:py:mod:`raesl.compile.typechecking.expr_checker`
=================================================

.. py:module:: raesl.compile.typechecking.expr_checker

.. autoapi-nested-parse::

   Check that expressions comply with the language requirements.



Module Contents
---------------

Classes
~~~~~~~

.. autoapisummary::

   raesl.compile.typechecking.expr_checker.ExprChecker




.. py:class:: ExprChecker(vps: Dict[str, Union[raesl.compile.ast.components.VarParam]], diag_store: raesl.compile.diagnostics.DiagnosticStore)


   Class for checking expressions.

   :param vps: Variables and parameters defined in the expression context.
   :param diag_store: Storage for found diagnostics.

   .. attribute:: reported_names

      Names of variables and variable parts that have been reported
      as error, to avoid duplicate error messages.

   .. py:method:: check_expr(expr: raesl.compile.ast.exprs.Expression) -> bool

      Check whether the expression follows all rules of the ESL language.

      :param expr: Expression to check.

      :returns:

                Whether the expression is considered to be sufficiently correct to continue
                    checking other parts of the construct around the expression.


   .. py:method:: check_relation_comparison(expr: raesl.compile.ast.exprs.RelationComparison) -> bool

      Check the provided relation comparison.

      :param expr: Relation comparison to check.

      :returns: Whether the expression is considered to be sufficiently correct.


   .. py:method:: _check_relation_side(side: raesl.compile.ast.exprs.DataValue) -> Optional[Tuple[raesl.compile.scanner.Token, Optional[raesl.compile.ast.types.BaseType], Optional[Set[str]]]]

      Check one side in a relation comparison.

      :param side: Side to check.

      :returns:

                Information about the checked side. None means an error has been reported,
                    otherwise a triplet of token, type, and supported units is returned
                    for as far as the side supports each notion.


   .. py:method:: _check_variable(var: raesl.compile.ast.exprs.VariableValue) -> bool

      Check that the variable exists in the context.

      :param var: Variable to check.

      :returns: Whether the variable was found.