Merge pull request #82 from SymbolicML/parametric-expressions2

Improve ParametricExpressions

Author: MilesCranmer

Project.toml

@@ -1,7 +1,7 @@
 name = "DynamicExpressions"
 uuid = "a40a106e-89c9-4ca8-8020-a735e8728b6b"
 authors = ["MilesCranmer <miles.cranmer@gmail.com>"]
-version = "0.18.0-alpha.1"
+version = "0.18.0"
 
 [deps]
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"

src/DynamicExpressions.jl

@@ -66,7 +66,8 @@ import .NodeModule:
 @reexport import .EvaluationHelpersModule
 @reexport import .ExtensionInterfaceModule: node_to_symbolic, symbolic_to_node
 @reexport import .RandomModule: NodeSampler
-@reexport import .ExpressionModule: AbstractExpression, Expression, with_tree
+@reexport import .ExpressionModule:
+    AbstractExpression, Expression, with_contents, with_metadata, get_contents, get_metadata
 import .ExpressionModule:
     get_tree, get_operators, get_variable_names, Metadata, default_node_type, node_type
 @reexport import .ParseModule: @parse_expression, parse_expression

src/Expression.jl

@@ -6,6 +6,7 @@ using ..NodeModule: AbstractExpressionNode, Node
 using ..OperatorEnumModule: AbstractOperatorEnum, OperatorEnum
 using ..UtilsModule: Undefined
 
+import ..NodeModule: copy_node, set_node!, count_nodes, tree_mapreduce, constructorof
 import ..NodeUtilsModule:
     preserve_sharing,
     count_constants,
@@ -85,7 +86,7 @@ end
 end
 
 node_type(::Union{E,Type{E}}) where {N,E<:AbstractExpression{<:Any,N}} = N
-@unstable default_node_type(::Type{<:AbstractExpression}) = Node
+@unstable default_node_type(_) = Node
 default_node_type(::Type{<:AbstractExpression{T}}) where {T} = Node{T}
 
 ########################################################
@@ -128,28 +129,52 @@ end
 function Base.copy(ex::AbstractExpression; break_sharing::Val=Val(false))
     return error("`copy` function must be implemented for $(typeof(ex)) types.")
 end
-function Base.hash(ex::AbstractExpression, h::UInt)
-    return error("`hash` function must be implemented for $(typeof(ex)) types.")
-end
-function Base.:(==)(x::AbstractExpression, y::AbstractExpression)
-    return error("`==` function must be implemented for $(typeof(x)) types.")
-end
 function get_constants(ex::AbstractExpression)
     return error("`get_constants` function must be implemented for $(typeof(ex)) types.")
 end
 function set_constants!(ex::AbstractExpression{T}, constants, refs) where {T}
     return error("`set_constants!` function must be implemented for $(typeof(ex)) types.")
 end
+function get_contents(ex::AbstractExpression)
+    return error("`get_contents` function must be implemented for $(typeof(ex)) types.")
+end
+function get_metadata(ex::AbstractExpression)
+    return error("`get_metadata` function must be implemented for $(typeof(ex)) types.")
+end
 ########################################################
 
 """
-    with_tree(ex::AbstractExpression, tree::AbstractExpressionNode)
+    with_contents(ex::AbstractExpression, tree::AbstractExpressionNode)
+    with_contents(ex::AbstractExpression, tree::AbstractExpression)
 
 Create a new expression based on `ex` but with a different `tree`
 """
-function with_tree(ex::AbstractExpression, tree)
-    return constructorof(typeof(ex))(tree, ex.metadata)
+function with_contents(ex::AbstractExpression, tree::AbstractExpression)
+    return with_contents(ex, get_contents(tree))
+end
+function with_contents(ex::AbstractExpression, tree)
+    return constructorof(typeof(ex))(tree, get_metadata(ex))
+end
+function get_contents(ex::Expression)
+    return ex.tree
+end
+
+"""
+    with_metadata(ex::AbstractExpression, metadata)
+    with_metadata(ex::AbstractExpression; metadata...)
+
+Create a new expression based on `ex` but with a different `metadata`.
+"""
+function with_metadata(ex::AbstractExpression; metadata...)
+    return with_metadata(ex, Metadata((; metadata...)))
+end
+function with_metadata(ex::AbstractExpression, metadata::Metadata)
+    return constructorof(typeof(ex))(get_contents(ex), metadata)
+end
+function get_metadata(ex::Expression)
+    return ex.metadata
 end
+
 function preserve_sharing(::Union{E,Type{E}}) where {T,N,E<:AbstractExpression{T,N}}
     return preserve_sharing(N)
 end
@@ -169,25 +194,17 @@ end
 function Base.copy(ex::Expression; break_sharing::Val=Val(false))
     return Expression(copy(ex.tree; break_sharing), copy(ex.metadata))
 end
-function Base.hash(ex::Expression, h::UInt)
-    return hash(ex.tree, hash(ex.metadata, h))
+function Base.hash(ex::AbstractExpression, h::UInt)
+    return hash(get_contents(ex), hash(get_metadata(ex), h))
 end
-
-"""
-    Base.:(==)(x::Expression, y::Expression)
-
-Check equality of two expressions `x` and `y` by comparing their trees and metadata.
-"""
-function Base.:(==)(x::Expression, y::Expression)
-    return x.tree == y.tree && x.metadata == y.metadata
+function Base.:(==)(x::AbstractExpression, y::AbstractExpression)
+    return get_contents(x) == get_contents(y) && get_metadata(x) == get_metadata(y)
 end
 
 # Overload all methods on AbstractExpressionNode that return an aggregation, or can
 # return an entire tree. Methods that only return the nodes are *not* overloaded, so
 # that the user must use the low-level interface.
 
-import ..NodeModule: copy_node, set_node!, count_nodes, tree_mapreduce, constructorof
-
 #! format: off
 @unstable constructorof(::Type{E}) where {E<:AbstractExpression} = Base.typename(E).wrapper
 @unstable constructorof(::Type{<:Expression}) = Expression

src/Interfaces.jl

@@ -43,7 +43,10 @@ using ..ExpressionModule:
     get_tree,
     get_operators,
     get_variable_names,
-    with_tree,
+    get_contents,
+    get_metadata,
+    with_contents,
+    with_metadata,
     default_node_type
 using ..ParametricExpressionModule: ParametricExpression, ParametricNode
 
@@ -52,6 +55,14 @@ using ..ParametricExpressionModule: ParametricExpression, ParametricNode
 ###############################################################################
 
 ## mandatory
+function _check_get_contents(ex::AbstractExpression)
+    new_ex = with_contents(ex, get_contents(ex))
+    return new_ex == ex && new_ex isa typeof(ex)
+end
+function _check_get_metadata(ex::AbstractExpression)
+    new_ex = with_metadata(ex, get_metadata(ex))
+    return new_ex == ex && new_ex isa typeof(ex)
+end
 function _check_get_tree(ex::AbstractExpression{T,N}) where {T,N}
     return get_tree(ex) isa N
 end
@@ -67,6 +78,15 @@ function _check_copy(ex::AbstractExpression)
     # TODO: Could include checks for aliasing here
     return preserves
 end
+function _check_with_contents(ex::AbstractExpression)
+    new_ex = with_contents(ex, get_contents(ex))
+    new_ex2 = with_contents(ex, ex)
+    return new_ex == ex && new_ex isa typeof(ex) && new_ex2 == ex && new_ex2 isa typeof(ex)
+end
+function _check_with_metadata(ex::AbstractExpression)
+    new_ex = with_metadata(ex, get_metadata(ex))
+    return new_ex == ex && new_ex isa typeof(ex)
+end
 
 ## optional
 function _check_count_nodes(ex::AbstractExpression)
@@ -116,10 +136,14 @@ end
 #! format: off
 ei_components = (
     mandatory = (
+        get_contents = "extracts the runtime contents of an expression" => _check_get_contents,
+        get_metadata = "extracts the runtime metadata of an expression" => _check_get_metadata,
         get_tree = "extracts the expression tree from [`AbstractExpression`](@ref)" => _check_get_tree,
         get_operators = "returns the operators used in the expression (or pass `operators` explicitly to override)" => _check_get_operators,
         get_variable_names = "returns the variable names used in the expression (or pass `variable_names` explicitly to override)" => _check_get_variable_names,
         copy = "returns a copy of the expression" => _check_copy,
+        with_contents = "returns the expression with different tree" => _check_with_contents,
+        with_metadata = "returns the expression with different metadata" => _check_with_metadata,
     ),
     optional = (
         count_nodes = "counts the number of nodes in the expression tree" => _check_count_nodes,

src/ParametricExpression.jl

@@ -19,7 +19,13 @@ import ..EvaluateModule: eval_tree_array
 import ..EvaluateDerivativeModule: eval_grad_tree_array
 import ..EvaluationHelpersModule: _grad_evaluator
 import ..ExpressionModule:
-    get_tree, get_operators, get_variable_names, max_feature, default_node_type
+    get_contents,
+    get_metadata,
+    get_tree,
+    get_operators,
+    get_variable_names,
+    max_feature,
+    default_node_type
 import ..ParseModule: parse_leaf
 
 """A type of expression node that also stores a parameter index"""
@@ -48,9 +54,13 @@ end
 """
     ParametricExpression{T,N<:ParametricNode{T},D<:NamedTuple} <: AbstractExpression{T,N}
 
-An expression to store parameters for a tree
+(Experimental) An expression to store parameters for a tree
 """
-struct ParametricExpression{T,N<:ParametricNode{T},D<:NamedTuple} <: AbstractExpression{T,N}
+struct ParametricExpression{
+    T,
+    N<:ParametricNode{T},
+    D<:NamedTuple{(:operators, :variable_names, :parameters, :parameter_names)},
+} <: AbstractExpression{T,N}
     tree::N
     metadata::Metadata{D}
 
@@ -65,8 +75,9 @@ function ParametricExpression(
     parameters::AbstractMatrix{T2},
     parameter_names,
 ) where {T1,T2}
-    @assert (isempty(parameters) && isnothing(parameter_names)) ||
-        size(parameters, 1) == length(parameter_names)
+    if !isnothing(parameter_names)
+        @assert size(parameters, 1) == length(parameter_names)
+    end
     T = promote_type(T1, T2)
     t = T === T1 ? tree : convert(ParametricNode{T}, tree)
     m = Metadata((;
@@ -127,9 +138,9 @@ end
 ###############################################################################
 # Abstract expression interface ###############################################
 ###############################################################################
-function get_tree(ex::ParametricExpression)
-    return ex.tree
-end
+get_contents(ex::ParametricExpression) = ex.tree
+get_metadata(ex::ParametricExpression) = ex.metadata
+get_tree(ex::ParametricExpression) = ex.tree
 function get_operators(ex::ParametricExpression, operators=nothing)
     return operators === nothing ? ex.metadata.operators : operators
 end
@@ -147,12 +158,6 @@ function Base.copy(ex::ParametricExpression; break_sharing::Val=Val(false))
         parameter_names=_copy_with_nothing(ex.metadata.parameter_names),
     )
 end
-function Base.hash(ex::ParametricExpression, h::UInt)
-    return hash(ex.tree, hash(ex.metadata, h))
-end
-function Base.:(==)(x::ParametricExpression, y::ParametricExpression)
-    return x.tree == y.tree && x.metadata == y.metadata
-end
 ###############################################################################
 
 ###############################################################################
@@ -283,10 +288,16 @@ function string_tree(
             UInt16(0)
         end
     end
+    _parameter_names = ex.metadata.parameter_names
+    parameter_names = if _parameter_names === nothing
+        ["p$(i)" for i in 1:num_params]
+    else
+        _parameter_names
+    end
     variable_names3 = if variable_names2 === nothing
-        vcat(["p$(i)" for i in 1:num_params], ["x$(i)" for i in 1:max_feature])
+        vcat(parameter_names, ["x$(i)" for i in 1:max_feature])
     else
-        vcat(ex.metadata.parameter_names, variable_names2)
+        vcat(parameter_names, variable_names2)
     end
     @assert length(variable_names3) >= num_params + max_feature
     return string_tree(

test/test_expressions.jl

@@ -168,14 +168,14 @@ end
     @test has_constants(ex) == false
 end
 
-@testitem "Expression with_tree" begin
+@testitem "Expression with_contents" begin
     using DynamicExpressions
 
     ex = @parse_expression(x1 + 1.5, binary_operators = [+, *], variable_names = ["x1"])
     ex2 = @parse_expression(x1 + 3.0, binary_operators = [+], variable_names = ["x1"])
 
-    t2 = DynamicExpressions.get_tree(ex2)
-    ex_modified = DynamicExpressions.with_tree(ex, t2)
+    t2 = DynamicExpressions.get_contents(ex2)
+    ex_modified = DynamicExpressions.with_contents(ex, t2)
     @test DynamicExpressions.get_tree(ex_modified) == t2
 end
 

test/test_multi_expression.jl

@@ -10,6 +10,13 @@
         trees::TREES
         metadata::Metadata{D}
 
+        function MultiScalarExpression(trees::NamedTuple, metadata::Metadata{D}) where {D}
+            example_tree = first(values(trees))
+            N = typeof(example_tree)
+            T = eltype(example_tree)
+            return new{T,N,typeof(trees),D}(trees, metadata)
+        end
+
         """
         Create a multi-expression expression type.
 
@@ -54,8 +61,6 @@
         )
         @test_throws "`get_tree` function must be implemented for" DE.get_tree(multi_ex)
         @test_throws "`copy` function must be implemented for" copy(multi_ex)
-        @test_throws "`hash` function must be implemented for" hash(multi_ex, UInt(0))
-        @test_throws "`==` function must be implemented for" multi_ex == multi_ex
         @test_throws "`get_constants` function must be implemented for" get_constants(
             multi_ex
         )
@@ -65,6 +70,12 @@
     end
 
     tree_factory(f::F, trees) where {F} = f(; trees...)
+    function DE.get_contents(ex::MultiScalarExpression)
+        return ex.trees
+    end
+    function DE.get_metadata(ex::MultiScalarExpression)
+        return ex.metadata
+    end
     function DE.get_tree(ex::MultiScalarExpression{T,N}) where {T,N}
         fused_expression = parse_expression(
             tree_factory(ex.metadata.tree_factory, ex.trees)::Expr;