Trying to get exaples to map to their given values

src/spectator/dsl/structure_dsl.cr

@@ -30,8 +30,41 @@ module Spectator
         module Given%given
           include {{@type.id}}
 
+          def %collection
+            {{collection}}
+          end
+
+          def %first
+            %collection.first
+          end
+
+          def %group
+            ::Spectator::Definitions::GROUPS[\{{@type.symbolize}}].as(
+              GivenExampleGroup(typeof(%first)))
+          end
+
+          def %value
+            %group.value_for(self)
+          end
+
+          def %dup
+            if (value = %value).responds_to?(:clone)
+              value.clone
+            else
+              value.dup
+            end
+          end
+
+          @%wrapper : ValueWrapper?
+
           def {{block.args.empty? ? "value".id : block.args.first}}
-            nil # TODO
+            if (wrapper = @%wrapper)
+              wrapper.unsafe_as(TypedValueWrapper(typeof(%value))).value
+            else
+              %dup.tap do |value|
+                @%wrapper = TypedValueWrapper(typeof(%value)).new(value)
+              end
+            end
           end
 
           _given_collection Collection%collection, %to_a do

src/spectator/given_example_group.cr

@@ -2,14 +2,24 @@ require "./example_group"
 
 module Spectator
   class GivenExampleGroup(T) < ExampleGroup
+    @mapping = {} of Example => T
+
     def initialize(what, @collection : Array(T), parent = nil)
       super(what, parent)
     end
 
     protected def add_examples(array : Array(Example))
-      @collection.each do |item|
-        super(array)
-      end
+      @collection.each do |value|
+        examples = super.all_examples
+        examples.each do |example|
+          @mapping[example] = value
+        end
+        array.concat(examples)
+      end
+    end
+
+    def value_for(example : Example) : T
+      @mapping[example]
     end
   end
 end