Swan constructs

This section describes the ansys.scadeone.core.swan module which contains all classes available to represent a Swan model.

Some class descriptions use the Extended Backus-Naur form to represent Swan constructs.

Each class defined in this module corresponds to a Swan construct. For instance the ModuleBody class represents a Swan module body, the ConstDeclarations class represents constant declarations, and the Diagram class represents a diagram. This pattern continues for all Swan constructs.

The class hierarchy closely mirrors the Swan language and its grammar. Refer to the Help menu in the Swan IDE for a complete description of the Swan language.

Swan objects can be created from a Swan model read from a project or built from scratch using the classes described in the following sections.

Swan objects as strings

Swan objects can be complex, and pretty-printing them is often desirable. The default __str__() method is not always sufficient to represent a Swan object as a string. To obtain a string representation of a Swan construct, use the ansys.scadeone.core.swan.swan_to_str() method. Example:

from ansys.scadeone.core.swan import swan_to_str
print(swan_to_str(my_construct))

The default __str__() method is implemented for the following classes: Luid, Lunum, Literal, Identifier, PathIdentifier, Pattern derived classes, Pragma, and pragma related classes (see: Diagram Pragmas), and ProtectedItem.

Protected object concept

The Swan editor allows the user to enter syntactically invalid Swan code. Such code is protected to become acceptable tokens for the Swan parser. See Protected items for more details.

• Basic classes
  • SwanItem class
  • HasPragma class
  • Identifier classes
  • Miscellaneous
• Module and global declarations
  • Modules and Interfaces
  • Type and global flow declarations
  • Operators
• Operator body
  • Operator sections
  • Variable declarations
  • Equations
  • Activations
  • State machines
  • Formal properties
  • Emissions
  • Diagrams
• Expressions
  • Identifiers and atoms
  • Bitwise, boolean, arithmetic, relational, sequential
  • Array, structure and variant
  • Selection
  • Sequential
  • Operator instance
  • Forward expression
• Groups
  • Group construction
  • Group projection and renaming
• Memory annotations
• Pragmas
  • Pragma
  • Diagram Pragmas
  • Code generation pragmas
  • Documentation pragmas
  • Traceability pragmas
  • Test pragmas
• Protected items
  • Protection class
  • List of protected items
  • Markup helper