Groovy range with a 0.5 step size

What's the most elgant way in Groovy to specify a range of integers and the 0.5 steps between them? e.g.: 1, 1.5, 2, 2.5, 3, 3.5, 4

Edit: To clarify: As an end result I need a range object for use in a Grails constraint. Though I suppose a list would be OK too.

Best way I can see is using the step command.

i.e.


    1.step(4, 0.5){ print "$it "}

would print out: "1 1.5 2.0 2.5 3.0 3.5"

A little late, but this works too

A one-liner for your above set:

(2..8)*.div(2)

Soo, to build on above. To test if a value val is in the range 1..n but with half values:

def range = 2..(n*2).collect { return it/2.0 }
return range.contains( val )

Something like that would work, but isn't as pretty as I'd like, but it lets you build the range once and use it multiple times, if you need that.

FYI, as of Groovy 1.6.0, it seems not to support natively. There exists only ObjectRange.step(int) at the moment.

http://groovy.codehaus.org/api/groovy/lang/ObjectRange.html#step%28int%29

Cheat.

Map your desired range into another that is more easily handled by Groovy. You want something like:

 y in [x, x+0.5, x+1, x+1.5, ..., x+n] // tricky if you want a range object

which is true if and only if:

 2*y in [2x,2x+1,2x+2,2x+3,...,2x+2n] // over whole integers only

which is the same as the range object:

(2*x)..(2*x+2*n).contains(2*y)   //simple!

or:

switch (2*y) {
   case (2*x)..(2*x+2*n): doSomething(); break;
   ...}

def r = []
(0..12).each() {
  r << it
  r << it + 0.5
}

my answer is the following:

(1..4).step(0.5)

(1..7).collect{0.5*it} is the best I can think of

来源：https://stackoverflow.com/questions/573155/groovy-range-with-a-0-5-step-size

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