uk.ac.starlink.vo

Class AdqlFeature

java.lang.Object

uk.ac.starlink.vo.AdqlFeature

Direct Known Subclasses:

AdqlFeature.Function

public class AdqlFeature
extends Object

Describes a documented language feature that can be used in some variant of the ADQL language.

A number of static methods are provided that return lists of features provided by a particular ADQL version either absolutely or in the context of a list of language feature declarations. This class contains knowledge about what standard mandatory and optional features are declared by known versions of the ADQL standard.

Note that ADQL 2.0 does not define a proper type system, so in the case of ADQL 2.0 the types declared here are not strictly based in the standard, but a casual reading will give the intent of what was written in the ADQL 2.0 standard.

Since:

23 Feb 2024

Author:

Mark Taylor

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AdqlFeature.Arg Represents a declared argument of a function.
static class	AdqlFeature.Function AdqlFeature subclass which represents a function.
static class	AdqlFeature.Type Datatype of a function argument or return value.

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.function.Predicate<Ivoid>	ADQL21MISC_FILTER Includes feature types for Ivoids representing optional features.
static java.util.function.Predicate<Ivoid>	ADQLGEO_FILTER Includes feature types for Ivoids representing Geometry functions.
static java.util.function.Predicate<Ivoid>	NONSTD_FILTER Includes feature types for Ivoids representing non-standard features.
static java.util.function.Predicate<Ivoid>	UDF_FILTER Includes feature types for Ivoids representing UDFs.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AdqlFeature(String name, String description) Constructor.

Method Summary

Modifier and Type	Method and Description
String	getDescription() Returns a plain text description of this feature.
static AdqlFeature.Function[]	getGeomFunctions(AdqlVersion version, TapCapability tcap) Returns an array of the standard ADQL 2.0 or 2.1 geometry functions declared by a given TapCapability object.
static AdqlFeature.Function[]	getMathsFunctions() Returns an array of the maths functions defined by ADQL.
String	getName() Returns the name of this feature.
static AdqlFeature[]	getOptionalFeatures(TapCapability tcap) Returns an array of the ADQL 2.1 optional features (excluding functions) declared by a given TapCapability object.
static AdqlFeature.Function[]	getOptionalFunctions(TapCapability tcap) Returns an array of the ADQL 2.1 optional functions (but not other optional features) declared by a given TapCapability object.
static AdqlFeature.Function[]	getTrigFunctions() Returns an array of the trigonometric functions defined by ADQL.

Methods inherited from class java.lang.Object

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

Field Detail

UDF_FILTER

public static final java.util.function.Predicate<Ivoid> UDF_FILTER

Includes feature types for Ivoids representing UDFs.

ADQLGEO_FILTER

public static final java.util.function.Predicate<Ivoid> ADQLGEO_FILTER

Includes feature types for Ivoids representing Geometry functions.

ADQL21MISC_FILTER

public static final java.util.function.Predicate<Ivoid> ADQL21MISC_FILTER

Includes feature types for Ivoids representing optional features.

NONSTD_FILTER

public static final java.util.function.Predicate<Ivoid> NONSTD_FILTER

Includes feature types for Ivoids representing non-standard features.

Constructor Detail

AdqlFeature

protected AdqlFeature(String name,
                      String description)

Constructor.

Parameters:

name - feature name

description - plain text description directed at users

Method Detail

getName

public String getName()

Returns the name of this feature.

Returns:

function name

getDescription

public String getDescription()

Returns a plain text description of this feature.

Returns:

description

getMathsFunctions

public static AdqlFeature.Function[] getMathsFunctions()

Returns an array of the maths functions defined by ADQL. This is the same for ADQL 2.0 and 2.1, and consists of the contents of Table 1 in Section 2.3 of ADQL 2.1.

Returns:

maths functions

getTrigFunctions

public static AdqlFeature.Function[] getTrigFunctions()

Returns an array of the trigonometric functions defined by ADQL. This is the same for ADQL 2.0 and 2.1 and consists of the contents of Table 2 in Section 2.3 of ADQL 2.1.

Returns:

trig functions

getGeomFunctions

public static AdqlFeature.Function[] getGeomFunctions(AdqlVersion version,
                                                      TapCapability tcap)

Returns an array of the standard ADQL 2.0 or 2.1 geometry functions declared by a given TapCapability object. These are defined in Section 4.2 of ADQL 2.1 and Section 2.4 of ADQL 2.0.

Parameters:

version - ADQL version

tcap - capabilities

Returns:

geometry functions

getOptionalFunctions

public static AdqlFeature.Function[] getOptionalFunctions(TapCapability tcap)

Returns an array of the ADQL 2.1 optional functions (but not other optional features) declared by a given TapCapability object. These are defined in Section 4 of ADQL 2.1.

Parameters:

tcap - capabilities

Returns:

optional functions

getOptionalFeatures

public static AdqlFeature[] getOptionalFeatures(TapCapability tcap)

Returns an array of the ADQL 2.1 optional features (excluding functions) declared by a given TapCapability object. These are defined in Section 4 of ADQL 2.1.

Parameters:

tcap - capabilities

Returns:

optional features