ptolemy.cg.lib.syntactic

Class SyntacticContraction

java.lang.Object

ptolemy.cg.lib.syntactic.SyntacticContraction

All Implemented Interfaces:

SyntacticTerm

public class SyntacticContraction
extends java.lang.Object
implements SyntacticTerm

This class represents a contraction operator in the SyntacticTerm language. It represents the operation of contracting a SyntacticTerm with m inputs and n outputs along the first k of each, where k is a parameter of the operator called degree in the class. The result is a term (as an interface) with m-k inputs and n-k outputs. The operand term being contracted is the kernel of the operator and is referred to by the class as such. The initial object, without a kernel, can be understood to be an operator. Once the kernel is set, the object can be reasonably treated as a syntactic term representing the operator acting on the kernel.

Since:

Ptolemy II 10.0

Version:

$Id$

Author:

Chris Shaver

Pt.AcceptedRating:

Red

Pt.ProposedRating:

Red (shaver)

Constructor Summary

Constructors

Constructor and Description
SyntacticContraction(int degree) Makes a new contraction operator with a given constant degree.

Method Summary

Modifier and Type	Method and Description
int	degree() Get the degree of the term.
java.lang.String	generateCode() Generate the lexical representation of the contraction.
java.util.List<SyntacticPort>	getInputs() Get a list of the input ports to the operator.
int	getOrder() Get the sort order of the term.
java.util.List<SyntacticPort>	getOutputs() Get a list of output ports to the operator.
boolean	hasCode() Decide whether code can be generated from this term.
java.lang.Integer	inputIndex(SyntacticPort port) Get the index of an input port given a reference to it.
SyntacticTerm	kernel() Get the reference to the kernel of the operator.
java.lang.Integer	outputIndex(SyntacticPort port) Get the index of an output port given a reference to it.
SyntacticRank	rank() Get the rank of the term.
boolean	setKernel(SyntacticTerm term) Set the kernel of the operator, effectively making it a term.
int	sizeInputs() Get the number of inputs to the term.
int	sizeOutputs() Get the number of outputs from the term.

Methods inherited from class java.lang.Object

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

Constructor Detail

SyntacticContraction

public SyntacticContraction(int degree)

Makes a new contraction operator with a given constant degree. The degree is the number of outputs of the kernel that will be connected (enumerated ascending) to corresponding inputs.

Parameters:

degree - Degree of the operator.

Method Detail

getInputs

public java.util.List<SyntacticPort> getInputs()

Get a list of the input ports to the operator. If there is no kernel null is returned.

Specified by:

getInputs in interface SyntacticTerm

Returns:

list of input ports.

getOutputs

public java.util.List<SyntacticPort> getOutputs()

Get a list of output ports to the operator. If there is no kernel null is returned.

Specified by:

getOutputs in interface SyntacticTerm

Returns:

list of output ports.

sizeInputs

public int sizeInputs()

Get the number of inputs to the term.

Specified by:

sizeInputs in interface SyntacticTerm

Returns:

number of inputs or zero if no kernel.

sizeOutputs

public int sizeOutputs()

Get the number of outputs from the term.

Specified by:

sizeOutputs in interface SyntacticTerm

Returns:

number of outputs or zero if no kernel.

rank

public SyntacticRank rank()

Get the rank of the term.

Specified by:

rank in interface SyntacticTerm

Returns:

rank of term.

inputIndex

public java.lang.Integer inputIndex(SyntacticPort port)

Get the index of an input port given a reference to it. null is returned if the port does not exist in the term or the kernel is absent.

Specified by:

inputIndex in interface SyntacticTerm

Parameters:

port - Port to find the index of.

Returns:

the index of the port or null if none.

outputIndex

public java.lang.Integer outputIndex(SyntacticPort port)

Get the index of an output port given a reference to it. null is returned if the port does not exist in the term or the kernel is absent.

Specified by:

outputIndex in interface SyntacticTerm

Parameters:

port - Port to find the index of.

Returns:

the index of the port or null if none.

setKernel

public boolean setKernel(SyntacticTerm term)

Set the kernel of the operator, effectively making it a term. Once the kernel is set, the class can be understood via the SyntacticTerm interface to be the term constituted of the kernel operated on by the contraction. If the rank is larger than the number of contractions that can happen on the kernel, it is not set and false is returned.

Parameters:

term - Term to contract with operator.

Returns:

whether kernel was set.

generateCode

public java.lang.String generateCode()

Generate the lexical representation of the contraction. The generation of code recursively descends to generate the code corresponding to the kernel. The operator is notated: { degree : kernel code }

Specified by:

generateCode in interface SyntacticTerm

Returns:

lexical representation of term.

getOrder

public int getOrder()

Get the sort order of the term.

Specified by:

getOrder in interface SyntacticTerm

Returns:

sort order of the term.

hasCode

public boolean hasCode()

Decide whether code can be generated from this term.

Specified by:

hasCode in interface SyntacticTerm

Returns:

whether code can be generated.

kernel

public SyntacticTerm kernel()

Get the reference to the kernel of the operator.

Returns:

kernel of the operator.

degree

public int degree()

Get the degree of the term.

Returns:

degree of term.