Generators

[Joe Bowbeer]

To be clear: range and ints() are the only remaining int generators?

There should be an iterator for stepping functions and infinite streams of
1's etc.

ints() is nice anyway for samples and demos.  I can't complain too much.
 Though the iterator form is pretty simple.  I think ints() should wrap,
just like the simple iterator implementation.

Will the T generators allow us to generate streams of BigInteger?  Those
are useful for samples and demos.  Generate a gazillion Fibonacci numbers.


On Thu, Jan 3, 2013 at 12:50 PM, Brian Goetz <brian.goetz at oracle.com> wrote:

> Things like
>
> int sumOfFirstHundredPrimes =
>   ints().filter(isPrime()).**limit(100).sum();
>
> where you don't know how many input elements you'll have to examine.
>
>
>
> On 1/3/2013 3:44 PM, Sam Pullara wrote:
>
>> These look pretty reasonable to me. What is the motivation for ints()?
>>
>> Sam
>>
>> On Thu, Jan 3, 2013 at 11:49 AM, Brian Goetz <brian.goetz at oracle.com
>> <mailto:brian.goetz at oracle.com**>> wrote:
>>
>>     I'm looking over our generators.  Currently we have:
>>
>>        repeat(T)
>>        repeat(n, T)
>>        repeatedly(Supplier<T>)
>>        repeatedly(n, Supplier<T>)
>>        iterate(T, UnaryOperator<T>)
>>        cycle(Iterable)
>>
>>     I'd like to pare this down a lot.  Paul and I have been discussing
>>     techniques for making limit() more efficient, at which point the
>>     first four can collapse to
>>
>>        generate(Supplier<T>)
>>
>>     since you can simulate repeat(T) with generate(() -> T) and the
>>     limited versions with generate().limit().
>>
>>     That leaves us with
>>
>>        iterate(T, UnaryOperator<T>)
>>        cycle(Iterable)
>>
>>     and I'm thinking cycle doesn't pull its weight either.  If we took
>>     that out, we'd be down to the pleasantly small set of:
>>
>>        generate(Supplier<T>)
>>        iterate(T, UnaryOperator<T>)
>>
>>     For integer generators, we have
>>
>>        range(from, to)
>>
>>     and I think we should add
>>
>>        ints() -> sugar for range(0, MAX_INT)
>>
>>     (Or should ints() be truly infinite, wrapping around?)
>>
>>
>>
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