
end

ship = Spaceship("Hail Mary", crew=["Grace", "Yao", "Ilyukhina"])

ship.name # "Hail Mary"
ship.crew # ["Grace", "Yao", "Ilyukhina"]

ship.crew = ["Grace"] # reassign crew
ship.fuel = 20906.0 # assign fuel

ship.crew # ["Grace"]
ship.fuel # 20906.0

hasproperty(ship, :fuel) # true
delete!(ship, :fuel) # delete fuel
hasproperty(ship, :fuel) # false
ship.fuel # ERROR: Spaceship instance has no field or property fuel

• Create structs with both fields and dynamic properties using the @dynamic macro.
• Use mutable struct to allow for modifying field values.
• Type safety for fields.
• Add, modify, and delete dynamic properties at runtime.
• Check if types and instances are dynamic with isdynamictype and isdynamic:

julia> (isdynamictype(Spaceship), isdynamic(ship), isdynamic(Spaceship))
(true, true, false)

• Get a tuple of the current dynamic properties with getproperties(ship; fields=false):

julia> getproperties(ship; fields=false)
(:crew,)

• Custom show method for pretty-printing (generalized to work with any type using show_fields_properties(io, x)):

julia> ship
Spaceship:
  1 field:
    name::String = "Hail Mary"
  1 property:
    crew::Vector{String} = ["Grace"]

• DynamicObjects.jl
• PropertyDicts.jl
• ProtoStructs.jl