Class GroupingSymbol

java.lang.Object
  |
  +--GroupingSymbol

public class GroupingSymbol

extends java.lang.Object

This class represents a grouping symbol in an equation. Grouping symbols are used to change the order in which an infix equation is solved. Normally an equation is solved it is solved left to right and according to the order of operations. Grouping symbols allow one to specify that certain operations which would normally occur later in the solving can occur earlier.

Parentheses are common grouping symbols for instance. The use of parentheses allows one to change the meaning of 3 + 4 / 14 from 3 2/7 to (3 + 4) / 14 which is 7.

I am thinking that no further explanation is needed. This should have been covered in fifth grade or so.

Field Summary

java.lang.String	closeToken Symbol representing that a group has been closed
boolean	openingSymbol flag telling whether or not this particular symbol instance was an open or a close
java.lang.String	openToken Symbol representing that a group has been begun

Constructor Summary

GroupingSymbol(java.lang.String o, java.lang.String c)
Calls GroupingSymbol(String, String, boolean) with a default of the symbol being an opening symbol.

GroupingSymbol(java.lang.String o, java.lang.String c, boolean opening)
A GroupingSymbol is created not simply with the actual token that it represents but also the close for that symbol.

Method Summary

boolean	isAClosingSymbol() Tells if the current symbol represents the close of a group
boolean	isAnOpeningSymbol() Tells if the current symbol represents the beginning of a group
boolean	isCloseFor(GroupingSymbol o) Tells whether o is the opposing symbol for this symbol.
java.lang.String	token() Returns the appropriate token representing this grouping symbol.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

openToken

public java.lang.String openToken

Symbol representing that a group has been begun

closeToken

public java.lang.String closeToken

Symbol representing that a group has been closed

openingSymbol

public boolean openingSymbol

flag telling whether or not this particular symbol instance was an open or a close

Constructor Detail

GroupingSymbol

public GroupingSymbol(java.lang.String o,
                      java.lang.String c)

Calls GroupingSymbol(String, String, boolean) with a default of the symbol being an opening symbol.

Parameters:

o - the opening symbol

c - the closing symbol

GroupingSymbol

public GroupingSymbol(java.lang.String o,
                      java.lang.String c,
                      boolean opening)

A GroupingSymbol is created not simply with the actual token that it represents but also the close for that symbol. This is done because a grouping symbol is worthless unless its close is known.

Parameters:

o - the opening symbol

c - the closing symbol

opening - flag telling whether this particular symbol represents the open or the close for this pair

Method Detail

isCloseFor

public boolean isCloseFor(GroupingSymbol o)

Tells whether o is the opposing symbol for this symbol.

Parameters:

o - the grouping symbol to be checked against

token

public java.lang.String token()

Returns the appropriate token representing this grouping symbol. If the symbol is an open then openToken is returned otherwise closeToken is returned.

Returns:

the token for the current symbol

toString

public java.lang.String toString()

Returns:

returns the value of token()

Overrides:

toString in class java.lang.Object

isAnOpeningSymbol

public boolean isAnOpeningSymbol()

Tells if the current symbol represents the beginning of a group

Returns:

true if the symbol begins a group

isAClosingSymbol

public boolean isAClosingSymbol()

Tells if the current symbol represents the close of a group

Returns:

true if the symbol closes a group