org.scijava.parsington

Class Operator

java.lang.Object

org.scijava.parsington.Token

org.scijava.parsington.Operator

All Implemented Interfaces:

Comparable<Operator>

Direct Known Subclasses:

Function, Group

public class Operator
extends Token
implements Comparable<Operator>

A mathematical operator is a special symbol or "verb" which defines a relation between "nouns" (i.e.: literals and variables). For binary operators, it is infix (between the nouns); for unary operators, it is either prefix (preceding the noun) or postfix (following the noun).

Author:

Curtis Rueden

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Operator.Associativity

Constructor Summary

Constructors

Constructor and Description
Operator(String symbol, int arity, Operator.Associativity associativity, double precedence)

Method Summary

Modifier and Type	Method and Description
int	compareTo(Operator that)
int	getArity() Gets the operator's arity.
Operator.Associativity	getAssociativity() Gets the operator's associativity.
double	getPrecedence() Gets the operator precedence.
Operator	instance() Gets an instance of the operator, using this one as a template.
boolean	isInfix() Gets whether the operator is an infix operator (e.g., a-b).
boolean	isLeftAssociative() Gets whether the operator is left associative.
boolean	isPostfix() Gets whether the operator is a postfix operator (e.g., a').
boolean	isPrefix() Gets whether the operator is a prefix operator (e.g., -a).
boolean	isRightAssociative() Gets whether the operator is right associative.

Methods inherited from class org.scijava.parsington.Token

getToken, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

Operator

public Operator(String symbol,
                int arity,
                Operator.Associativity associativity,
                double precedence)

Method Detail

getArity

public int getArity()

Gets the operator's arity.

Returns:

The arity of the operator: 1 for unary, 2 for binary, etc.

getAssociativity

public Operator.Associativity getAssociativity()

Gets the operator's associativity.

Returns:

One of Operator.Associativity.EITHER, Operator.Associativity.LEFT, Operator.Associativity.RIGHT, or Operator.Associativity.NONE.

isLeftAssociative

public boolean isLeftAssociative()

Gets whether the operator is left associative.

Returns:

True iff the operator's associativity is Operator.Associativity.LEFT or Operator.Associativity.EITHER.

isRightAssociative

public boolean isRightAssociative()

Gets whether the operator is right associative.

Returns:

True iff the operator's associativity is Operator.Associativity.RIGHT or Operator.Associativity.EITHER.

isInfix

public boolean isInfix()

Gets whether the operator is an infix operator (e.g., a-b).

Returns:

True iff the operator is an infix operator.

isPrefix

public boolean isPrefix()

Gets whether the operator is a prefix operator (e.g., -a).

Returns:

True iff the operator is a prefix operator.

isPostfix

public boolean isPostfix()

Gets whether the operator is a postfix operator (e.g., a').

Returns:

True iff the operator is a postfix operator.

getPrecedence

public double getPrecedence()

Gets the operator precedence. Larger is higher.

Returns:

The operator precedence.

instance

public Operator instance()

Gets an instance of the operator, using this one as a template.

For stateless operators, no copy will be made. But for operators with state (e.g. Group), a new instance will be returned.

Returns:

this or a new instance, depending on the type of operator.

compareTo

public int compareTo(Operator that)

Specified by:

compareTo in interface Comparable<Operator>