Add Crystal::Repl::Value#runtime_type (#14156)

Co-authored-by: Sijawusz Pur Rahnama <sija@sija.pl>

spec/compiler/crystal/tools/repl_spec.cr

@@ -17,4 +17,53 @@ describe Crystal::Repl do
     success_value(repl.parse_and_interpret("def foo; 1 + 2; end")).value.should eq(nil)
     success_value(repl.parse_and_interpret("foo")).value.should eq(3)
   end
+
+  describe "can return static and runtime type information for" do
+    it "Non Union" do
+      repl = Crystal::Repl.new
+      repl.prelude = "primitives"
+      repl.load_prelude
+
+      repl_value = success_value(repl.parse_and_interpret("1"))
+      repl_value.type.to_s.should eq("Int32")
+      repl_value.runtime_type.to_s.should eq("Int32")
+    end
+
+    it "MixedUnionType" do
+      repl = Crystal::Repl.new
+      repl.prelude = "primitives"
+      repl.load_prelude
+
+      repl_value = success_value(repl.parse_and_interpret("1 || \"a\""))
+      repl_value.type.to_s.should eq("(Int32 | String)")
+      repl_value.runtime_type.to_s.should eq("Int32")
+    end
+
+    it "UnionType" do
+      repl = Crystal::Repl.new
+      repl.prelude = "primitives"
+      repl.load_prelude
+
+      repl_value = success_value(repl.parse_and_interpret("true || 1"))
+      repl_value.type.to_s.should eq("(Bool | Int32)")
+      repl_value.runtime_type.to_s.should eq("Bool")
+    end
+
+    it "VirtualType" do
+      repl = Crystal::Repl.new
+      repl.prelude = "primitives"
+      repl.load_prelude
+
+      repl.parse_and_interpret <<-CRYSTAL
+        class Foo
+        end
+
+        class Bar < Foo
+        end
+      CRYSTAL
+      repl_value = success_value(repl.parse_and_interpret("Bar.new || Foo.new"))
+      repl_value.type.to_s.should eq("Foo+") # Maybe should Foo to match typeof
+      repl_value.runtime_type.to_s.should eq("Bar")
+    end
+  end
 end

src/compiler/crystal/interpreter/primitives.cr

@@ -87,6 +87,8 @@ class Crystal::Repl::Compiler
 
       pointer_add(inner_sizeof_type(element_type), node: node)
     when "class"
+      # Should match Crystal::Repl::Value#runtime_type
+      # in src/compiler/crystal/interpreter/value.cr
       obj = obj.not_nil!
       type = obj.type.remove_indirection
 

src/compiler/crystal/interpreter/value.cr

@@ -67,6 +67,21 @@ struct Crystal::Repl::Value
     end
   end
 
+  def runtime_type : Crystal::Type
+    # Should match Crystal::Repl::Compiler#visit_primitive "class" case
+    # in src/compiler/crystal/interpreter/primitives.cr
+    case type
+    when Crystal::UnionType
+      type_id = @pointer.as(Int32*).value
+      context.type_from_id(type_id)
+    when Crystal::VirtualType
+      type_id = @pointer.as(Void**).value.as(Int32*).value
+      context.type_from_id(type_id)
+    else
+      type
+    end
+  end
+
   # Copies the contents of this value to another pointer.
   def copy_to(pointer : Pointer(UInt8))
     @pointer.copy_to(pointer, context.inner_sizeof_type(@type))