Adjust product_selector print format

phlex/core/product_selector.cpp

@@ -71,10 +71,23 @@ namespace phlex {
 
   std::string product_selector::to_string() const
   {
-    if (suffix) {
-      return fmt::format("{}/{} ϵ {}", creator, *suffix, layer);
-    }
-    return fmt::format("{} ϵ {}", creator, layer);
+    // Will generate <<suffix>::<concept> by <creator> (of <stage>) in <layer>>
+    using experimental::identifier;
+    std::string_view suffix_str =
+      suffix.transform(&identifier::operator std::string_view).value_or("[ANY]");
+    std::string type_str = this->type.valid() ? fmt::format("<{}>", this->type)
+                                              : "[UNSET TYPE]"; // will later be concept
+    auto layer_str = std::string_view(layer);
+    std::string_view creator_str = creator ? std::string_view(*creator) : "[ANY]";
+    std::string_view stage_str =
+      stage.transform(&identifier::operator std::string_view).value_or("[ANY]");
+
+    return fmt::format("<suffix {} (of type {}) by creator {} (of stage {}) in layer {}>",
+                       suffix_str,
+                       type_str,
+                       creator_str,
+                       stage_str,
+                       layer_str);
   }
 
   bool product_selector::operator==(product_selector const& rhs) const

phlex/core/product_selector.hpp

@@ -69,6 +69,7 @@ namespace phlex {
 
       // NOLINTNEXTLINE(google-explicit-constructor) - Implicit conversion is intentional
       operator T const&() const noexcept { return content_; }
+      explicit operator std::string_view() const noexcept { return std::string_view(content_); }
       bool operator==(required_layer_name const&) const noexcept = default;
 
     private:

test/provider_test.cpp

@@ -170,9 +170,9 @@ TEST_CASE("Throw when two implicit providers are found for the same product")
 
   CHECK_THROWS_WITH(
     g.execute(),
-    ContainsSubstring(
-      "Multiple implicit providers found for product 'vertices_maker/happy_vertices") &&
-      ContainsSubstring("spill") && ContainsSubstring("passer"));
+    ContainsSubstring("Multiple implicit providers found for product '<suffix happy_vertices") &&
+      ContainsSubstring("by creator vertices_maker") && ContainsSubstring("in layer spill") &&
+      ContainsSubstring("node 'passer'"));
 }
 
 TEST_CASE("Throw when implicit provider insertion fails")
@@ -194,8 +194,9 @@ TEST_CASE("Throw when implicit provider insertion fails")
 
   CHECK_THROWS_WITH(
     g.execute(),
-    ContainsSubstring("Failed to create implicit provider for product selector 'vertices_maker/") &&
-      ContainsSubstring("happy_vertices") &&
+    ContainsSubstring(
+      "Failed to create implicit provider for product selector '<suffix happy_vertices") &&
+      ContainsSubstring("by creator vertices_maker") &&
       ContainsSubstring(
         "Implicit providers not yet supported for creators that created multiple data products"));
 }