Commuting Macros (#16)

Author: janneshb

Project.toml

@@ -1,7 +1,7 @@
 name = "ConcreteStructs"
 uuid = "2569d6c7-a4a2-43d3-a901-331e8e4be471"
 authors = ["Jonnie Diegelman <jonniediegelman@gmail.com> and contributors"]
-version = "0.2.4"
+version = "0.2.5"
 
 [compat]
 julia = "1.1"

src/ConcreteStructs.jl

@@ -102,8 +102,8 @@ end
 
 # Parse whole struct definition for the @concrete macro
 function _concretize(expr)
-    expr isa Expr && expr.head == :struct || error("Invalid usage of @concrete")
-    
+    original_expr, expr = _find_struct_def(expr)
+
     is_mutable = expr.args[1]
     struct_name, type_params, super = _parse_head(expr.args[2])
     line_tuples = _parse_line.(expr.args[3].args)
@@ -121,6 +121,8 @@ function _concretize(expr)
     body = Expr(:block, lines..., constructor_expr)
     struct_expr = Expr(:struct, is_mutable, head, body)
 
+    struct_expr = _apply_original_expr(original_expr, struct_expr)
+
     return struct_expr, struct_name, type_params
 end
 
@@ -239,5 +241,27 @@ function _parse_line(line::Symbol)
     return (:($line::$T), T)
 end
 
+# find the struct def in case its encapsuled in other macros
+# returns full_original_expression, struct_definition_expr
+function _find_struct_def(expr; tl_expr = expr)
+    if expr.head == :struct
+        return tl_expr, expr
+    elseif expr.head == :macrocall
+        return _find_struct_def(expr.args[3]; tl_expr = tl_expr)
+    end
+    return nerror("Invalid usage of @concrete.")
+end
+
+# finds where the struct is defined in original_expr and plugs in struct_expr
+function _apply_original_expr(original_expr, struct_expr)
+    if original_expr.head == :struct
+        original_expr.args = struct_expr.args
+    elseif original_expr.head == :macrocall
+        original_expr.args[3] = _apply_original_expr(original_expr.args[3], struct_expr)
+    else
+        error("Unsupported expression.")
+    end
+    return original_expr
+end
 
 end

test/runtests.jl

@@ -201,3 +201,37 @@ end
 
     @test typeof(foo) === Foo{Int, Float64, Adjoint{Int, Vector{Int}}}
 end
+
+
+@testset "Commutation with other Macros" begin
+    # this has been working for a while already
+    Base.@kwdef @concrete struct Foo2{T<:Real}
+        x::T = 1.0
+        y = true
+        z = 42
+    end
+
+    foo = Foo2()
+    @test typeof(foo) === Foo2{Float64, Bool, Int64}
+
+    # this is new
+    @concrete Base.@kwdef struct Foo3{T<:Real}
+        x::T = 1.0
+        y = true
+        z = 42
+    end
+
+    foo = Foo3()
+    @test typeof(foo) === Foo3{Float64, Bool, Int64}
+
+    foo = Foo3(z=[1, 2, 3])
+    @test typeof(foo) === Foo3{Float64, Bool, Vector{Int64}}
+
+    # terse test case, unfortunately doesn't work the other way around. But also never did.
+    @concrete terse Base.@kwdef struct TerseKWDef
+        a = 1.0
+        b = true
+    end
+    terse_kw_def = TerseKWDef(b = false)
+    @test typeof(terse_kw_def) === TerseKWDef{Float64, Bool}
+end