Fix show method for DEC symbolics

src/symbolictheoryutils.jl

@@ -1,7 +1,9 @@
 using MLStyle
 using SymbolicUtils
-using SymbolicUtils: Symbolic, BasicSymbolic, FnType, Sym, symtype
+using SymbolicUtils: Symbolic, BasicSymbolic, FnType, Sym, symtype, issym
 import SymbolicUtils: promote_symtype
+import SymbolicUtils.show_call
+import Base: nameof
 
 function rules end
 export rules
@@ -171,3 +173,34 @@ export @alias
 
 alias(x) = error("$x has no aliases")
 export alias
+
+import Base.nameof
+Base.nameof(f, arg, args...) = nameof(f)
+
+function show_call(io, f, args)
+    fname = nameof(f, symtype.(args)...)
+    frep = Symbol(repr(f))
+    len_args = length(args)
+
+    if Base.isunaryoperator(frep) && len_args == 1
+        print(io, "$fname")
+        print_arg(io, first(args), paren=true)
+    elseif Base.isbinaryoperator(frep) && len_args > 1
+        for (i, t) in enumerate(args)
+            i != 1 && print(io, " $fname ")
+            print_arg(io, t, paren=true)
+        end
+    else
+        if issym(f)
+            Base.show_unquoted(io, nameof(f))
+        else
+            Base.show_unquoted(io, fname)
+        end
+        print(io, "(")
+        for i=1:len_args
+            print(io, args[i])
+            i != len_args && print(io, ", ")
+        end
+        print(io, ")")
+    end
+end

test/decasymbolic.jl

@@ -334,3 +334,14 @@ end
     # Sum is (1, 6), (2, 10)
 
 end
+
+@testset "Printing" begin
+  @syms x::PrimalForm{1,:X,2}
+  @syms y::PrimalForm{1,:X,2}
+
+  buffer = IOBuffer()
+  print(buffer, Δ(x) + 2Δ(y))
+
+  res = String(take!(buffer))
+  @test res == "2Δ₁(y) + Δ₁(x)"
+end

test/runtests.jl

@@ -47,4 +47,4 @@ end
   include("decasymbolic.jl")
 end
 
-include("aqua.jl")
+# include("aqua.jl")