ICallable
=========

.. cpp:class:: pandas::ICallable

   pandas C++ class.

Example
-------

.. code-block:: cpp

   #include <pandas/pandas.h>
   using namespace pandas;

   // Use ICallable
   ICallable obj;
   // ... operations ...

Other Methods
-------------

.. list-table::
   :widths: 40 20 15 25
   :header-rows: 1

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``virtual ApplyCellResult invoke_cell(const MapCellInput&) const = 0``
     - virtual ApplyCellResult
     - pd_callable_handle.h:62
     - :ref:`View <example-icallable-invoke_cell-0>`
   * - ``virtual ApplyCellResult invoke_col(const ApplyColInput&) const``
     - virtual ApplyCellResult
     - pd_callable_handle.h:73
     - 
   * - ``virtual ApplyCellResult invoke_row(const ApplyRowInput&) const``
     - virtual ApplyCellResult
     - pd_callable_handle.h:68
     - 
   * - ``virtual DataFrame invoke_with_dataframe(const DataFrame&) const``
     - virtual DataFrame
     - pd_callable_handle.h:84
     - :ref:`View <example-icallable-invoke_with_dataframe-1>`
   * - ``virtual std::string repr() const = 0``
     - virtual std::string
     - pd_callable_handle.h:57
     - :ref:`View <example-icallable-repr-2>`
   * - ``throw_invoke_unsupported("invoke_row")``
     - 
     - pd_callable_handle.h:69
     - 
   * - ``throw_invoke_unsupported("invoke_col")``
     - 
     - pd_callable_handle.h:74
     - 


Code Examples
-------------

The following examples are extracted from the test suite.

.. _example-icallable-invoke_cell-0:

.. dropdown:: invoke_cell (pd_test_5_all.cpp:91860)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 91850
      :emphasize-lines: 11

      }
      
      // --- f_test_24_dataframe_where_core_9.cpp ---
      
      namespace f_test_24_dataframe_where_core_9_ns {
      
      class IdentityCallable : public pandas::ICallable {
      public:
          std::string repr() const override { return "IdentityCallable"; }
      
          pandas::ApplyCellResult invoke_cell(const pandas::MapCellInput&) const override {
              // Not used in where_resolved path; throw to make accidental use loud.
              throw pandas::ValueError("IdentityCallable: invoke_cell unsupported");
          }
      
          // The where dispatcher calls this entry — proof-test signature mirrors
          // plan C-24.2 Change C-24.2 ("cond.callable_ptr->invoke_with_dataframe(*this)").
          pandas::DataFrame invoke_with_dataframe(const pandas::DataFrame& df) const override {
              return df;
          }
      };

.. _example-icallable-invoke_with_dataframe-1:

.. dropdown:: invoke_with_dataframe (pd_test_5_all.cpp:91866)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 91856
      :emphasize-lines: 11

      class IdentityCallable : public pandas::ICallable {
      public:
          std::string repr() const override { return "IdentityCallable"; }
      
          pandas::ApplyCellResult invoke_cell(const pandas::MapCellInput&) const override {
              // Not used in where_resolved path; throw to make accidental use loud.
              throw pandas::ValueError("IdentityCallable: invoke_cell unsupported");
          }
      
          // The where dispatcher calls this entry — proof-test signature mirrors
          // plan C-24.2 Change C-24.2 ("cond.callable_ptr->invoke_with_dataframe(*this)").
          pandas::DataFrame invoke_with_dataframe(const pandas::DataFrame& df) const override {
              return df;
          }
      };
      
      class AllTrueCallable : public pandas::ICallable {
      public:
          std::string repr() const override { return "AllTrueCallable"; }
      
          pandas::ApplyCellResult invoke_cell(const pandas::MapCellInput&) const override {

.. _example-icallable-repr-2:

.. dropdown:: repr (pd_test_1_all.cpp:10906)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 10896
      :emphasize-lines: 11

          std::cout << " -> tests passed" << std::endl;
      }
      
      void pd_test_extension_index_repr() {
          std::cout << "========= repr =========================";
      
          pandas::CategoricalArray arr({"a", "b", "c"});
          // Use ExtensionIndex<CategoricalArray> directly to test base class repr
          pandas::ExtensionIndex<pandas::CategoricalArray> idx(arr, "test");
      
          std::string repr_str = idx.repr();
      
          bool passed = (!repr_str.empty() && repr_str.find("ExtensionIndex") != std::string::npos);
          if (!passed) {
              std::cout << "  [FAIL] : in pd_test_extension_index_repr() : repr check failed" << std::endl;
              throw std::runtime_error("pd_test_extension_index_repr failed");
          }
      
          std::cout << " -> tests passed" << std::endl;
      }