Package com.singularsys.extensions.lambda

Class Signature

java.lang.Object

com.singularsys.extensions.lambda.Signature

Direct Known Subclasses:

Signature.InnerSig, Signature.OuterSig

public abstract sealed class Signature
extends Object
permits Signature.OuterSig, Signature.InnerSig

Represents the signature of a lambda function Either a single variable x, a list of variables [x,y,z] a pattern (u,v) or a list containing variables and patterns [(x1,x2),y]. A nested structure of sub-types are used:

• Signature.OuterSig the top level signature, one of
  • Signature.Vbl for a single variable
  • Signature.ListSig for a list of variables and patterns
• Signature.InnerSig the inner signature, one of
  • Signature.PVbl for a single variable inside a list or pattern
  • Signature.Pat for a pattern

Since:

Jep 4.1, extensions 2.2

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Signature.InnerSig	Inner elements
static final class	Signature.ListSig	A Signature representing a list of signatures
static class	Signature.OuterSig	Outer, top-level elements
static final class	Signature.Pat	A Signature representing a pattern {u,v} .
static final class	Signature.PVbl	A signature representing a single variable inside a list or pattern, e.g.
static final class	Signature.Vbl	A signature representing a single variable.

Constructor Summary

Constructors

Constructor	Description
Signature()

Method Summary

Modifier and Type	Method	Description
protected static Signature.InnerSig	calcInnerSig(Node node, List<String> argList, PostfixMathCommandI listPfmc)
protected static Signature.OuterSig	calcSig(Node node, List<String> argList, PostfixMathCommandI listPfmc)	Calculate the signature and extract variable names.
protected abstract void	calculateArgs(Stack<Object> stack, List<Object> args)	Convert arguments on the stack to a list of arguments matching the pattern in this signature
abstract List<? extends Signature>	getSigs()	Return a list of signatures
abstract boolean	isSimple()	Simple signatures like x or [x,y,z]
protected abstract boolean	match(Object x)
protected abstract boolean	match(Object x, Object y)
abstract boolean	matchN(Object[] args)
abstract int	size()	Number of element in a compound signature

Methods inherited from class java.lang.Object

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

Constructor Details

Signature

public Signature()

Method Details

isSimple

public abstract boolean isSimple()

Simple signatures like x or [x,y,z]

Returns:

true if it is simple

size

public abstract int size()

Number of element in a compound signature

Returns:

number of elements, 1 for variables

calculateArgs

protected abstract void calculateArgs(Stack<Object> stack,
 List<Object> args)
                               throws EvaluationException

Convert arguments on the stack to a list of arguments matching the pattern in this signature

Parameters:

stack - input arguments to the function

args - output list of values matching the variables in the signature

Throws:

EvaluationException - on error

getSigs

public abstract List<? extends Signature> getSigs()

Return a list of signatures

Returns:

either a list or an empty list

match

protected abstract boolean match(Object x)

match

protected abstract boolean match(Object x,
 Object y)

calcSig

protected static Signature.OuterSig calcSig(Node node,
 List<String> argList,
 PostfixMathCommandI listPfmc)
                                     throws EvaluationException

Calculate the signature and extract variable names.

Parameters:

node - specifying the signature, e.g. [[x,y],z]

argList - output list of variable names

listPfmc - the PostfixMathCommandI corresponding to the list operator

Returns:

the signature of the node

Throws:

EvaluationException

calcInnerSig

protected static Signature.InnerSig calcInnerSig(Node node,
 List<String> argList,
 PostfixMathCommandI listPfmc)
                                          throws EvaluationException

Throws:

EvaluationException

matchN

public abstract boolean matchN(Object[] args)