The (srfi 69) library defines basic hash tables.
Hash tables are widely recognised as a fundamental data structure for a wide variety of applications. A hash table is a data structure that:
- provides a mapping from some set of keys to some set of values associated to those keys
- has no intrinsic order for the (key, value) associations it contains
- supports in-place modification as the primary means of setting the contents of a hash table
- provides key lookup and destructive update in amortised constant time, provided that a good hash function is used
See the SRFI document for more information.
Hash table size must be strictly less than 536,870,909.
The default implementation of record hashing is severely suboptimal - if you want to store records in a hash table, use a custom hashing function.
This implementation does not distinguish hash and hash-by-identity.
Additionally, symbol hashing is done by string-hashing the result of
symbol->string on the symbol, making symbols identical to strings for the
purpose of hash table key performance.
make-hash-table
hash-table?
alist->hash-table
hash-table-equivalence-function
hash-table-hash-function
hash-table-ref
hash-table-ref/default
hash-table-set!
hash-table-delete!
hash-table-exists?
hash-table-update!
hash-table-update!/default
hash-table-size
hash-table-keys
hash-table-values
hash-table-walk
hash-table-fold
hash-table->alist
hash-table-copy
hash-table-merge!
hash
string-hash
string-ci-hash
hash-by-identity
(make-hash-table)
(make-hash-table equal?)
(make-hash-table equal? hash)
(make-hash-table equal? hash size)
Create a new hash table.
(hash-table? obj)
Determine if the given object is a hash table.
(alist->hash-table alist)
(alist->hash-table alist equal?)
(alist->hash-table alist equal? hash)
Convert given association list to a hash table.
(hash-table-equivalence-function hash-table)
Returns the equivalence predicate used for keys of hash-table.
(hash-table-hash-function hash-table)
Returns the hash function used for keys of hash-table.
(hash-table-ref hash-table key)
(hash-table-ref hash-table key thunk)
This procedure returns the value associated to key in hash-table. If no value is associated to key and thunk is given, it is called with no arguments and its value is returned.
(hash-table-ref/default hash-table key default)
Return the value associated to key in the hash table, or default if the key is not found.
(hash-table-set! hash-table key value)
Sets the value associated to key in the given hash table.
(hash-table-delete! hash-table key)
Removes any value association for key in the given hash table.
(hash-table-exists? hash-table key)
Determines if the given key exists in the hash table.
(hash-table-update! hash-table key function)
(hash-table-update! hash-table key function thunk)
(hash-table-update!/default hash-table key function default)
(hash-table-size hash-table)
Return the number of associations in the hash table.
(hash-table-keys hash-table)
Return a list of keys in the hash table.
(hash-table-values hash-table)
Return a list of values in the hash table.
(hash-table-walk hash-table proc)
proc should be a function taking two arguments, a key and a value. This procedure calls proc for each association in hash-table, giving the key of the association as key and the value of the association as value. The results of proc are discarded.
(hash-table-fold hash-table f init-value)
This procedure calls f for every association in hash-table with three arguments: the key of the association key, the value of the association value, and an accumulated value, val. val is init-value for the first invocation of f, and for subsequent invocations of f, the return value of the previous invocation of f. The value final-value returned by hash-table-fold is the return value of the last invocation of f.
(hash-table->alist hash-table)
Return an association list using the keys and values from the hash table.
(hash-table-copy hash-table)
Return a new hash table with the same data as the original.
(hash-table-merge! hash-table1 hash-table2)
Adds all mappings in hash-table2 into hash-table1 and returns the resulting hash table.
(hash object)
(hash object bound)
Return a hash value for object in the range 0 to bound.
(string-hash string)
(string-hash string bound)
Same as hash except the argument must be a string.
(string-ci-hash string)
(string-ci-hash string bound)
Case insensitive version of string-hash.
(hash-by-identity object)
(hash-by-identity object bound)
The same as hash, except that this function is only guaranteed to be acceptable for eq?.