# Package weka.core.expressionlanguage.common

- Interface Summary
  Interface | Description
  --- | ---
  Primitives.BooleanExpression | An AST node for an expression of boolean type
  Primitives.DoubleExpression | An AST node for an expression of double type
  Primitives.StringExpression | An AST node for an expression of String type

- Class Summary
  Class | Description
  --- | ---
  IfElseMacro | A macro declaration exposing the `ifelse` function.
  JavaMacro | A macro declarations that exposes the java macro to a program.
  MacroDeclarationsCompositor | A helper class that allows to combine several macro declarations together.
  MathFunctions | Macro declarations for common mathematical functions.
  NoMacros | A macro declarations that contains no macros at all
  NoVariables | A variable declarations that contains no variables
  Operators | A class to specify the semantics of operators in the expressionlanguage
  Primitives | A class providing AST (abstract syntax tree) nodes to support primitive types.
  Primitives.BooleanConstant | An AST node representing a boolean constant
  Primitives.BooleanVariable | An AST node representing a boolean variable
  Primitives.DoubleConstant | An AST node representing a double constant
  Primitives.DoubleVariable | An AST node representing a double variable
  Primitives.StringConstant | An AST node representing a string constant
  Primitives.StringVariable | An AST node representing a string variable
  SimpleVariableDeclarations | A set of customizable variable declarations for primitive types.
  SimpleVariableDeclarations.VariableInitializer | A class to initialize variables that have been declared by a `SimpleVariableDeclarations` class and used inside a program
  VariableDeclarationsCompositor | A helper class that allows to combine several variable declarations together.