trying to use symbolicutils export from #64

src/ThDEC.jl

@@ -26,7 +26,7 @@ export SpaceLookup
 
 SpaceLookup(default::Space) = SpaceLookup(default, Dict{Symbol, Space}(nameof(default) => default))
 
-@data Sort begin
+@data Sort <: Number begin
     Scalar()
     Form(dim::Int, isdual::Bool, space::Space)
     VField(isdual::Bool, space::Space)

src/decasymbolic.jl

@@ -87,13 +87,17 @@ Number(v::VField) = VFieldT{isdual(v), nameof(space(v)), dim(space(v))}
 
 # for every unary operator in our theory, take a BasicSymbolic type, convert its type parameter to a Sort in our theory, and return a term
 unop_dec = [:∂ₜ, :d, :★, :♯, :♭, :-]
+# $unop(x) = FnType(unop, args)
 for unop in unop_dec
     @eval begin
         @nospecialize
         function ThDEC.$unop(
             v::BasicSymbolic{T}
         ) where {T<:DECType}
+            # convert the DECType to ThDEC to type check
             s = ThDEC.$unop(Sort(T))
+            # the resulting type is converted back to DECType
+            # the resulting term has the operation has its head and `v` as its args.
             SymbolicUtils.Term{Number(s)}(ThDEC.$unop, [v])
         end
     end

test/klausmeier.jl

@@ -35,8 +35,8 @@ Phytodynamics = parse_decapode(quote
   (n,w)::Form0
   m::Constant
 
-  ∂ₜ(n) == w - m*n + Δ(n)
+  ∂ₜ(n) == w - m*n #+ Δ(n)
   # ∂ₜ(n) == w * n*n - m*n + Δ(n)
 end)
 
-DecaSymbolic(lookup, Phytodynamics)
+ps = DecaSymbolic(lookup, Phytodynamics)

test/symbolicutils.jl

@@ -0,0 +1,52 @@
+using SymbolicUtils
+import SymbolicUtils: promote_symtype, symtype
+using DiagrammaticEquations
+using DiagrammaticEquations.ThDEC
+using DiagrammaticEquations.SymbolicUtilsInterop
+import DiagrammaticEquations.SymbolicUtilsInterop: DECType
+using MLStyle
+
+# Ω₀ = Form(0, false, Space(:X,1))
+Ω₀ = FormT{0,false, :X, 1}
+Ω₁ = FormT{1,false, :X, 1}
+# @syms x f(x::Sort)::Sort
+@syms x f(x::DECType)::DECType
+@syms y::Ω₀ v::Ω₁
+
+fdim(::FormT{i,isdual,space,dim}) where {i,isdual,space,dim} = i
+isdual(::FormT{i,duality,space,dim}) where {i,duality,space,dim} = duality
+spacename(::FormT{i,isdual,X,dim}) where {i,isdual,X,dim} = X
+sdim(::FormT{i,isdual,space,dim}) where {i,isdual,space,dim} = dim
+
+fdim(::PrimalFormT{i,space,dim}) where {i,space,dim} = i
+isdual(::PrimalFormT{i,space,dim}) where {i,space,dim} = false
+spacename(::PrimalFormT{i,X,dim}) where {i,X,dim} = X
+sdim(::PrimalFormT{i,space,dim}) where {i,space,dim} = dim
+
+function SymbolicUtils.promote_symtype(f::typeof(f), ::T) where T<: DECType
+  @show "Hit me"
+  FormT{fdim(T)+1, !isdual(T), spacename(T), sdim(T)}
+end
+
+# function SymbolicUtils.promote_symtype(f::typeof(f), ::FormT{i,isdual,space,dim}) where {i,isdual,space,dim}
+#   @show "Hit me"
+#   FormT{i+1, !isdual, space, dim}
+# end
+
+# function SymbolicUtils.promote_symtype(f::typeof(f), args...) 
+#   @show args
+#   @match args[1] begin
+#     Scalar() => Scalar()
+#     FormT(&i, &isdual, &space, &dim) => FormT(i+1, isdual, space, dim)
+#     _ => error("type checking error for f")
+#   end
+# end
+
+using Test
+@test_throws Exception f(x)
+@test_throws Exception f(x)
+# @less f(y)
+symtype(f(y))
+promote_symtype(f, symtype(y))
+@syms x f(x::DECType)
+promote_symtype(f, symtype(y))