com.rubecula.jquantity
Class Mill

java.lang.Object
  |
  +--java.util.AbstractCollection
        |
        +--java.util.AbstractList
              |
              +--java.util.Vector
                    |
                    +--java.util.Stack
                          |
                          +--com.rubecula.jquantity.Mill

All Implemented Interfaces:

Auditable, java.lang.Cloneable, java.util.Collection, java.util.List, Lookupable, Millable, java.util.RandomAccess, java.io.Serializable

Direct Known Subclasses:

Mill

public class Mill

extends java.util.Stack

implements Millable

This class is responsible for evaluating operations on Presentable objects. It is named in honor of Charles Babbage, and not forgetting the early days of computing, especially in the United Kingdom, and paricularly for Maurice Wilkes.

Version:

$Revision: 1.12 $

Author:

Robin Hillyard

See Also:

Serialized Form

Nested Class Summary

Nested classes inherited from class java.util.AbstractList

Field Summary

protected static java.lang.String	OP_2ATAN
protected static java.lang.String	OP_AUDIT
protected static java.lang.String	OP_CHS
protected static java.lang.String	OP_COPY
protected static java.lang.String	OP_DIFFERENCE
protected static java.lang.String	OP_E
protected static java.lang.String	OP_EXP
protected static java.lang.String	OP_INV
protected static java.lang.String	OP_LOG
protected static java.lang.String	OP_NOOP
protected static java.lang.String	OP_PI
protected static java.lang.String	OP_POWER
protected static java.lang.String	OP_PRODUCT
protected static java.lang.String	OP_QUOTIENT
protected static java.lang.String	OP_SUM
protected static java.lang.String	OP_SWAP
protected static java.lang.String	OP_TANHALF

Fields inherited from class java.util.Vector

capacityIncrement, elementCount, elementData

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Mill(java.lang.String name)
Principal constructor for a new Mill.

Method Summary

java.lang.String	audit() Method to return a detailed (unlabeled) string from an object for debugging purposes.
void	audit(java.io.PrintStream out, java.lang.String label) Method to output detailed string from an object for debugging purposes.
java.lang.String	audit(java.lang.String label) Method to return a detailed string from an object for debugging purposes.
int	getAdy(java.lang.String operator) This method returns the number of presentables needed to popped off the stack for an operation.
java.lang.String	getIdentifier() Method to get the specific identifier for an object.
AlphabeticalMap	getOperations() Method to get a map which represents the supported functions of this Mill.
Presentable	getValue(java.lang.String key) Method to get a memory presentable defined by key.
void	help(java.io.PrintStream output) This method outputs help information listing and describing the various operations supported by the mill.
static void	main(java.lang.String[] args) Main method for testing this class.
void	operate(java.lang.String operator) Mutating method to apply the operation operator to the stack.
void	push(Presentable operand) Mutating method to push operand onto the top of the Mill stack.
void	setValue(java.lang.String key, Presentable value) Method to set a value which can later be retrieved using the name given (using the method defined by the Lookupable interface).

Methods inherited from class java.util.Stack

empty, peek, pop, push, search

Methods inherited from class java.util.Vector

add, add, addAll, addAll, addElement, capacity, clear, clone, contains, containsAll, copyInto, elementAt, elements, ensureCapacity, equals, firstElement, get, hashCode, indexOf, indexOf, insertElementAt, isEmpty, lastElement, lastIndexOf, lastIndexOf, remove, remove, removeAll, removeAllElements, removeElement, removeElementAt, removeRange, retainAll, set, setElementAt, setSize, size, subList, toArray, toArray, toString, trimToSize

Methods inherited from class java.util.AbstractList

iterator, listIterator, listIterator

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.rubecula.util.Millable

pop, size

Methods inherited from interface java.util.List

iterator, listIterator, listIterator

Field Detail

OP_SUM

protected static final java.lang.String OP_SUM

See Also:

Constant Field Values

OP_DIFFERENCE

protected static final java.lang.String OP_DIFFERENCE

See Also:

Constant Field Values

OP_PRODUCT

protected static final java.lang.String OP_PRODUCT

See Also:

Constant Field Values

OP_QUOTIENT

protected static final java.lang.String OP_QUOTIENT

See Also:

Constant Field Values

OP_POWER

protected static final java.lang.String OP_POWER

See Also:

Constant Field Values

OP_2ATAN

protected static final java.lang.String OP_2ATAN

See Also:

Constant Field Values

OP_TANHALF

protected static final java.lang.String OP_TANHALF

See Also:

Constant Field Values

OP_EXP

protected static final java.lang.String OP_EXP

See Also:

Constant Field Values

OP_LOG

protected static final java.lang.String OP_LOG

See Also:

Constant Field Values

OP_CHS

protected static final java.lang.String OP_CHS

See Also:

Constant Field Values

OP_INV

protected static final java.lang.String OP_INV

See Also:

Constant Field Values

OP_PI

protected static final java.lang.String OP_PI

See Also:

Constant Field Values

OP_E

protected static final java.lang.String OP_E

See Also:

Constant Field Values

OP_COPY

protected static final java.lang.String OP_COPY

See Also:

Constant Field Values

OP_AUDIT

protected static final java.lang.String OP_AUDIT

See Also:

Constant Field Values

OP_SWAP

protected static final java.lang.String OP_SWAP

See Also:

Constant Field Values

OP_NOOP

protected static final java.lang.String OP_NOOP

See Also:

Constant Field Values

Constructor Detail

Mill

public Mill(java.lang.String name)

Principal constructor for a new Mill.

Parameters:

name - by which this Mill will be referred to.

Method Detail

push

public void push(Presentable operand)
          throws MillException

Mutating method to push operand onto the top of the Mill stack.

Specified by:

push in interface Millable

Parameters:

operand - a presentable object which will displace the former top of the stack to the second position and itself become the top object.

Throws:

MillException - operand not a BaseNumber.

operate

public void operate(java.lang.String operator)
             throws java.util.EmptyStackException,
                    MillException

Mutating method to apply the operation operator to the stack. The number of items required on the stack prior to the operation and the number of items left on the stack afterwards depends upon the operation.

Specified by:

operate in interface Millable

Parameters:

operator - the name for the operation. The following operators ONLY are supported by this Mill:

$name

Retrieve the value indicated by name and push it on the stack. Note that such values are first looked up in the constants list and then, if nothing is found, in the instance list.

<blank>

Pop one value from the stack and push it back.

swap

Reverse the order of the two top stack items.

copy

Pop the top item off the stack and push it back twice.

+

Pop two values from the stack and push their sum.

-

Pop two values from the stack and push their difference.

*

Pop two values from the stack and push their product.

/

Pop two values from the stack and push their quotient.

inv

Pop one value from the stack, take its reciprocal and push the result.

chs

Pop one value from the stack, change its sign and push the result.

log

Pop one value from the stack, take its natural logarithm and push the result.

exp

Pop one value from the stack, raise e to its power and push the result.

2atan

Pop one value from the stack, evaluate twice the arctangent and push the result.

tanhalf

Pop one value from the stack, evaluate the tangent of half the value and push the result.

Throws:

java.util.EmptyStackException

MillException

getValue

public Presentable getValue(java.lang.String key)

Method to get a memory presentable defined by key. The lookup is first made in the class constants and then, if that fails, in this instance's memory. In this way, constants cannot be replaced either deliberately or inadvertently.

Specified by:

getValue in interface Lookupable

Parameters:

key - the name of the memory object, without any preceding "$".

Returns:

the presentable value specified or null.

setValue

public void setValue(java.lang.String key,
                     Presentable value)
              throws MillException

Method to set a value which can later be retrieved using the name given (using the method defined by the Lookupable interface). A memory value can be unset by setting to the null value. Names which appear in the constants list cannot be reused.

Specified by:

setValue in interface Millable

Parameters:

key - the name or key by which this value can be retrieved (without any preceding "$").

value - a Presentable value which is lookupable.

Throws:

MillException - if memory slot name cannot be set to value, because the name is already in use (or an attempt to remove a constant).

getOperations

public AlphabeticalMap getOperations()

Method to get a map which represents the supported functions of this Mill. The keys are the operators (typically abbreviations, all lower case) and the entries are the full mathematical function names (all lower case).

Specified by:

getOperations in interface Millable

Returns:

a map of the abbreviation-function mappings for the supported operations of this mill.

help

public void help(java.io.PrintStream output)

This method outputs help information listing and describing the various operations supported by the mill.

Specified by:

help in interface Millable

Parameters:

output - an output stream.

getIdentifier

public java.lang.String getIdentifier()

Method to get the specific identifier for an object.

Specified by:

getIdentifier in interface Auditable

Returns:

the identifier.

audit

public java.lang.String audit(java.lang.String label)

Method to return a detailed string from an object for debugging purposes.

Specified by:

audit in interface Auditable

Parameters:

label - the label to associate with the data. If label is non-null, a more detailed audit will be returned (this normally occurs only at the top level).

Returns:

the detailed string.

audit

public java.lang.String audit()

Method to return a detailed (unlabeled) string from an object for debugging purposes.

Specified by:

audit in interface Auditable

Returns:

the detailed string.

audit

public void audit(java.io.PrintStream out,
                  java.lang.String label)

Method to output detailed string from an object for debugging purposes.

Specified by:

audit in interface Auditable

Parameters:

out - the output stream.

label - the label to attach to the output (may be null).

getAdy

public int getAdy(java.lang.String operator)
           throws MillException

This method returns the number of presentables needed to popped off the stack for an operation.

Specified by:

getAdy in interface Millable

Parameters:

operator - the name (abbreviation) of the operator.

Returns:

0, 1 or 2 for an-, mon- or dy-adic operators; special operators that don't make a net change in the stack at all return -1.

Throws:

MillException - operator is not supported.

main

public static void main(java.lang.String[] args)

Main method for testing this class.

Parameters:

args - String[] : the command line options.