Package org.parboiled.support

Class DefaultValueStack<V>

java.lang.Object
org.parboiled.support.DefaultValueStack<V>
Type Parameters:
V - the type of the value objects
All Implemented Interfaces:
Iterable<V>, ValueStack<V>
Direct Known Subclasses:
DebuggingValueStack
public class DefaultValueStack<V> extends Object implements ValueStack<V>
An implementation of a stack of value objects providing an efficient snapshot capability and a number of convenience methods. The current state of the stack can be saved and restored in small constant time with the methods takeSnapshot() and restoreSnapshot(Object) ()}. The implementation also serves as an Iterable over the current stack values (the values are being provided with the last value (on top of the stack) first).

  • Constructor Summary

    Constructors
    Constructor
    Description
    DefaultValueStack()
    Initializes an empty value stack.
    DefaultValueStack(Iterable<V> values)
    Initializes a value stack containing the given values with the last value being at the top of the stack.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    clear()
    Clears all values.
    void
    dup()
    Duplicates the top value.
    boolean
    isEmpty()
    Determines whether the stack is empty.
    Iterator<V>
    iterator()
     
    V
    peek()
    Returns the value at the top of the stack without removing it.
    V
    peek(int down)
    Returns the value the given number of elements below the top of the stack without removing it.
    void
    poke(int down, V value)
    Replaces the element the given number of elements below the current top of the stack.
    void
    poke(V value)
    Replaces the current top value with the given value.
    V
    pop()
    Removes the value at the top of the stack and returns it.
    V
    pop(int down)
    Removes the value the given number of elements below the top of the stack.
    void
    push(int down, V value)
    Inserts the given value a given number of elements below the current top of the stack.
    void
    push(V value)
    Pushes the given value onto the stack.
    void
    pushAll(Iterable<V> values)
    Pushes all given elements onto the stack (in the order as given).
    void
    pushAll(V firstValue, V... moreValues)
    Pushes all given elements onto the stack (in the order as given).
    void
    restoreSnapshot(Object snapshot)
    Restores the stack state as previously returned by ValueStack.takeSnapshot().
    int
    size()
    Returns the number of elements currently on the stack.
    void
    swap()
    Swaps the top two stack values.
    void
    swap3()
    Reverses the order of the top 3 stack values.
    void
    swap4()
    Reverses the order of the top 4 stack values.
    void
    swap5()
    Reverses the order of the top 5 stack values.
    void
    swap6()
    Reverses the order of the top 5 stack values.
    Object
    takeSnapshot()
    Returns an object representing the current state of the stack.

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    Methods inherited from interface java.lang.Iterable

    forEach, spliterator

  • Constructor Details

    • DefaultValueStack

      public DefaultValueStack()
      Initializes an empty value stack.

    • DefaultValueStack

      public DefaultValueStack(Iterable<V> values)
      Initializes a value stack containing the given values with the last value being at the top of the stack.
      Parameters:
      values - the initial stack values

  • Method Details

    • isEmpty

      public boolean isEmpty()
      Description copied from interface: ValueStack
      Determines whether the stack is empty.
      Specified by:
      isEmpty in interface ValueStack<V>
      Returns:
      true if empty

    • size

      public int size()
      Description copied from interface: ValueStack
      Returns the number of elements currently on the stack.
      Specified by:
      size in interface ValueStack<V>
      Returns:
      the number of elements

    • clear

      public void clear()
      Description copied from interface: ValueStack
      Clears all values.
      Specified by:
      clear in interface ValueStack<V>

    • takeSnapshot

      public Object takeSnapshot()
      Description copied from interface: ValueStack
      Returns an object representing the current state of the stack. This cost of running this operation is negligible and independent from the size of the stack.
      Specified by:
      takeSnapshot in interface ValueStack<V>
      Returns:
      an object representing the current state of the stack

    • restoreSnapshot

      public void restoreSnapshot(Object snapshot)
      Description copied from interface: ValueStack
      Restores the stack state as previously returned by ValueStack.takeSnapshot(). This cost of running this operation is negligible and independent from the size of the stack.
      Specified by:
      restoreSnapshot in interface ValueStack<V>
      Parameters:
      snapshot - a snapshot object previously returned by ValueStack.takeSnapshot()

    • push

      public void push(V value)
      Description copied from interface: ValueStack
      Pushes the given value onto the stack. Equivalent to push(0, value).
      Specified by:
      push in interface ValueStack<V>
      Parameters:
      value - the value

    • push

      public void push(int down, V value)
      Description copied from interface: ValueStack
      Inserts the given value a given number of elements below the current top of the stack.
      Specified by:
      push in interface ValueStack<V>
      Parameters:
      down - the number of elements to skip before inserting the value (0 being equivalent to push(value))
      value - the value

    • pushAll

      public void pushAll(V firstValue, V... moreValues)
      Description copied from interface: ValueStack
      Pushes all given elements onto the stack (in the order as given).
      Specified by:
      pushAll in interface ValueStack<V>
      Parameters:
      firstValue - the first value
      moreValues - the other values

    • pushAll

      public void pushAll(Iterable<V> values)
      Description copied from interface: ValueStack
      Pushes all given elements onto the stack (in the order as given).
      Specified by:
      pushAll in interface ValueStack<V>
      Parameters:
      values - the values

    • pop

      public V pop()
      Description copied from interface: ValueStack
      Removes the value at the top of the stack and returns it.
      Specified by:
      pop in interface ValueStack<V>
      Returns:
      the current top value

    • pop

      public V pop(int down)
      Description copied from interface: ValueStack
      Removes the value the given number of elements below the top of the stack.
      Specified by:
      pop in interface ValueStack<V>
      Parameters:
      down - the number of elements to skip before removing the value (0 being equivalent to pop())
      Returns:
      the value

    • peek

      public V peek()
      Description copied from interface: ValueStack
      Returns the value at the top of the stack without removing it.
      Specified by:
      peek in interface ValueStack<V>
      Returns:
      the current top value

    • peek

      public V peek(int down)
      Description copied from interface: ValueStack
      Returns the value the given number of elements below the top of the stack without removing it.
      Specified by:
      peek in interface ValueStack<V>
      Parameters:
      down - the number of elements to skip (0 being equivalent to peek())
      Returns:
      the value

    • poke

      public void poke(V value)
      Description copied from interface: ValueStack
      Replaces the current top value with the given value. Equivalent to poke(0, value).
      Specified by:
      poke in interface ValueStack<V>
      Parameters:
      value - the value

    • poke

      public void poke(int down, V value)
      Description copied from interface: ValueStack
      Replaces the element the given number of elements below the current top of the stack.
      Specified by:
      poke in interface ValueStack<V>
      Parameters:
      down - the number of elements to skip before replacing the value (0 being equivalent to poke(value))
      value - the value to replace with

    • dup

      public void dup()
      Description copied from interface: ValueStack
      Duplicates the top value. Equivalent to push(peek()).
      Specified by:
      dup in interface ValueStack<V>

    • swap

      public void swap()
      Description copied from interface: ValueStack
      Swaps the top two stack values.
      Specified by:
      swap in interface ValueStack<V>

    • swap3

      public void swap3()
      Description copied from interface: ValueStack
      Reverses the order of the top 3 stack values.
      Specified by:
      swap3 in interface ValueStack<V>

    • swap4

      public void swap4()
      Description copied from interface: ValueStack
      Reverses the order of the top 4 stack values.
      Specified by:
      swap4 in interface ValueStack<V>

    • swap5

      public void swap5()
      Description copied from interface: ValueStack
      Reverses the order of the top 5 stack values.
      Specified by:
      swap5 in interface ValueStack<V>

    • swap6

      public void swap6()
      Description copied from interface: ValueStack
      Reverses the order of the top 5 stack values.
      Specified by:
      swap6 in interface ValueStack<V>

    • iterator

      public Iterator<V> iterator()
      Specified by:
      iterator in interface Iterable<V>