Package jsonvalues

Class MatchExp

java.lang.Object

jsonvalues.MatchExp

public class MatchExp
extends Object

Java doesn't support Pattern Matching but we can implement some matching expressions using high order functions.

Method Summary

Modifier and Type	Method	Description
static Consumer<JsElem>	accept(Consumer<JsElem> ifValue, Consumer<JsObj> ifObj, Consumer<JsArray> ifArray)	Declarative way of consuming an element based on its type
static <T> Function<JsElem,T>	ifArrElse(Function<? super JsArray,T> ifArr, Function<? super JsElem,T> ifNotArr)	return a matching expression to extract arrays out of json elements.
static <T> Function<JsElem,T>	ifBoolElse(Function<? super Boolean,T> ifBoolean, Function<? super JsElem,T> ifNotBoolean)	return a matching expression to extract booleans out of json elements.
static <T> Function<JsElem,T>	ifDecimalElse(DoubleFunction<T> ifDouble, Function<BigDecimal,T> ifBigDecimal, Function<? super JsElem,T> ifOther)	return a matching expression to extract decimal numbers out of json elements.
static <T> Function<JsElem,T>	ifIntegralElse(IntFunction<T> ifInt, LongFunction<T> ifLong, Function<BigInteger,T> ifBigInt, Function<? super JsElem,T> ifOther)	return a matching expression to extract integral numbers out of json elements.
static <T> Function<JsElem,T>	ifJsonElse(Function<? super JsObj,T> ifObj, Function<? super JsArray,T> ifArr, Function<? super JsElem,T> ifValue)	return a matching expression to extract objs and arrays out of json elements.
static <T> Function<JsElem,T>	ifJsonElse(Function<Json<?>,T> ifJson, Function<JsElem,T> ifNotJson)	return a matching expression to extract jsons out of json elements.
static <T> Function<JsElem,T>	ifNothingElse(Supplier<T> nothingSupplier, Function<JsElem,T> elseFn)	return a matching expression to extract JsNothing out of json elements.
static <T> Function<JsElem,T>	ifObjElse(Function<? super JsObj,T> ifObj, Function<? super JsElem,T> ifNotObj)	return a matching expression to extract json objects out of json elements.
static <T> Function<JsElem,T>	ifPredicateElse(Predicate<JsElem> predicate, Function<JsElem,T> ifTrue, Function<JsElem,T> ifFalse)	declarative way of implementing an if-else using high order functions
static <T> Function<JsElem,T>	ifStrElse(Function<? super String,T> ifStr, Function<? super JsElem,T> ifNotStr)	returns a matching expression to extract strings out of json elements.

Methods inherited from class java.lang.Object

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

Method Detail

accept

public static Consumer<JsElem> accept(Consumer<JsElem> ifValue,
                                      Consumer<JsObj> ifObj,
                                      Consumer<JsArray> ifArray)

Declarative way of consuming an element based on its type

Parameters:

ifValue - the consumer to be invoked if this JsElem is a JsValue

ifObj - the consumer to be invoked if this JsElem is a JsObj

ifArray - the consumer to be invoked if this JsElem is a JsArray

Returns:

consumer of a json element

ifArrElse

public static <T> Function<JsElem,T> ifArrElse(Function<? super JsArray,T> ifArr,
                                                     Function<? super JsElem,T> ifNotArr)

return a matching expression to extract arrays out of json elements.

Type Parameters:

T - the type of the object returned

Parameters:

ifArr - the function to be applied if this JsElem is a JsArray

ifNotArr - the function to be applied if this JsElem is not a JsArray

Returns:

a function that takes a JsElem and returns an object of type T

ifBoolElse

public static <T> Function<JsElem,T> ifBoolElse(Function<? super Boolean,T> ifBoolean,
                                                      Function<? super JsElem,T> ifNotBoolean)

return a matching expression to extract booleans out of json elements.

Type Parameters:

T - the type of the object returned

Parameters:

ifBoolean - the function to be applied if this JsElem is a JsBool

ifNotBoolean - the function to be applied if this JsElem is not a JsBool

Returns:

a function that takes a JsElem and returns an object of type T

ifDecimalElse

public static <T> Function<JsElem,T> ifDecimalElse(DoubleFunction<T> ifDouble,
                                                         Function<BigDecimal,T> ifBigDecimal,
                                                         Function<? super JsElem,T> ifOther)

return a matching expression to extract decimal numbers out of json elements.

Type Parameters:

T - the type of the object returned

Parameters:

ifDouble - the function to be applied if this JsElem is a JsDouble

ifBigDecimal - the function to be applied if this JsElem is a JsBigDec

ifOther - the function to be applied if this JsElem is a not a decimal JsNumber

Returns:

a function that takes a JsElem and returns an object of type T

ifIntegralElse

public static <T> Function<JsElem,T> ifIntegralElse(IntFunction<T> ifInt,
                                                          LongFunction<T> ifLong,
                                                          Function<BigInteger,T> ifBigInt,
                                                          Function<? super JsElem,T> ifOther)

return a matching expression to extract integral numbers out of json elements.

Type Parameters:

T - the type of the result

Parameters:

ifInt - function to be applied if the JsElem is a JsInt

ifLong - function to be applied if the JsElem is a JsLong

ifBigInt - function to be applied if the JsElem is a JsBigInt

ifOther - function to be applied if the JsElem is a not an integral number

Returns:

a function that takes a JsElem and returns an object of type T

ifJsonElse

public static <T> Function<JsElem,T> ifJsonElse(Function<? super JsObj,T> ifObj,
                                                      Function<? super JsArray,T> ifArr,
                                                      Function<? super JsElem,T> ifValue)

return a matching expression to extract objs and arrays out of json elements.

Type Parameters:

T - the type of the result

Parameters:

ifObj - function to be applied if the JsElem is a JsObj

ifArr - function to be applied if the JsElem is not a JsArr

ifValue - function to be applied if the JsElem is not a Json

Returns:

a function that takes a JsElem and returns an object of type T

ifJsonElse

public static <T> Function<JsElem,T> ifJsonElse(Function<Json<?>,T> ifJson,
                                                      Function<JsElem,T> ifNotJson)

return a matching expression to extract jsons out of json elements.

Type Parameters:

T - the type of the result

Parameters:

ifJson - function to be applied if the JsElem is a Json

ifNotJson - function to be applied if the JsElem is not a Json

Returns:

a function that takes a JsElem and returns an object of type T

ifNothingElse

public static <T> Function<JsElem,T> ifNothingElse(Supplier<T> nothingSupplier,
                                                         Function<JsElem,T> elseFn)

return a matching expression to extract JsNothing out of json elements.

Type Parameters:

T - the type of the result

Parameters:

nothingSupplier - supplier to be invoked if the JsElem is JsNothing

elseFn - function to be applied if the JsElem is not JsNothing

Returns:

a function that takes a JsElem and returns an object of type T

ifObjElse

public static <T> Function<JsElem,T> ifObjElse(Function<? super JsObj,T> ifObj,
                                                     Function<? super JsElem,T> ifNotObj)

return a matching expression to extract json objects out of json elements.

Type Parameters:

T - the type of the result

Parameters:

ifObj - function to be applied if the JsElem is a JsObj

ifNotObj - function to be applied if the JsElem is not a JsObj

Returns:

a function that takes a JsElem and returns an object of type T

ifPredicateElse

public static <T> Function<JsElem,T> ifPredicateElse(Predicate<JsElem> predicate,
                                                           Function<JsElem,T> ifTrue,
                                                           Function<JsElem,T> ifFalse)

declarative way of implementing an if-else using high order functions

Type Parameters:

T - the type of the result

Parameters:

predicate - the condition that will be tested on the json element

ifTrue - the function to be applied if the predicate is evaluated to true

ifFalse - the function to be applied if the predicate is evaluated to false

Returns:

a function that takes a JsElem and returns an object of type T

ifStrElse

public static <T> Function<JsElem,T> ifStrElse(Function<? super String,T> ifStr,
                                                     Function<? super JsElem,T> ifNotStr)

returns a matching expression to extract strings out of json elements.

Type Parameters:

T - the type of the result

Parameters:

ifStr - the function to be applied if the JsElem is a JsStr

ifNotStr - the function to be applied if the JsElem is not a JsStr

Returns:

a function that takes a JsElem and returns an object of type T