Package jflex

Class Action

  • public final class Action
extends java.lang.Object
    Encapsulates an action in the specification.

    It stores the Java code as String together with a priority (line number in the specification).

    Version:
    JFlex 1.7.0

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static int BACKWARD_ACTION
      Action of the backward pass for lookahead
      (package private) java.lang.String content
      The Java code this Action represents
      private int entryState
      The entry state of the corresponding forward DFA (if general lookahead)
      static int FINITE_CHOICE
      Action of a lookahead expression r1/r2 with a finite choice of fixed lengths in r2
      static int FIXED_BASE
      Action of a lookahead expression r1/r2 with fixed length r1
      static int FIXED_LOOK
      Action of a lookahead expression r1/r2 with fixed length r2
      static int FORWARD_ACTION
      Action of the 2nd forward pass for lookahead
      static int GENERAL_LOOK
      Action of a general lookahead expression
      private int kind
      Which kind of action this is.
      private int len
      The length of the lookahead (if fixed)
      static int NORMAL
      A normal action
      (package private) int priority
      The priority (i.e.

    • Constructor Summary

      Constructors 
      Constructor Description
      Action​(int kind)
      Creates a new Action object of the specified kind.
      Action​(java.lang.String content, int priority)
      Creates a new Action object with specified content and line number.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      Action copyChoice​(int length)
      copyChoice.
      boolean equals​(java.lang.Object o)
      int getEntryState()
      Return the corresponding entry state for the forward DFA (if this is a general lookahead expression)
      Action getHigherPriority​(Action other)
      Compares the priority value of this Action with the specified action.
      int getLookLength()
      The length of the lookahead or base if this is a fixed length lookahead action.
      int hashCode()
      Calculate hash value.
      boolean isEmittable()
      Return true if code for this is action should be emitted, false if it is a BACK/FORWARD lookahead action.
      boolean isEquiv​(Action a)
      Returns true iff the parameter is an Action with the same content as this one.
      boolean isGenLookAction()
      Return true iff this is action belongs to a general lookahead rule.
      int lookAhead()
      Return kind of lookahead.
      java.lang.String lookString()
      String representation of the lookahead kind of this action.
      void setEntryState​(int entryState)
      Set the corresponding entry state for the forward DFA of this action (if this is a general lookahead expression)
      void setLookAction​(int kind, int data)
      Sets the lookahead kind and data for this action
      java.lang.String toString()
      Returns the String representation of this object.

      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait

    • Field Detail

      • FIXED_BASE

        public static final int FIXED_BASE
        Action of a lookahead expression r1/r2 with fixed length r1
        See Also:
        Constant Field Values

      • FIXED_LOOK

        public static final int FIXED_LOOK
        Action of a lookahead expression r1/r2 with fixed length r2
        See Also:
        Constant Field Values

      • FINITE_CHOICE

        public static final int FINITE_CHOICE
        Action of a lookahead expression r1/r2 with a finite choice of fixed lengths in r2
        See Also:
        Constant Field Values

      • GENERAL_LOOK

        public static final int GENERAL_LOOK
        Action of a general lookahead expression
        See Also:
        Constant Field Values

      • FORWARD_ACTION

        public static final int FORWARD_ACTION
        Action of the 2nd forward pass for lookahead
        See Also:
        Constant Field Values

      • BACKWARD_ACTION

        public static final int BACKWARD_ACTION
        Action of the backward pass for lookahead
        See Also:
        Constant Field Values

      • content

        java.lang.String content
        The Java code this Action represents

      • priority

        int priority
        The priority (i.e. line number in the specification) of this Action.

      • kind

        private int kind
        Which kind of action this is. (normal, a/b with fixed length a, fixed length b, etc)

      • len

        private int len
        The length of the lookahead (if fixed)

      • entryState

        private int entryState
        The entry state of the corresponding forward DFA (if general lookahead)

    • Constructor Detail

      • Action

        public Action​(java.lang.String content,
              int priority)
        Creates a new Action object with specified content and line number.
        Parameters:
        content - java code
        priority - line number

    • Method Detail

      • getHigherPriority

        public Action getHigherPriority​(Action other)
        Compares the priority value of this Action with the specified action.
        Parameters:
        other - the other Action to compare this Action with.
        Returns:
        this Action if it has higher priority - the specified one, if not.

      • toString

        public java.lang.String toString()
        Returns the String representation of this object.
        Overrides:
        toString in class java.lang.Object
        Returns:
        string representation of the action

      • isEquiv

        public boolean isEquiv​(Action a)
        Returns true iff the parameter is an Action with the same content as this one.
        Parameters:
        a - the object to compare this Action with
        Returns:
        true if the action strings are equal

      • hashCode

        public int hashCode()
        Calculate hash value.
        Overrides:
        hashCode in class java.lang.Object
        Returns:
        a hash value for this Action

      • equals

        public boolean equals​(java.lang.Object o)

        Test for equality to another object.

        This action equals another object if the other object is an equivalent action.

        Overrides:
        equals in class java.lang.Object
        See Also:
        isEquiv(Action)

      • isGenLookAction

        public boolean isGenLookAction()
        Return true iff this is action belongs to a general lookahead rule.
        Returns:
        true if this actions belongs to a general lookahead rule.

      • isEmittable

        public boolean isEmittable()
        Return true if code for this is action should be emitted, false if it is a BACK/FORWARD lookahead action.
        Returns:
        true if code should be emitted for this action.

      • lookAhead

        public int lookAhead()
        Return kind of lookahead.
        Returns:
        a int.

      • setLookAction

        public void setLookAction​(int kind,
                          int data)
        Sets the lookahead kind and data for this action
        Parameters:
        kind - which kind of lookahead it is
        data - the length for fixed length lookaheads.

      • getLookLength

        public int getLookLength()
        The length of the lookahead or base if this is a fixed length lookahead action.
        Returns:
        a int.

      • getEntryState

        public int getEntryState()
        Return the corresponding entry state for the forward DFA (if this is a general lookahead expression)
        Returns:
        the forward DFA entry state (+1 is the backward DFA)

      • setEntryState

        public void setEntryState​(int entryState)
        Set the corresponding entry state for the forward DFA of this action (if this is a general lookahead expression)
        Parameters:
        entryState - a int.

      • copyChoice

        public Action copyChoice​(int length)
        copyChoice.
        Parameters:
        length - a int.
        Returns:
        a Action object.

      • lookString

        public java.lang.String lookString()
        String representation of the lookahead kind of this action.
        Returns:
        the string representation