Package elan.parser.token

The token (parser sub) package holds all token classes.

See:
Description

Interface Summary

Token

currently this is a flag interface

Class Summary

AddToken
AndToken
AssignmentToken
BackgroundToken
BackToken
BgToken
BkToken
CharToken	A token represented by a single character, e.g., '*', ';', '[' and so on; the method equals compares a CharToken as equal to another CharToken encapsulating the same character.
CharTokenFactory	Factory for generating CharToken objects ensuring that only one of any specific CharToken object is created (enforcing CharToken singleton-ness per char value)
CleanToken
ClearscreenToken
CsToken
DifferenceToken
EOFToken	This represents an end-of-file token Uses the singleton pattern since there's no reason to have more than one such token.
EOLToken	This represents an end-of-line token Uses the singleton pattern since there's no reason to have more than one such token.
EqualboolToken
EqualToken
FdToken
FenceToken
ForwardToken
GreaterToken
HeadingToken
HideturtleToken
HomeToken
HtToken
IdentifierToken
IfToken
LeftBracketToken
LeftParenToken
LeftToken
LessToken
LtToken
MinusToken
NotequalToken
NotToken
NumberToken	Represents a number (using doublevalues).
OrToken
PcToken
PdToken
PencolorToken
PendownpToken
PendownqToken
PendownToken
PensizeToken
PenupToken
PlusToken
PrintToken
ProductToken
PsToken
PuToken
QuotientToken
RandomnumToken
RemainderToken
RepeatToken
ReservedToken
RightBracketToken
RightParenToken
RightToken
RtToken
SetbackgroundToken
SetbgToken
SetheadingToken
SethToken
SetpaletteToken
SetpcToken
SetpencolorToken
SetpensizeToken
SetpsToken
SetshapeToken
SetshToken
SetxToken
SetxyToken
SetyToken
ShapeToken
ShowturtleToken
SlashToken
StarToken
StToken
SumToken
TellToken
TokenFactory
ToToken
TowardsToken
VariableToken
WindowToken
WrapToken
XcorToken
YcorToken

Package elan.parser.token Description

The token (parser sub) package holds all token classes. Each token in the language should be represented by a class. Some token classes represent a class of tokens, e.g., CharToken (and its supporting class CharTokenFactory) while others represent individual tokens, e.g., LeftParenToken.

The general contract of a Token sub-class requires implementing equals so that the parser can determine which token is being processed.

Owen L. Astrachan

Last modified: Wed Nov 28 13:11:54 EST 2001