Package elan.expression

Represents standard infix (mathematical) expressions.

See:
          Description

Class Summary
Addition Represents a + b, the addition of two expressions
And Represents a + b, the addition of two expressions
Background  
Bg  
BinaryExpression The base class of any binary expression, e.g., a + b, a - b, or, in future use, a < b and so on.
Difference Represents a + b, the addition of two expressions
Division  
Equalbool Returns true if a = b, false otherwise
Expression the base class of all arithmetic expressions, the evaluate method uses the hook/template method value to return a Double value, the template method returns a double.
Greater Represents a + b, the addition of two expressions
Heading Returns heading of turtle
Less Returns true if a is less than b, false otherwise
Minus Represents -a, the negation of an expression
Multiplication Represents a x b, the multiplication of two expressions
Negation Represents unary minus, e.g., -expression
Not Represents a + b, the addition of two expressions
Notequal Returns true if a is not equal to b, false otherwise
Number  
Or Represents a + b, the addition of two expressions
Pc  
Pencolor  
Pendownp Represents a + b, the addition of two expressions
Pensize  
Product Represents a * b, the product of two expressions
Ps  
Quotient Represents a / b, the quotient of two expressions
Randomnum Represents a + b, the addition of two expressions
Remainder Represents a % b, the remainder from the divison of two expressions
Shape  
Subtraction  
Sum Represents a + b, the addition of two expressions
Towards Returns heading required for turtle to point from current location to specified point.
UnaryExpression  
Variable A variable stores a value and can be used in an expression.
VariableFactory Clients can use this class to obtain a unique variable per identifier (avoiding a proliferation of objects)
Xcor  
Ycor  
 

Package elan.expression Description

Represents standard infix (mathematical) expressions. This package exports elan.expression.Expression, a subclass of GrammarElement representing arithmetic expressions like plus, times, minus (binary expressions) and variables. It can easily be extended to represent boolean expressions.


Owen L. Astrachan
Last modified: Wed Nov 28 13:14:55 EST 2001