Clojure

Reduce broken on some primitive vectors

Details

  • Type: Defect Defect
  • Status: Open Open
  • Priority: Major Major
  • Resolution: Unresolved
  • Affects Version/s: Release 1.3, Release 1.4, Release 1.5, Release 1.6
  • Fix Version/s: Release 1.7
  • Component/s: None
  • Labels:
  • Patch:
    Code and Test
  • Approval:
    Screened

Description

In some cases, reduce over a sequence from a primitive vector created with vector-of will return incorrect answers:

user=> (into [] (drop 32 (into [] (range 33))))
[32]
user=> (into [] (drop 32 (into (vector-of :int) (range 33))))
[0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32]

Second call should return [32] just like the first one.

Cause: VecSeq (seq on primitive Vec obtained with vector-of) maintains two flags: i is the total number of elements prior to the current node in this seq. offset is the offset in the current anode. When using internal-reduce on a VecSeq, the starting index for the reduce was using offset and ignoring i.

Solution: Use (+ i offset) as the starting index.

Patch: clj-1362-v1.patch

Screened by:

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Dates

  • Created:
    Updated: