Details
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Type:
Wish
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Status:
Closed
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Priority:
Trivial
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Resolution: Fixed
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Affects Version/s: 1.0-JSR-1
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Fix Version/s: 1.1-beta-2
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Component/s: None
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Labels:None
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Environment:Groovy Version: 1.0-jsr-01 JVM: Blackdown-1.4.2-01
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Number of attachments :
Description
In my opinion it would be nice to allow for lvalue slicing using the range operator. Example: reverse the first n elements of a list
// throws IllegalArgumentException
list[0..<n] = list[0..<n].reverse()
The exception is thrown in DefaultGroovyMethods.java ("You must specify a list of 2 indexes to create a sub-list") for all n != 2 (i.e. almost always)
Rewriting the statement as
list[0, n-1] = list[0..<n].reverse()
works but is not as nice.
It might be enough to change DefaultGroovyMethods.java from
if (splice.size() != 2) {
throw new IllegalArgumentException("You must specify a list of 2 indexes to create a sub-list");
}
int left = InvokerHelper.asInt(splice.get(0));
int right = InvokerHelper.asInt(splice.get(1));
to
int left = InvokerHelper.asInt(splice.get(0));
int right = InvokerHelper.asInt(splice.get(splice.length()));
but i'm not sure what other parts are affected 'cause i'm a complete newbie
Thanks
Jochen
In HEAD, this now behaves as follows:
def list = [0, 1, 2, 3, 4, 5] list[1..<4] = list[1..<4].reverse() println list // => [0, 3, 2, 1, 4, 5]Which I believe is the requested behaviour.
def list = [0, 1, 2, 3, 4, 5] list[1..<4] = list[1..<4].reverse() println list // => [0, 3, 2, 1, 4, 5]