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definition:
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delete' :: String -> InternalTrie a -> Maybe (InternalTrie a)
delete' k (InternalTrie v ts) = do
res <- case k of
[] -> v *> Just (InternalTrie Nothing ts)
(c:cs) -> do
t <- Prelude.lookup c ts
t' <- delete' cs t
let e = (c, t')
es = filter ((/= c) . fst) ts
return $ InternalTrie v (if null' t then es else e : es)
return $ sanitize res
where
sanitize :: InternalTrie a -> InternalTrie a
sanitize (InternalTrie v' ts') =
InternalTrie v' (filter (not . null' . snd) ts')
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demand:
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arguments 1 2
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deterministic:
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deterministic operation
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documentation:
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-- Tries to delete a key from the internal trie. If the key is not in the trie,
-- `Nothing` is returned. This feedback is used to determine whether the size of the trie
-- has changed.
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failfree:
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(_, _)
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indeterministic:
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referentially transparent operation
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infix:
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no fixity defined
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iotype:
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{(_,{InternalTrie}) |-> _}
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name:
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delete'
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precedence:
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no precedence defined
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result-values:
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_
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signature:
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String -> InternalTrie a -> Prelude.Maybe (InternalTrie a)
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solution-complete:
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operation might suspend on free variables
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terminating:
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possibly non-terminating
|
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totally-defined:
|
possibly non-reducible on same data term
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