Skip to content

feat: add ExpandDerivativeDict #4652

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
AayushSabharwal merged 1 commit into from
Jun 22, 2026
Merged

feat: add ExpandDerivativeDict #4652

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
102 changes: 66 additions & 36 deletions lib/ModelingToolkitBase/src/derivative_dict.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -12,51 +12,81 @@ struct DerivativeDict{K, D <: AbstractDict{K, SymbolicT}} <: AbstractDict{K, Sym
dict::D
end

DerivativeDict() = DerivativeDict(Dict{SymbolicT, SymbolicT}())
DerivativeDict(args::Pair...) = DerivativeDict(Dict(args...))
DerivativeDict{K}(args...) where {K} = DerivativeDict(Dict{K, SymbolicT}(args...))
"""
$(TYPEDEF)

Base.copy(dd::DerivativeDict) = DerivativeDict(copy(dd.dict))
function Base.empty(dd::DerivativeDict, ::Type{K}, ::Type{V}) where {K, V}
return DerivativeDict(empty(dd.dict, K, V))
Identical to `DerivativeDict`, but `Differential(t, n)(x)` maps to
`expand_derivatives(Differential(t, n-1)(v))`. Mutates the wrapped dictionary in `get`
for efficiency - the `expand_derivatives` result is cached. This also means that `getindex`
mutates.
"""
struct ExpandDerivativeDict{K, D <: AbstractDict{K, SymbolicT}} <: AbstractDict{K, SymbolicT}
dict::D
end

struct __DDSentinel end
const DD_SENTINEL = __DDSentinel()

function Base.get(def::Base.Callable, dd::DerivativeDict, k::SymbolicT)
res = get(dd.dict, k, DD_SENTINEL)
res === DD_SENTINEL || return res
return Moshi.Match.@match k begin
BSImpl.Term(; f, args) && if f isa Differential && f.order::Int > 1 end => begin
order = f.order::Int
res = get(dd.dict, Differential(f.x, 1)(args[1]), DD_SENTINEL)
res === DD_SENTINEL && return def()
res = res::SymbolicT
return Differential(f.x, order - 1)(res)
for T in [:DerivativeDict, :ExpandDerivativeDict]
@eval begin
$T() = $T(Dict{SymbolicT, SymbolicT}())
$T(args::Pair...) = $T(Dict(args...))
$T{K}(args...) where {K} = $T(Dict{K, SymbolicT}(args...))

Base.copy(dd::$T) = $T(copy(dd.dict))
function Base.empty(dd::$T, ::Type{K}, ::Type{V}) where {K, V}
return $T(empty(dd.dict, K, V))
end
_ => return def()
end
end
function Base.get(f::Base.Callable, dd::DerivativeDict, k::Union{Num, Arr, CallAndWrap})
return get(f, dd, unwrap(k))
end
Base.get(f::Base.Callable, dd::DerivativeDict, k) = get(f, dd.dict, k)

Base.get(dd::DerivativeDict, k, default) = get(Returns(default), dd, k)
Base.haskey(dd::$T, k) = get(Returns(DD_SENTINEL), dd, k) !== DD_SENTINEL

Base.haskey(dd::DerivativeDict, k) = get(Returns(DD_SENTINEL), dd, k) !== DD_SENTINEL
Base.setindex!(dd::$T, v, k) = setindex!(dd.dict, unwrap(v), unwrap(k))

function Base.getindex(dd::DerivativeDict, k)
res = get(Returns(DD_SENTINEL), dd, k)
res === DD_SENTINEL && throw(KeyError(k))
return res::SymbolicT
end
Base.isempty(dd::$T) = isempty(dd.dict)
Base.length(dd::$T) = length(dd.dict)
Base.iterate(dd::$T, args...) = Base.iterate(dd.dict, args...)
Base.sizehint!(dd::$T, n; kw...) = sizehint!(dd.dict, n; kw...)
Base.empty!(dd::$T) = empty!(dd.dict)

Base.setindex!(dd::DerivativeDict, v, k) = setindex!(dd.dict, unwrap(v), unwrap(k))
function Base.get(def::Base.Callable, dd::$T, k::SymbolicT)
res = get(dd.dict, k, DD_SENTINEL)
res === DD_SENTINEL || return res
return Moshi.Match.@match k begin
BSImpl.Term(; f, args) && if f isa Differential && f.order::Int > 1 end => begin
order = f.order::Int
res = get(dd.dict, Differential(f.x, 1)(args[1]), DD_SENTINEL)
res === DD_SENTINEL && return def()
res = res::SymbolicT
$(
if T === :DerivativeDict
:(return Differential(f.x, order - 1)(res))
elseif T === :ExpandDerivativeDict
quote
res = expand_derivatives(Differential(f.x, order - 1)(res))
dd.dict[k] = res
return res
end
else
error("Not handled")
end
)
end
_ => return def()
end
end
function Base.get(f::Base.Callable, dd::$T, k::Union{Num, Arr, CallAndWrap})
return get(f, dd, unwrap(k))
end
Base.get(f::Base.Callable, dd::$T, k) = get(f, dd.dict, k)

Base.get(dd::$T, k, default) = get(Returns(default), dd, k)

function Base.getindex(dd::$T, k)
res = get(Returns(DD_SENTINEL), dd, k)
res === DD_SENTINEL && throw(KeyError(k))
return res::SymbolicT
end

end
end

Base.isempty(dd::DerivativeDict) = isempty(dd.dict)
Base.length(dd::DerivativeDict) = length(dd.dict)
Base.iterate(dd::DerivativeDict, args...) = Base.iterate(dd.dict, args...)
Base.sizehint!(dd::DerivativeDict, n; kw...) = sizehint!(dd.dict, n; kw...)
Base.empty!(dd::DerivativeDict) = empty!(dd.dict)
Loading