athanclark / pred-trie

predicative lookup container

pred-trie

A predicative trie library - use predicates instead of literal match to capture classes of results, instead of enumerating distinguished ones.

Usage

The predicates are existentially quantified such that a predicate creates an unknown type, while it's result must have the necessary arity, matching the quantified type, to fulfill the lookup:

PredTrie s a
  = PNil
  | forall t. PCons
      { predicate :: s -> Maybe t
      , result    :: t -> a
      }

...basically.

I broke the lookup phases into "steps", like the tries package, and used the fastest-lookup HashMapStep trie implementation for the literal lookups. For more info, read the code :D

How to run tests

stack test

Benchmarking

stack bench --benchmark-arguments="--output profile.html"

pred-trie's Issues

test/Spec.hs:3:8: Could not find module ‘Data.Trie.Pred.UnifiedSpec’

from the stackage nightly build:

Preprocessing test suite 'spec' for pred-trie-0.2.3...

test/Spec.hs:3:8:
    Could not find module ‘Data.Trie.Pred.UnifiedSpec’
    Perhaps you meant
      Data.Trie.Pred.Unified (needs flag -package-key pred-trie-0.2.3@predt_5RCO4h5Qjqg09vtX6PrPeU)
      Data.Trie.Pred.Unified (needs flag -package-key pred-trie-0.2.3@predt_23KeJIiByNa19Z2Yd27xr9)
      Data.Trie.Pred.Unified.Tail (needs flag -package-key pred-trie-0.2.3@predt_5RCO4h5Qjqg09vtX6PrPeU)
    Use -v to see a list of the files searched for.

The package itself seemed to build okay.

Compilation failure with newest dependencies

[3 of 4] Compiling Data.Trie.Pred.Unified.Tail ( src/Data/Trie/Pred/Unified/Tail.hs, dist/build/Data/Trie/Pred/Unified/Tail.o )

src/Data/Trie/Pred/Unified/Tail.hs:55:23:
    Couldn't match expected type ‘a7 -> b8 -> c7’
                with actual type ‘UPTrie t (r -> x)’
    Relevant bindings include
      xrs :: UPTrie t (r -> x)
        (bound at src/Data/Trie/Pred/Unified/Tail.hs:55:16)
      t :: t (bound at src/Data/Trie/Pred/Unified/Tail.hs:55:14)
      p :: t -> Maybe r
        (bound at src/Data/Trie/Pred/Unified/Tail.hs:55:12)
      suppliment :: (t -> Maybe r)
                    -> t -> UPTrie t (r -> x) -> Maybe (UPTrie t x)
        (bound at src/Data/Trie/Pred/Unified/Tail.hs:55:1)
    In the first argument of ‘(<~$>)’, namely ‘xrs’
    In the first argument of ‘(<$>)’, namely ‘(xrs <~$>)’

src/Data/Trie/Pred/Unified/Tail.hs:96:72:
    Couldn't match type ‘UPTrie t1 (r -> a9 -> c)’ with ‘a9 -> b9 -> c’
    Expected type: [a9 -> b9 -> c]
      Actual type: [UPTrie t1 (r -> a9 -> c)]
    Relevant bindings include
      xrs :: [UPTrie t1 (r -> a9 -> c)]
        (bound at src/Data/Trie/Pred/Unified/Tail.hs:95:25)
      mrx :: Maybe (r -> a9 -> c)
        (bound at src/Data/Trie/Pred/Unified/Tail.hs:95:21)
      p :: t1 -> Maybe r
        (bound at src/Data/Trie/Pred/Unified/Tail.hs:95:19)
      t :: t1 (bound at src/Data/Trie/Pred/Unified/Tail.hs:95:17)
      go :: UPTrie t1 (a9 -> c) -> WrappedMonoid (Maybe (a9 -> c))
        (bound at src/Data/Trie/Pred/Unified/Tail.hs:94:7)
    In the second argument of ‘mapMaybe’, namely ‘xrs’
    In the first argument of ‘mconcat’, namely
      ‘(mapMaybe
          (\ z -> (\ r -> unwrapMonoid $ go $ z <~$> r) <$> p t) xrs)’

pred-trie 0.4.0 build failure

Reproduce this like so:

• stack unpack pred-trie-0.4.0 && cd pred-trie-0.4.0
• stack init --resolver 2015-12-30
• Add the following extra-deps to the generated stack.yaml
  • composition-extra-2.0.0
  • tries-0.0.4
  • rose-trees-0.0.3
  • sets-0.0.5
• stack build

Preprocessing library pred-trie-0.4.0...
[1 of 2] Compiling Data.Trie.Pred.Step ( src/Data/Trie/Pred/Step.hs, dist/build/
Data/Trie/Pred/Step.o )

src/Data/Trie/Pred/Step.hs:49:10: Warning:
    No explicit implementation for
      ‘insert’
    In the instance declaration for ‘Trie NonEmpty s (PredStep c)’

src/Data/Trie/Pred/Step.hs:73:10: Warning:
    No explicit implementation for
      ‘insert’
    In the instance declaration for ‘Trie NonEmpty s (PredSteps c)’

[2 of 2] Compiling Data.Trie.Pred   ( src/Data/Trie/Pred.hs, dist/build/Data/Tri
e/Pred.o )

src/Data/Trie/Pred.hs:110:7:
    Couldn't match expected type ‘HT.HashMapChildren t s t1’
                with actual type ‘(Maybe t2, Maybe (PredTrie s t2))’
    Relevant bindings include
      xs :: HM.HashMap s (HT.HashMapChildren t s t1)
        (bound at src/Data/Trie/Pred.hs:109:27)
      goLit :: HT.HashMapStep t s t1 -> Maybe (NonEmpty s, t2, [s])
        (bound at src/Data/Trie/Pred.hs:109:5)
      goPred :: forall t.
                PredStep PredTrie s t -> Maybe (NonEmpty s, t, [s])
        (bound at src/Data/Trie/Pred.hs:118:5)
      ps :: [PredStep PredTrie s a]
        (bound at src/Data/Trie/Pred.hs:106:41)
      ls :: HT.HashMapStep PredTrie s a
        (bound at src/Data/Trie/Pred.hs:106:27)
      ts :: [s] (bound at src/Data/Trie/Pred.hs:106:13)
      (Some bindings suppressed; use -fmax-relevant-binds=N or -fno-max-relevant
-binds)
    In the pattern: (mx, mxs)
    In a stmt of a 'do' block: (mx, mxs) <- HM.lookup t xs
    In the expression:
      do { (mx, mxs) <- HM.lookup t xs;
           let mFoundHere = ...;
           if null ts then
               mFoundHere
           else
               getFirst
               $ First
                   (do { (pre, y, suff) <- matchPT (NE.fromList ts) =<< mxs;
                         return (t :| NE.toList pre, y, suff) })
                 <> First mFoundHere }

src/Data/Trie/Pred.hs:135:7:
    Couldn't match expected type ‘HT.HashMapChildren t s t1’
                with actual type ‘(Maybe t2, Maybe (PredTrie s t2))’
    Relevant bindings include
      xs :: HM.HashMap s (HT.HashMapChildren t s t1)
        (bound at src/Data/Trie/Pred.hs:134:27)
      goLit :: HT.HashMapStep t s t1 -> Maybe [(NonEmpty s, t2, [s])]
        (bound at src/Data/Trie/Pred.hs:134:5)
      goPred :: forall t.
                PredStep PredTrie s t -> Maybe [(NonEmpty s, t, [s])]
        (bound at src/Data/Trie/Pred.hs:144:5)
      ps :: [PredStep PredTrie s a]
        (bound at src/Data/Trie/Pred.hs:131:43)
      ls :: HT.HashMapStep PredTrie s a
        (bound at src/Data/Trie/Pred.hs:131:29)
      ts :: [s] (bound at src/Data/Trie/Pred.hs:131:15)
      (Some bindings suppressed; use -fmax-relevant-binds=N or -fno-max-relevant-binds)
    In the pattern: (mx, mxs)
    In a stmt of a 'do' block: (mx, mxs) <- HM.lookup t xs
    In the expression:
      do { (mx, mxs) <- HM.lookup t xs;
           let mFoundHere = ...
               prependAncestry (pre, x, suff) = ...;
           if null ts then
               mFoundHere
           else
               do { foundHere <- mFoundHere;
                    .... } }