escjava.prover
Class SPair

java.lang.Object
  escjava.prover.SExp
      escjava.prover.SList
          escjava.prover.SPair

class SPair

extends SList

A SPair is a pair of a SExp and a SList; together with the SNil class, it is used to implement lists of SExps.

Considered as SLists, SPairs always represent non-empty lists.

Field Summary

SExp	head The head of our list; this field should not be modified by clients and should be non-null.
SList	tail The tail of our list; this field should not be modified by clients and should be non-null.

Constructor Summary

SPair(SExp head, SList tail)
Return a new list with given head and tail.

Method Summary

boolean	equals(java.lang.Object o) Return true if the heads are equal and the tails are equal.
(package private) SPair	getPair() If we represent a non-empty list, return it as a SPair; otherwise, throw SExpTypeError.
boolean	isEmpty() Are we an empty list?
int	length() Return our length

Methods inherited from class escjava.prover.SList

addEnd, addFront, append, at, fromArray, getList, isList, main, make, make, make, make, make, make, make, make, make, prettyPrint, print, reverseD, setAt

Methods inherited from class escjava.prover.SExp

display, fancyMake, getAtom, getInteger, isAtom, isInteger, make, print, toString

Methods inherited from class java.lang.Object

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

Field Detail

head

public SExp head

The head of our list; this field should not be modified by clients and should be non-null.

tail

public SList tail

The tail of our list; this field should not be modified by clients and should be non-null.

Constructor Detail

SPair

public SPair(SExp head,
             SList tail)

Return a new list with given head and tail.

Both must be non-null.

Method Detail

isEmpty

public boolean isEmpty()

Are we an empty list?

Specified by:

isEmpty in class SList

Returns:

a flag indicating if we are we an empty list.

getPair

SPair getPair()

If we represent a non-empty list, return it as a SPair; otherwise, throw SExpTypeError.

Overrides:

getPair in class SList

length

public int length()

Return our length

Specified by:

length in class SList

Returns:

our length.

equals

public boolean equals(java.lang.Object o)

Return true if the heads are equal and the tails are equal.