slogo.instruction.arithmetic
Class Subtraction

java.lang.Object
  slogo.language.GrammarElement
      slogo.instruction.Instruction
          slogo.instruction.arithmetic.NumericInstruction
              slogo.instruction.arithmetic.ArithmeticInstruction
                  slogo.instruction.arithmetic.Subtraction

public class Subtraction
extends ArithmeticInstruction

Represents a - b, the subtraction of two expressions

Field Summary

Fields inherited from class slogo.instruction.arithmetic.ArithmeticInstruction

myLeft, myRight, mySymbol

Fields inherited from class slogo.language.GrammarElement

gelementsToValue

Constructor Summary

Subtraction(GrammarElement firstElem, GrammarElement secondElem)

Method Summary

java.lang.Double

evaluate(Context c) Evaluate this language construct in some context.

Methods inherited from class slogo.instruction.arithmetic.ArithmeticInstruction

leftValue, rightValue, toString

Methods inherited from class slogo.instruction.Instruction

evaluateNumericExpression

Methods inherited from class java.lang.Object

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

Constructor Detail

Subtraction

public Subtraction(GrammarElement firstElem,
                   GrammarElement secondElem)

Method Detail

evaluate

public java.lang.Double evaluate(Context c)

Description copied from class: GrammarElement

Evaluate this language construct in some context. The evaluation may have side-effects, e.g., moving a turtle.

Specified by:

evaluate in class NumericInstruction

Parameters:

c - context in which the evaluation takes place

Returns:

the result of evaluating the construct