diff options
author | Vincent Ambo <tazjin@google.com> | 2019-07-04T10·18+0100 |
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committer | Vincent Ambo <tazjin@google.com> | 2019-07-04T10·18+0100 |
commit | f723b8b878a3c4a4687b9e337a875500bebb39b1 (patch) | |
tree | e85204cf042c355e90cff61c111e7d8cd15df311 /third_party/bazel/rules_haskell/examples/vector/benchmarks/TestData/ParenTree.hs | |
parent | 2eb1dc26e42ffbdc168f05ef744bd4b4f3e4c36f (diff) |
feat(third_party/bazel): Check in rules_haskell from Tweag r/17
Diffstat (limited to 'third_party/bazel/rules_haskell/examples/vector/benchmarks/TestData/ParenTree.hs')
-rw-r--r-- | third_party/bazel/rules_haskell/examples/vector/benchmarks/TestData/ParenTree.hs | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/third_party/bazel/rules_haskell/examples/vector/benchmarks/TestData/ParenTree.hs b/third_party/bazel/rules_haskell/examples/vector/benchmarks/TestData/ParenTree.hs new file mode 100644 index 000000000000..4aeb750954a9 --- /dev/null +++ b/third_party/bazel/rules_haskell/examples/vector/benchmarks/TestData/ParenTree.hs @@ -0,0 +1,20 @@ +module TestData.ParenTree where + +import qualified Data.Vector.Unboxed as V + +parenTree :: Int -> (V.Vector Int, V.Vector Int) +parenTree n = case go ([],[]) 0 (if even n then n else n+1) of + (ls,rs) -> (V.fromListN (length ls) (reverse ls), + V.fromListN (length rs) (reverse rs)) + where + go (ls,rs) i j = case j-i of + 0 -> (ls,rs) + 2 -> (ls',rs') + d -> let k = ((d-2) `div` 4) * 2 + in + go (go (ls',rs') (i+1) (i+1+k)) (i+1+k) (j-1) + where + ls' = i:ls + rs' = j-1:rs + + |