Initial lambda extraction (#566)

* initial lambda extraction

* older model migration and unify with new helper

* improved config checks and parameter reader

* reduce scope

* Update GridKit/Testing/Testing.hpp

Co-authored-by: superwhiskers <whiskerdev@protonmail.com>

* empty overrides

---------

Co-authored-by: lukelowry <lukelowry@users.noreply.github.com>
Co-authored-by: superwhiskers <whiskerdev@protonmail.com>

Author: lukelowry

CHANGELOG.md

@@ -8,6 +8,8 @@
 - Added `Bus::setFault` to apply or clear a fault to ground directly at a bus.
 - Removed the `BusFault` class in favor of `Bus::setFault`.
 - Added `enable` and `disable` solver events that put a branch in or out of service.
+- `verify()` returns `Model::ConfigurationChecks` listing every configuration problem instead of an error count.
+- Added `Model::ParameterReader`
 
 ## v0.2
 

GridKit/Model/CMakeLists.txt

@@ -9,5 +9,10 @@ add_subdirectory(PhasorDynamics)
 add_subdirectory(PowerFlow)
 add_subdirectory(PowerElectronics)
 
-install(FILES Evaluator.hpp VariableMonitor.hpp VariableMonitorController.hpp
-        DESTINATION include/GridKit/Model)
+install(
+  FILES ConfigurationChecks.hpp
+        Evaluator.hpp
+        ParameterReader.hpp
+        VariableMonitor.hpp
+        VariableMonitorController.hpp
+  DESTINATION include/GridKit/Model)

GridKit/Model/ConfigurationChecks.hpp

@@ -0,0 +1,68 @@
+/**
+ * @file ConfigurationChecks.hpp
+ * @author Luke Lowery (lukel@tamu.edu)
+ * @brief Collects the configuration problems found by a model.
+ */
+
+#pragma once
+
+#include <format>
+#include <string>
+#include <string_view>
+#include <vector>
+
+namespace GridKit
+{
+  namespace Model
+  {
+    /**
+     * @brief Collects the configuration problems found by a model.
+     *
+     * A model's verify() fills one instance with a message for every
+     * condition that does not hold and returns it. The caller decides how
+     * the messages are reported; passed() is true when there are none.
+     */
+    class [[nodiscard]] ConfigurationChecks
+    {
+    public:
+      ConfigurationChecks() = default;
+
+      /// @param[in] model Model name that prefixes every recorded message.
+      explicit ConfigurationChecks(std::string_view model)
+        : prefix_(std::format("{}: ", model))
+      {
+      }
+
+      /// Record a problem.
+      void fail(std::string_view message)
+      {
+        errors_.push_back(prefix_ + std::string(message));
+      }
+
+      /// Record the message when the condition does not hold.
+      void check(bool condition, std::string_view message)
+      {
+        if (!condition)
+        {
+          fail(message);
+        }
+      }
+
+      /// True when no check has failed.
+      bool passed() const
+      {
+        return errors_.empty();
+      }
+
+      /// Every recorded message, in the order the checks ran.
+      const std::vector<std::string>& errors() const
+      {
+        return errors_;
+      }
+
+    private:
+      std::string              prefix_;
+      std::vector<std::string> errors_;
+    };
+  } // namespace Model
+} // namespace GridKit

GridKit/Model/ParameterReader.hpp

@@ -0,0 +1,154 @@
+/**
+ * @file ParameterReader.hpp
+ * @author Luke Lowery (lukel@tamu.edu)
+ * @brief Typed parameter loading from model data containers.
+ */
+
+#pragma once
+
+#include <cmath>
+#include <format>
+#include <optional>
+#include <stdexcept>
+#include <string_view>
+#include <variant>
+
+#include <magic_enum/magic_enum.hpp>
+
+#include <GridKit/Constants.hpp>
+#include <GridKit/Model/PhasorDynamics/ModelData.hpp>
+
+namespace GridKit
+{
+  namespace Model
+  {
+    /**
+     * @brief Reads typed parameters out of a model data container.
+     *
+     * A read method returns the provided value or std::nullopt when the
+     * parameter is omitted. The model chooses a default or requires a value.
+     * Invalid values are rejected with std::invalid_argument naming the
+     * model and parameter. Real parameters accept integer values and must
+     * be finite.
+     *
+     * @tparam ModelDataT A model data container satisfying
+     *         PhasorDynamics::ModelData.
+     */
+    template <PhasorDynamics::ModelData ModelDataT>
+    class ParameterReader
+    {
+    public:
+      using RealT       = typename ModelDataT::RealT;
+      using IdxT        = typename ModelDataT::IdxT;
+      using ParametersT = typename ModelDataT::Parameters;
+
+      /**
+       * @param[in] data Model data container to read from.
+       * @param[in] model Model name used in rejection messages.
+       */
+      ParameterReader(const ModelDataT& data, const char* model)
+        : parameters_(data.parameters),
+          model_(model)
+      {
+      }
+
+      /// Read an optional real parameter.
+      [[nodiscard]] std::optional<RealT> readReal(ParametersT key) const
+      {
+        const auto* value = find(key);
+        if (value == nullptr)
+        {
+          return std::nullopt;
+        }
+
+        RealT real{};
+        if (const auto* real_value = std::get_if<RealT>(value))
+        {
+          real = *real_value;
+        }
+        else if (const auto* integer_value = std::get_if<IdxT>(value))
+        {
+          real = static_cast<RealT>(*integer_value);
+        }
+        else
+        {
+          reject(key, "must be numeric");
+        }
+
+        if (!std::isfinite(real))
+        {
+          reject(key, "must be finite");
+        }
+
+        return real;
+      }
+
+      /// Read an optional non-negative real parameter.
+      [[nodiscard]] std::optional<RealT> readNonNegative(ParametersT key) const
+      {
+        auto value = readReal(key);
+        if (value && *value < ZERO<RealT>)
+        {
+          reject(key, "must be non-negative");
+        }
+        return value;
+      }
+
+      /// Read an optional boolean parameter.
+      [[nodiscard]] std::optional<bool> readBool(ParametersT key) const
+      {
+        return readExact<bool>(key, "must be boolean");
+      }
+
+      /// Read an optional integer parameter.
+      [[nodiscard]] std::optional<IdxT> readInteger(ParametersT key) const
+      {
+        return readExact<IdxT>(key, "must be an integer");
+      }
+
+    private:
+      using ParameterMapT = decltype(ModelDataT::parameters);
+      using ValueT        = typename ParameterMapT::mapped_type;
+
+      /// The provided value, or nullptr when the parameter is omitted.
+      const ValueT* find(ParametersT key) const
+      {
+        const auto entry = parameters_.find(key);
+        if (entry == parameters_.end())
+        {
+          return nullptr;
+        }
+        return &entry->second;
+      }
+
+      /// Read an optional parameter that must hold exactly a T.
+      template <typename T>
+      [[nodiscard]] std::optional<T> readExact(ParametersT key, std::string_view reason) const
+      {
+        const auto* value = find(key);
+        if (value == nullptr)
+        {
+          return std::nullopt;
+        }
+
+        const auto* exact_value = std::get_if<T>(value);
+        if (exact_value == nullptr)
+        {
+          reject(key, reason);
+        }
+
+        return *exact_value;
+      }
+
+      /// Reject the model data with a message naming the model and parameter.
+      [[noreturn]] void reject(ParametersT key, std::string_view reason) const
+      {
+        throw std::invalid_argument(
+            std::format("{}: parameter '{}' {}", model_, magic_enum::enum_name(key), reason));
+      }
+
+      const ParameterMapT& parameters_;
+      const char*          model_;
+    };
+  } // namespace Model
+} // namespace GridKit

GridKit/Model/PhasorDynamics/Branch/Branch.hpp

@@ -72,7 +72,8 @@ namespace GridKit
       virtual int setAbsoluteTolerance(RealT rel_tol) override final;
       virtual int evaluateResidual() override final;
       virtual int evaluateJacobian() override final;
-      virtual int verify() const override final;
+
+      virtual Model::ConfigurationChecks verify() const override final;
 
       int setInService(bool in_service);
 

GridKit/Model/PhasorDynamics/Branch/BranchImpl.hpp

@@ -154,34 +154,27 @@ namespace GridKit
     }
 
     template <typename scalar_type, typename index_type>
-    int Branch<scalar_type, index_type>::verify() const
+    Model::ConfigurationChecks Branch<scalar_type, index_type>::verify() const
     {
-      int ret = parameter_error_count_;
+      Model::ConfigurationChecks checks("Branch");
 
-      auto check = [&](bool condition, const char* message)
-      {
-        if (!condition)
-        {
-          Log::error() << "Branch: " << message << '\n';
-          ret += 1;
-        }
-      };
-
-      check(bus1_ != nullptr, "bus1 pointer is null");
-      check(bus2_ != nullptr, "bus2 pointer is null");
-
-      check(std::isfinite(R_), "R must be finite");
-      check(std::isfinite(X_), "X must be finite");
-      check(std::isfinite(G_), "G must be finite");
-      check(std::isfinite(B_), "B must be finite");
-      check(std::isfinite(Gmag_), "Gmag must be finite");
-      check(std::isfinite(Bmag_), "Bmag must be finite");
-      check(std::isfinite(tap_), "tap must be finite");
-      check(std::isfinite(phase_), "phase must be finite");
-      check(R_ * R_ + X_ * X_ > RealT{0.0}, "R and X cannot both be zero");
-      check(tap_ > RealT{0.0}, "tap must be positive");
-
-      return ret;
+      checks.check(parameter_error_count_ == 0, "model data has invalid parameters");
+
+      checks.check(bus1_ != nullptr, "bus1 pointer is null");
+      checks.check(bus2_ != nullptr, "bus2 pointer is null");
+
+      checks.check(std::isfinite(R_), "R must be finite");
+      checks.check(std::isfinite(X_), "X must be finite");
+      checks.check(std::isfinite(G_), "G must be finite");
+      checks.check(std::isfinite(B_), "B must be finite");
+      checks.check(std::isfinite(Gmag_), "Gmag must be finite");
+      checks.check(std::isfinite(Bmag_), "Bmag must be finite");
+      checks.check(std::isfinite(tap_), "tap must be finite");
+      checks.check(std::isfinite(phase_), "phase must be finite");
+      checks.check(R_ * R_ + X_ * X_ > RealT{0.0}, "R and X cannot both be zero");
+      checks.check(tap_ > RealT{0.0}, "tap must be positive");
+
+      return checks;
     }
 
     /// Put the branch in or out of service; out of service, it injects no current.

GridKit/Model/PhasorDynamics/Bus/BusSignalVoltageIn/BusSignalVoltageIn.hpp

@@ -24,7 +24,7 @@ namespace GridKit
      * components _Vr_ and _Vi_ are read directly from signal inlets
      * `vr` and `vi` whenever Vr() or Vi() is called; the bus stores no
      * voltage of its own and never modifies it. Both voltage inlets are
-     * mandatory: verify() logs an error and throws for an inlet that is not
+     * mandatory: verify() reports an error for an inlet that is not
      * connected to a linked signal, and reading the voltage through an
      * unlinked inlet throws. No default voltage is ever used. The bus has
      * no unknowns and no equations (size() == 0, like @ref BusInfinite).
@@ -70,13 +70,14 @@ namespace GridKit
 
       virtual int setBusID(IdxT) override final;
       virtual int allocate() override final;
-      virtual int verify() const override final;
       virtual int tagDifferentiable() override final;
       virtual int setAbsoluteTolerance(RealT rel_tol) override final;
       virtual int initialize() override final;
       virtual int evaluateResidual() override final;
       virtual int evaluateJacobian() override final;
 
+      virtual Model::ConfigurationChecks verify() const override final;
+
       virtual BusTypeT BusType() const override final
       {
         return BusTypeT::SIGNAL_VOLTAGE_IN;