fae58e140d
The old 'HashTable' type is now the union of the other 3 hash types. - all operations that used to work on 'HashTable's still work, but some now have more specific outputs - `#hash` literals have type `ImmutableHash` - `immutable?` and `hash-weak?` are filters - `Mutable-` and `Weak-` hashes have corresponding `Top` types, `HashTableTop` is now a union - the contact for `(U (Immutable-Hash K1 V1) (Mutable-Hash K2 V2))` is ONE `hash/c` Minor notes: - renamed internal identifiers containing 'Hashtable' to all use 'HashTable' - add Racket guide/reference 'secref' functions
36 lines
969 B
Racket
36 lines
969 B
Racket
#lang typed/racket/base
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;; Test filters for hash types
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(: filter-HT (-> (HashTable Integer Integer) HashTableTop))
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(define (filter-HT h)
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(cond
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[(immutable? h)
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(ann h (Immutable-HashTable Integer Integer))]
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[(hash-weak? h)
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(ann h (Weak-HashTable Integer Integer))]
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[else
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(ann h (Mutable-HashTable Integer Integer))]))
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(: filter-U (-> (U #f (HashTable Integer Integer)) Any))
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(define (filter-U maybe-ht)
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(cond
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[(immutable? maybe-ht)
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(ann maybe-ht (Immutable-HashTable Integer Integer))]
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[(and maybe-ht (hash-weak? maybe-ht))
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(ann maybe-ht Weak-HashTableTop)]
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[(hash? maybe-ht)
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(ann maybe-ht Mutable-HashTableTop)]
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[else
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(ann maybe-ht #f)]))
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(void
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(filter-HT (make-immutable-hash '((1 . 1))))
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(filter-HT (make-hash '((1 . 1))))
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(filter-HT (make-weak-hash '((1 . 1))))
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(filter-U #f)
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(filter-U (make-immutable-hash '((1 . 1))))
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(filter-U (make-hash '((1 . 1))))
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(filter-U (make-weak-hash '((1 . 1)))))
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