io.druid.sql.calcite.expression

Class ExtractionFns

java.lang.Object

io.druid.sql.calcite.expression.ExtractionFns

public class ExtractionFns
extends Object

Constructor Summary

Constructors

Constructor and Description
ExtractionFns()

Method Summary

Modifier and Type	Method and Description
static ExtractionFn	cascade(ExtractionFn f, ExtractionFn g) Cascade f and g, returning an ExtractionFn that computes g(f(x)).
static ExtractionFn	fromQueryGranularity(Granularity queryGranularity) Converts a QueryGranularity to an extractionFn, if possible.
static Granularity	toQueryGranularity(ExtractionFn extractionFn) Converts extractionFn to a QueryGranularity, if possible.

Methods inherited from class java.lang.Object

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

Constructor Detail

ExtractionFns

public ExtractionFns()

Method Detail

toQueryGranularity

public static Granularity toQueryGranularity(ExtractionFn extractionFn)

Converts extractionFn to a QueryGranularity, if possible. This is the inverse of fromQueryGranularity(Granularity).

Parameters:

extractionFn - function

Returns:

query granularity, or null if extractionFn cannot be translated

fromQueryGranularity

public static ExtractionFn fromQueryGranularity(Granularity queryGranularity)

Converts a QueryGranularity to an extractionFn, if possible. This is the inverse of toQueryGranularity(ExtractionFn). This will always return a non-null extractionFn if queryGranularity is non-null.

Parameters:

queryGranularity - granularity

Returns:

extractionFn, or null if queryGranularity is null

cascade

public static ExtractionFn cascade(ExtractionFn f,
                                   ExtractionFn g)

Cascade f and g, returning an ExtractionFn that computes g(f(x)). Null f or g are treated like identity functions.

Parameters:

f - function

g - function

Returns:

composed function, or null if both f and g were null