Merge pull request #70 from SciML/as/array-observed

feat: support observed generation for array expressions

Author: ChrisRackauckas

Project.toml

@@ -6,15 +6,13 @@ version = "0.3.18"
 [deps]
 Accessors = "7d9f7c33-5ae7-4f3b-8dc6-eff91059b697"
 ArrayInterface = "4fba245c-0d91-5ea0-9b3e-6abc04ee57a9"
-MacroTools = "1914dd2f-81c6-5fcd-8719-6d5c9610ff09"
 RuntimeGeneratedFunctions = "7e49a35a-f44a-4d26-94aa-eba1b4ca6b47"
 StaticArraysCore = "1e83bf80-4336-4d27-bf5d-d5a4f845583c"
 
 [compat]
 Accessors = "0.1.36"
 Aqua = "0.8"
 ArrayInterface = "7.9"
-MacroTools = "0.5.13"
 Pkg = "1"
 RuntimeGeneratedFunctions = "0.5.12"
 SafeTestsets = "0.0.1"

src/SymbolicIndexingInterface.jl

@@ -1,6 +1,5 @@
 module SymbolicIndexingInterface
 
-import MacroTools
 using RuntimeGeneratedFunctions
 import StaticArraysCore: MArray, similar_type
 import ArrayInterface

src/symbol_cache.jl

@@ -69,44 +69,68 @@ function independent_variable_symbols(sc::SymbolCache)
 end
 is_observed(sc::SymbolCache, sym) = false
 is_observed(::SymbolCache, ::Expr) = true
+is_observed(::SymbolCache, ::AbstractArray{Expr}) = true
+is_observed(::SymbolCache, ::Tuple{Vararg{Expr}}) = true
+
+struct ExpressionSearcher
+    declared::Set{Symbol}
+    fnbody::Expr
+end
+
+ExpressionSearcher() = ExpressionSearcher(Set{Symbol}(), Expr(:block))
+
+function (exs::ExpressionSearcher)(sys, expr::Expr)
+    for arg in expr.args
+        exs(sys, arg)
+    end
+    exs(sys, expr.head)
+    return nothing
+end
+
+function (exs::ExpressionSearcher)(sys, sym::Symbol)
+    sym in exs.declared && return
+    if is_variable(sys, sym)
+        idx = variable_index(sys, sym)
+        push!(exs.fnbody.args, :($sym = u[$idx]))
+    elseif is_parameter(sys, sym)
+        idx = parameter_index(sys, sym)
+        push!(exs.fnbody.args, :($sym = p[$idx]))
+    elseif is_independent_variable(sys, sym)
+        push!(exs.fnbody.args, :($sym = t))
+    end
+    push!(exs.declared, sym)
+    return nothing
+end
+
+(::ExpressionSearcher)(sys, sym) = nothing
+
 function observed(sc::SymbolCache, expr::Expr)
     let cache = Dict{Expr, Function}()
         return get!(cache, expr) do
-            fnbody = Expr(:block)
-            declared = Set{Symbol}()
-            MacroTools.postwalk(expr) do sym
-                sym isa Symbol || return
-                sym in declared && return
-                if sc.variables !== nothing &&
-                   (idx = findfirst(isequal(sym), sc.variables)) !== nothing
-                    push!(fnbody.args, :($sym = u[$idx]))
-                    push!(declared, sym)
-                elseif sc.parameters !== nothing &&
-                       (idx = findfirst(isequal(sym), sc.parameters)) !== nothing
-                    push!(fnbody.args, :($sym = p[$idx]))
-                    push!(declared, sym)
-                elseif sym === sc.independent_variables ||
-                       sc.independent_variables isa Vector &&
-                       sym == only(sc.independent_variables)
-                    push!(fnbody.args, :($sym = t))
-                    push!(declared, sym)
-                end
-            end
+            exs = ExpressionSearcher()
+            exs(sc, expr)
             fnexpr = if is_time_dependent(sc)
                 :(function (u, p, t)
-                    $fnbody
+                    $(exs.fnbody)
                     return $expr
                 end)
             else
                 :(function (u, p)
-                    $fnbody
+                    $(exs.fnbody)
                     return $expr
                 end)
             end
             return RuntimeGeneratedFunctions.@RuntimeGeneratedFunction(fnexpr)
         end
     end
 end
+function observed(sc::SymbolCache, exprs::AbstractArray{Expr})
+    return observed(sc, :(reshape([$(exprs...)], $(size(exprs)))))
+end
+function observed(sc::SymbolCache, exprs::Tuple{Vararg{Expr}})
+    return observed(sc, :(($(exprs...),)))
+end
+
 function is_time_dependent(sc::SymbolCache)
     sc.independent_variables === nothing && return false
     if symbolic_type(sc.independent_variables) == NotSymbolic()

test/symbol_cache_test.jl

@@ -34,6 +34,17 @@ obsfn = observed(sc, :(x + a + t))
 obsfn2 = observed(sc, :(x + a + t))
 @test obsfn === obsfn2
 
+@test is_observed(sc, [:(x + a), :(a + t)])
+obsfn3 = observed(sc, [:(x + a), :(a + t)])
+@test obsfn3(ones(3), 2ones(2), 3.0) ≈ [3.0, 5.0]
+@test is_observed(sc, [:(x + a) :(y + b); :(x + y) :(a + b)])
+obsfn4 = observed(sc, [:(x + a) :(y + b); :(x + y) :(a + b)])
+@test size(obsfn4(ones(3), 2ones(2), 3.0)) == (2, 2)
+@test obsfn4(ones(3), 2ones(2), 3.0) ≈ [3.0 3.0; 2.0 4.0]
+@test is_observed(sc, (:(x + a), :(y + b)))
+obsfn5 = observed(sc, (:(x + a), :(y + b)))
+@test all(obsfn5(ones(3), 2ones(2), 3.0) .≈ (3.0, 3.0))
+
 sc = SymbolCache([:x, :y], [:a, :b])
 @test !is_time_dependent(sc)
 @test sort(all_symbols(sc)) == [:a, :b, :x, :y]