com.pholser.junit.quickcheck.internal.generator

Class ArrayGenerator

java.lang.Object

com.pholser.junit.quickcheck.generator.Generator<Object>

com.pholser.junit.quickcheck.internal.generator.ArrayGenerator

All Implemented Interfaces:

Gen<Object>, Shrink<Object>

public class ArrayGenerator
extends Generator<Object>

Method Summary

Modifier and Type	Method and Description
boolean	canShrink(Object larger) Tells whether this generator is allowed to participate in the Shrink process for the given "larger" value.
void	configure(AnnotatedType annotatedType) Configures this generator using annotations from a given annotated type.
void	configure(Distinct distinct) Tells this generator to produce values which are distinct from each other.
void	configure(Size size) Tells this generator to produce values with a length within a specified minimum and/or maximum, inclusive, chosen with uniform distribution.
List<Object>	doShrink(SourceOfRandomness random, Object larger) Gives some objects that are "smaller" than a given "larger" object.
Object	generate(SourceOfRandomness random, GenerationStatus status) Generates a value, possibly influenced by a source of randomness and metadata about the generation.
BigDecimal	magnitude(Object value) Gives a hint to the shrinking process as to the magnitude of the given value.
void	provide(Generators provided) Supplies the available generators to this one.

Methods inherited from class com.pholser.junit.quickcheck.generator.Generator

addComponentGenerators, canGenerateForParametersOfTypes, canRegisterAsType, compatibleWithTypeParameter, configurationAnnotationsOn, configure, copy, gen, gen, hasComponents, narrow, numberOfNeededComponents, shrink, types

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.pholser.junit.quickcheck.generator.Gen

_gen, filter, filterOptional, flatMap, freq, frequency, map, oneOf, oneOf, pure, times

Method Detail

configure

public void configure(Size size)

Tells this generator to produce values with a length within a specified minimum and/or maximum, inclusive, chosen with uniform distribution.

Parameters:

size - annotation that gives the length constraints

configure

public void configure(Distinct distinct)

Tells this generator to produce values which are distinct from each other.

Parameters:

distinct - Generated values will be distinct if this param is not null.

generate

public Object generate(SourceOfRandomness random,
                       GenerationStatus status)

Description copied from interface: Gen

Generates a value, possibly influenced by a source of randomness and metadata about the generation.

Parameters:

random - source of randomness to be used when generating the value

status - an object that can be used to influence the generated value. For example, generating lists can use the size method to generate lists with a given number of elements.

Returns:

the generated value

canShrink

public boolean canShrink(Object larger)

Description copied from class: Generator

Tells whether this generator is allowed to participate in the Shrink process for the given "larger" value.

Unless overridden, the only criterion for whether a generator is allowed to participate in shrinking a value is if the value can be safely cast to the type of values the generator produces.

Overrides:

canShrink in class Generator<Object>

Parameters:

larger - the "larger" value

Returns:

whether this generator can participate in "shrinking" the larger value

doShrink

public List<Object> doShrink(SourceOfRandomness random,
                             Object larger)

Description copied from class: Generator

Gives some objects that are "smaller" than a given "larger" object.

Unless overridden, a generator will produce an empty list of "smaller" values.

Overrides:

doShrink in class Generator<Object>

Parameters:

random - source of randomness to use in shrinking, if desired

larger - the larger object

Returns:

objects that are "smaller" than the larger object

provide

public void provide(Generators provided)

Description copied from class: Generator

Supplies the available generators to this one.

This is intended for use only by junit-quickcheck itself, and not by creators of custom generators.

Overrides:

provide in class Generator<Object>

Parameters:

provided - repository of available generators

magnitude

public BigDecimal magnitude(Object value)

Description copied from class: Generator

Gives a hint to the shrinking process as to the magnitude of the given value. The shrinking process will prefer trying values of greater magnitude before values of lesser magnitude. If not overridden, this implementation returns "one".

Note to generator writers: Do not worry about normalizing a magnitude to a positive value; the shrinking mechanism will take care of it.

Overrides:

magnitude in class Generator<Object>

Parameters:

value - the value to assess

Returns:

a measure of the given value's magnitude

See Also:

Generator.narrow(Object)

configure

public void configure(AnnotatedType annotatedType)

Description copied from class: Generator

Configures this generator using annotations from a given annotated type.

This method considers only annotations that are themselves marked with GeneratorConfiguration.

By default, the generator will configure itself using this procedure:

• For each of the given annotations:
  • Find a public method on the generator named configure, that accepts a single parameter of the annotation type
  • Invoke the configure method reflectively, passing the annotation as the argument

Overrides:

configure in class Generator<Object>

Parameters:

annotatedType - a type usage