Calculators
===========

Calculators compute values of expressions, residuals of equations and truth-values of logical expressions.

.. cpp:namespace:: hysj

.. cpp:namespace-push:: calculators

   
Basic
-----

:cpp:include:`#include<hysj/calculators/basic.hpp>`

In namespace :cpp:any:`calculators`:

A basic calculator implementation. Does a recursive post-order traversal from each operation to be evaluated. Uses cached results if they exists, else evaluates the operation.

.. cpp:struct:: basic

   .. cpp:type:: cache_type
   .. cpp:member:: mathematics::program program
   .. cpp:member:: cache_type cache

   .. cpp:function:: basic(const mathematics::program &p)

      | Create a calculator for :cpp:expr:`p`.
      |		   

   .. cpp:function:: void operator()(const mathematics::equation_ids &equations,    \
                                     const mathematics::expression_ids &parameters, \ 
                                     std::span<real> valuation,                     \
                                     std::span<real> result);

      | Stores :cpp:expr:`valuation` for :cpp:expr:`parameters` in cache, compute the residuals of the :cpp:expr:`equations` and store them in :cpp:expr:`result`.
      |
      
.. cpp:namespace-pop::