Package com.singularsys.jep.misc

# Class NullParser

java.lang.Object
com.singularsys.jep.misc.NullParser

All Implemented Interfaces:
  `JepComponent`, `Parser`, `Serializable`

public class NullParser extends Object implements Parser
A Parser which cannot actually parse expressions. Used in situations where a small footprint Jep instance is needed which does not require parsing facilities.

See Also:
  - Serialized Form

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final NullParser`
  `NULL_PARSER`
  Singleton instance.

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `NullParser()`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `Node`
  `continueParse()`
  Read the next equation from the stream.
  `JepComponent`
  `getLightWeightInstance()`
  Gets a light-weight instance suitable for using in multiple threads.
  `void`
  `init(Jep jep)`
  Initialize the component.
  `Node`
  `parse(Reader stream)`
  Parse a single equation from a stream
  `void`
  `restart(Reader stream)`
  Restart the parser for reentrant parsing of multiple equations.

  ### Methods inherited from class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Field Details

  - ### NULL_PARSER

    public static final NullParser NULL_PARSER
    Singleton instance.

- ## Constructor Details

  - ### NullParser

    public NullParser()

- ## Method Details

  - ### init

    public void init(Jep jep)
    Description copied from interface: `JepComponent`
    Initialize the component. This method is called whenever a component is added to Jep. Hence, it allows components to keep track of the other components they may rely on.
    Specified by:
      `init` in interface `JepComponent`
    Parameters:
      `jep` - the current Jep instance

  - ### continueParse

    public Node continueParse() throws ParseException
    Description copied from interface: `Parser`
    Read the next equation from the stream. By default, empty expressions should be silently ignored.
    Specified by:
      `continueParse` in interface `Parser`
    Returns:
      the root node of the expression tree
    Throws:
      `ParseException` - always

  - ### parse

    public Node parse(Reader stream) throws ParseException
    Description copied from interface: `Parser`
    Parse a single equation from a stream
    Specified by:
      `parse` in interface `Parser`
    Parameters:
      `stream` - input reader
    Returns:
      the root node of the expression tree
    Throws:
      `ParseException` - always

  - ### restart

    public void restart(Reader stream)
    Description copied from interface: `Parser`
    Restart the parser for reentrant parsing of multiple equations.
    Specified by:
      `restart` in interface `Parser`
    Parameters:
      `stream` - input stream

  - ### getLightWeightInstance

    public JepComponent getLightWeightInstance()
    Description copied from interface: `JepComponent`
    Gets a light-weight instance suitable for using in multiple threads.
    Specified by:
      `getLightWeightInstance` in interface `JepComponent`
    Returns:
      either a new instance, null or 'this'.