Consolidate implementations of find_property

Summary: Remove duplicate implementation in `mstch_compat`, to prevent divergence in upcoming changes.

Reviewed By: praihan

Differential Revision: D79453615

fbshipit-source-id: c29f5665577e04d9c7608a93bed79be7ed079f86

Author: hchokshi

third-party/thrift/src/thrift/compiler/whisker/eval_context.cc

@@ -27,6 +27,42 @@ namespace whisker {
 
 namespace {
 
+/**
+ * A class representing the bag of properties at the global scope (even before
+ * the root scope).
+ *
+ * This is a bespoke implementation primarily for debugging purposes.
+ */
+class global_scope_object : public map {
+ public:
+  explicit global_scope_object(map::raw properties)
+      : properties_(std::move(properties)) {}
+
+  std::optional<object> lookup_property(
+      std::string_view identifier) const override {
+    if (auto property = properties_.find(identifier);
+        property != properties_.end()) {
+      return property->second;
+    }
+    return std::nullopt;
+  }
+
+  void print_to(tree_printer::scope& scope, const object_print_options& options)
+      const override {
+    scope.print("<global scope> (size={})", properties_.size());
+    for (const auto& [key, value] : properties_) {
+      whisker::print_to(value, scope.make_child("'{}' → ", key), options);
+    }
+  }
+
+ private:
+  map::raw properties_;
+};
+
+} // namespace
+
+namespace detail {
+
 std::optional<object> find_property(
     diagnostics_engine& diags,
     const object& self,
@@ -65,46 +101,14 @@ std::optional<object> find_property(
       });
 }
 
-/**
- * A class representing the bag of properties at the global scope (even before
- * the root scope).
- *
- * This is a bespoke implementation primarily for debugging purposes.
- */
-class global_scope_object : public map {
- public:
-  explicit global_scope_object(map::raw properties)
-      : properties_(std::move(properties)) {}
-
-  std::optional<object> lookup_property(
-      std::string_view identifier) const override {
-    if (auto property = properties_.find(identifier);
-        property != properties_.end()) {
-      return property->second;
-    }
-    return std::nullopt;
-  }
-
-  void print_to(tree_printer::scope& scope, const object_print_options& options)
-      const override {
-    scope.print("<global scope> (size={})", properties_.size());
-    for (const auto& [key, value] : properties_) {
-      whisker::print_to(value, scope.make_child("'{}' → ", key), options);
-    }
-  }
-
- private:
-  map::raw properties_;
-};
-
-} // namespace
+} // namespace detail
 
 std::optional<object> eval_context::lexical_scope::lookup_property(
     diagnostics_engine& diags, const ast::identifier& identifier) {
   if (auto local = locals_.find(identifier.name); local != locals_.end()) {
     return local->second;
   }
-  return find_property(diags, this_ref_, identifier);
+  return detail::find_property(diags, this_ref_, identifier);
 }
 
 eval_context::eval_context(diagnostics_engine& diags, object globals)
@@ -221,7 +225,7 @@ eval_context::look_up_object(const ast::variable_lookup& lookup) {
              ++component) {
           try {
             std::optional<object> next =
-                find_property(diags_, *current, component->property);
+                detail::find_property(diags_, *current, component->property);
             if (!next.has_value()) {
               return unexpected(eval_property_lookup_error(
                   *current, /* missing_from */

third-party/thrift/src/thrift/compiler/whisker/eval_context.h

@@ -140,6 +140,19 @@ class eval_name_already_bound_error {
   std::string name_;
 };
 
+namespace detail {
+
+/**
+ * Try resolve a property on a Whisker object.
+ * Returns std::nullopt if the property is not found.
+ */
+std::optional<object> find_property(
+    diagnostics_engine& diags,
+    const object& self,
+    const ast::identifier& identifier);
+
+} // namespace detail
+
 /**
  * An eval_context is responsible for name resolution within Whisker templates
  * and maintains necessary state to achieve when a template is rendered (aka

third-party/thrift/src/thrift/compiler/whisker/mstch_compat.cc

@@ -16,6 +16,7 @@
 
 #include <boost/algorithm/string/predicate.hpp>
 #include <thrift/compiler/whisker/detail/overload.h>
+#include <thrift/compiler/whisker/eval_context.h>
 #include <thrift/compiler/whisker/mstch_compat.h>
 
 #include <cassert>
@@ -202,37 +203,14 @@ class mstch_object_proxy
 
     const mstch_object::lookup_result self_value =
         proxied_->at(self_property->first);
-    const object* self_whisker_obj = std::get_if<object>(&self_value);
-    if (self_whisker_obj == nullptr) {
-      return std::nullopt;
+    if (const object* self_whisker_obj = std::get_if<object>(&self_value)) {
+      return detail::find_property(
+          diags_,
+          *self_whisker_obj,
+          ast::identifier{source_range{}, std::string(self_property->second)});
     }
 
-    return self_whisker_obj->visit(
-        [&](const map::ptr& m) -> std::optional<object> {
-          return m->lookup_property(self_property->second);
-        },
-        [&](const native_handle<>& h) -> std::optional<object> {
-          if (const whisker::prototype<>::descriptor* descriptor =
-                  h.proto()->find_descriptor(self_property->second)) {
-            return detail::variant_match(
-                *descriptor,
-                [&](const prototype<>::property& prop)
-                    -> std::optional<object> {
-                  return prop.function->invoke(native_function::context{
-                      {} /* identifier location */,
-                      diags_,
-                      *self_whisker_obj,
-                      {} /* positional arguments */,
-                      {} /* named arguments */,
-                  });
-                },
-                [&](const prototype<>::fixed_object& fixed)
-                    -> std::optional<object> { return fixed.value; });
-          }
-          return std::nullopt;
-        },
-        // Default - no property found
-        [](auto const&) -> std::optional<object> { return std::nullopt; });
+    return std::nullopt;
   }
 };