The expression.py module

Summary

Classes

ExpressionTree

Provides the top-level abstract class for expression trees.

Exceptions

EmptyTreeError	Provides the exception for empty expression trees.
ExprSyntaxError	Provides the generic exception for syntax errors in expression trees.
TypeIdentifierError	Provides the exception for incorrect identifiers.

Functions

create_activate	Return the expression tree for the higher-order construct for activating with initial values.
create_activate_no_init	Return the expression tree for the higher-order construct for activating with default values.
create_binary	Return the expression tree for a binary operator.
create_call	Return the expression tree for a call to an operator.
create_case	Return the expression tree for the case operator.
create_change_ith	Return the expression tree for the with operator.
create_concat	Return the expression tree for the concat operator.
create_data_array	Return the expression tree for the data array operator.
create_data_struct	Return the expression tree for the data strictire operator.
create_fby	Return the expression tree for the init operator.
create_flatten	Return the expression tree for flattening a structured value.
create_fold	Return the expression tree for the higher-order construct for fold creation.
create_foldi	Return the expression tree for the higher-order construct for foldi creation.
create_foldw	Return the expression tree for the higher-order construct for foldw creation.
create_foldwi	Return the expression tree for the higher-order construct for foldwi creation.
create_higher_order_call	Return the expression tree for a call to an operator.
create_if	Return the expression tree for the if-then-else operator.
create_init	Return the expression tree for the init operator.
create_make	Return the expression tree for making a structured value.
create_map	Return the expression tree for the higher-order construct for map creation.
create_mapfold	Return the expression tree for the higher-order construct for mapfold creation.
create_mapfoldi	Return the expression tree for the higher-order construct for mapfoldi creation.
create_mapfoldw	Return the expression tree for the higher-order construct for mapfoldw creation.
create_mapfoldwi	Return the expression tree for the higher-order construct for mapfoldwi creation.
create_mapi	Return the expression tree for the higher-order construct for mapi creation.
create_mapw	Return the expression tree for the higher-order construct for mapw creation.
create_mapwi	Return the expression tree for the higher-order construct for mapdwi creation.
create_nary	Return the expression tree for a nary operator.
create_pre	Return the expression tree for the pre operator.
create_prj	Return the expression tree for the projection operator.
create_prj_dyn	Return the expression tree for the dynamic projection operator.
create_restart	Return the expression tree for the higher-order construct for restarting.
create_reverse	Return the expression tree for the reverse operator.
create_scalar_to_vector	Return the expression tree for the scalar-to-vector operator.
create_slice	Return the expression tree for the slice operator.
create_times	Return the expression tree for the times operator.
create_transpose	Return the expression tree for the transpose operator.
create_unary	Return the expression tree for a unary operator.

Constants

ET	Short name for an ExpressionTree instance to simplify the declarations.
EX	Extended expression tree to simplify use of the create functions.
LX	Extended lists of expression trees to simply the use of create functions.

Description

Provides helpers for creating expression trees.

Expression trees are intermediate structures to declare any arbitrary complex expressions. They create the corresponding SCADE Suite expressions in the context of a model element, such as the right part of an equation or the default value of an output.

This module provides functions to create an expression tree for any expression of the Scade language, including higher-order constructs. Thus, the intermediate structures or classes defining the expression trees can be opaque.

Notes: The typing is relaxed in this module to ease the constructs.

• ET is an alias for ExpressionTree to shorten the declarations.

• EX, which stands for extended expression tree, is defined as follows:

  Union[bool, int, float, str, suite.ConstVar, suite.NamedType, ET]
  

  This enhances the usability of these functions by accepting some values, such as Python literals, string values, or SCADE Python objects, as valid expression trees.

• LX, which stands for extended lists of expression trees, is defined as follows:

  Union[EX, List[EX]]
  

  When the expressions accept an arbitrary number of input flows, such as if-then-else or fby, you can provide either one expression tree or a list of expression trees.

Module detail

ET

Short name for an ExpressionTree instance to simplify the declarations.

EX

Extended expression tree to simplify use of the create functions.

LX

Extended lists of expression trees to simply the use of create functions.