# Package weka.core.expressionlanguage.core

- Interface Summary
  Interface | Description
  --- | ---
  Macro | Interface for compile time macros to enable meta programming
  MacroDeclarations | Interface to expose macros to a program.
  Node | A node of the AST (abstract syntax tree) for a program
  VariableDeclarations | Interface to expose variables to a program.

- Exception Summary
  Exception | Description
  --- | ---
  SemanticException | An exception that should be used if a program doesn't have valid semantics
  SyntaxException | An exception to represent an invalid syntax of a program