if you try to do, julia> Base.ImmutableDict( :a => 1, :b => 2 ) you get, ERROR: MethodError: no method matching Base.ImmutableDict(::Pair{Symbol,Int64}, ::Pair{Symbol,Int64}) Closest candidates are: Base.ImmutableDict(::Pair{K,V}) where {K, V} at dict.jl:624 Base.Immu…

function Base.ImmutableDict(KV::Pair{K,V}, KVs::Pair{K,V}...) where {K,V} d = Base.ImmutableDict(KV) for p in KVs d = Base.ImmutableDict(d,p) end return d end julia> Base.ImmutableDict( :a => 1, :b => 42, :c => 404 ) ImmutableDict{Sy…

with the (undocumented!) constructor ImmutableDict{K,V}(parent::ImmutableDict, key, value) where {K,V} = new(parent, key, value) or more typically via the convenience version: d = ImmutableDict(:a => 1) d1 = ImmutableDict(d, :b => 2) (I learnt this from the test suite.)

Is there a way to combine this with: [image] Stack overflow when merging 50000 dicts New to Julia Okay, found a solution: merge!(Dict(), a...) is very fast…

In dict.jl, this: # this actually defines reverse iteration (e.g. it should not be used for merge/copy/filter type operations) start(t::ImmutableDict) = t next(::ImmutableDict{K,V}, t) where {K,V} = (Pair{K,V}(t.key, t.value), t.parent) done(::ImmutableDict, t) = !isdefined(t, :parent) is not very…

Defining this method is useful for populating an ImmutableDict from single Dict. function Base.merge!(d::Base.ImmutableDict, dsrc::Dict) for (k,v) in dsrc d = Base.ImmutableDict(d,k=>v) end return d end julia> dsrc = Dict(1=>2, 3=>4); julia> d = merge!(Base.ImmutableDict{Int,I…

ImmutableDict is immutable, thus strictly speaking merge! doesn’t apply to it. The answer to your original question was also here (found just by looking up “ImmutableDict” here, there are just 4 results): Initialising a dictionary with duplicate keys - #3 by giordano

Yes, you are right. If you do merge!(d1,d2), then d1 will still be bound to the same unchanged object. So the name merge! is incorrect. The method in the post you link is a solution for the (minimal) example given in the original question— but only for exactly two entries. In any case, I think th…

[image] giordano: ImmutableDict is immutable, thus strictly speaking merge! doesn’t apply to it. This is true, but a Dict usually has more than one or two entries? [image] jlapeyre: but only for exactly two entries Can someone explain why ImmutableDict doesn’t allow construction with …

[image] djsegal: but a Dict usually has more than one or two entries? I’m not sure what are you referring to. [image] djsegal: Can someone explain why ImmutableDict doesn’t allow construction with multiple pairs to begin with? Strictly speaking there is no such thing like an Immutable…

Isn’t an ImmutableDict the immutable counterpart of a Dict? Dicts usually have multiple keys (or you would just make them into a variable)? By example, Base.ImmutableDict( :a => 1, :b => 42, :c => 404 ) is how I would usually use a Dict. Not just: Base.ImmutableDict( :a => 1 …

Isn’t an ImmutableDict the immutable counterpart of a Dict? Yes. From the documentation: ImmutableDict is a Dictionary implemented as an immutable linked list. The implementation is a particular singly-linked list. Each node has three fields, a key, a value, and a link to the parent node. The…

Way to construct multi-key ImmutableDict

General Usage

djsegal April 12, 2018, 4:22am 3

Is there a way to combine this with:

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Way to construct multi-key ImmutableDict

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