Le samedi 03 janvier 2015 à 08:29 -0800, Ismael VC a écrit :
> I'm trying to port this Python class:
>
> class Env(dict):
> "An environment: a dict of {'var':val} pairs, with an outer Env."
> def __init__(self, parms=(), args=(), outer=None):
> self.update(zip(parms, args))
> self.outer = outer
> def find(self, var):
> "Find the innermost Env where var appears."
> return self if (var in self) else self.outer.find(var)
>
> Haven't even got to the `find` method yet! :( ...this is what I've
> done:
>
> Environment type:
>
> julia> type Env
>
> data::Dict
>
> outer::Nullable{Env}
>
> Env() = new(Dict(), Nullable{Env}())
>
> end
>
>
> Outer constructor:
>
> julia> function Env(parms::Tuple, args::Tuple, outer::Env)
>
> Env(Dict(zip(parms, args)), Nullable(outer))
>
> end
>
> Env
>
>
> So far so good:
>
> julia> parms = (:foo, :bar, :baz);
>
>
>
> julia> args = (1, 2, 3);
>
>
>
> julia> outer = Env()
>
> Env(Dict{Any,Any}(),Nullable{Env}())
>
>
> I've spent a lot of time trying to understand this, without success:
>
> julia> inner = Env(parms, args, outer)
>
> ERROR: `convert` has no method matching
> convert(::Type{Env}, ::(Symbol,Symbol,Symbol), ::(Int32,Int32,Int32), ::Env)
>
> in call at base.jl:35
>
>
> I'll have to go to work before soon, I know this'll be itching my head
> all day long! :P
>
> What am I doing wrong? or How many things am I doing wrong? :O
This is the error I get with lastest master:
julia> inner = Env(parms, args, outer)
ERROR: `convert` has no method matching
convert(::Type{Env}, ::Dict{Symbol,Int64}, ::Nullable{Env})
in call at none:2
Actually the error comes from the second call to Env():
Env(Dict(zip(parms, args)), Nullable(outer))
I think this is because you have overridden the inner constructor
without providing a two-argument version. It works if you move it to an
outer constructor:
type Env
data::Dict
outer::Nullable{Env}
end
Env() = Env(Dict(), Nullable{Env}())
function Env(parms::Tuple, args::Tuple, outer::Env)
Env(Dict(zip(parms, args)), Nullable(outer))
end
Regards
