Merge pull request #175 from MilesCranmer/dev

Fix `@mlj_model` parsing bug

Author: ablaom

src/model_def.jl

@@ -62,12 +62,12 @@ function _process_model_def(modl, ex)
             if line.head == :(=) # assignment for default
                 default = line.args[2]
                 # if a constraint is given (value::constraint)
-                if default isa Expr && length(default.args) > 1
+                if default isa Expr && default.head == :(::)
                     constraints[param] = default.args[2]
                     # now discard the constraint to keep only the value
                     default = default.args[1]
                 end
-                defaults[param] = default # this will be a value not an expr
+                defaults[param] = default
 
                 # name or name::Type (for the constructor)
                 ex.args[3].args[i] = line.args[1] 

test/model_def.jl

@@ -151,3 +151,34 @@ end
     @test Cc().a === nothing
     @test Cd().a === missing
 end
+
+@testset "Expression defaults" begin
+    # Should work with and without constraint:
+    @mlj_model mutable struct Foo1
+        a::Vector{Int} = [1, 2, 3]
+    end
+    @test Foo1().a == [1, 2, 3]
+    @mlj_model mutable struct Foo2
+        a::Vector{Int} = [1, 2, 3]::(true)
+    end
+    @test Foo2().a == [1, 2, 3]
+
+    # Constraints applied
+    @mlj_model mutable struct Foo3
+        a::Vector{Int} = [1, 2, 3]::(all(>(0), _))
+    end
+    @test redirect_stderr(devnull) do
+        Foo3(; a = [-1]).a == [1, 2, 3]
+    end
+
+    # Negative number:
+    @mlj_model mutable struct Foo4
+        a::Float64 = -1.0
+    end
+    @test Foo4().a === -1.0
+    @mlj_model mutable struct Foo5
+        a::Float64 = (-1.0)::(true)
+    end
+    @test Foo5().a == -1.0
+
+end