steel/hash
hash
Creates an immutable hash table with each given key mapped to the following val.
Each key must have a val, so the total number of arguments must be even.
(hash key val ...) -> hash?
key : hashable? val : any/c
Note: the keys must be hashable.
Examples
> (hash 'a 10 'b 20)",
r#"=> #<hashmap {
'a: 10,
'b: 20,
}>"#,
hash-clear
Clears the entries out of the existing hashmap. Will attempt to reuse the existing memory if there are no other references to the hashmap.
(hash-clear h) -> hash?
h: hash?
Examples
> (hash-clear (hash 'a 10 'b 20))
=> '#hash()
hash-contains?
Checks whether the given map contains the given key. Key must be hashable.
(hash-contains? map key) -> bool?
- map : hash?
- key : hashable?
Example
> (hash-contains? (hash 'a 10 'b 20) 'a) ;; => #true
> (hash-contains? (hash 'a 10 'b 20) 'not-there) ;; => #false
hash-empty?
Checks whether the hash map is empty
(hash-empty? m) -> bool?
m: hash?
Examples
> (hash-empty? (hash 'a 10)) ;; => #f
> (hash-emptY? (hash)) ;; => #true
hash-insert
Returns a new hashmap with the additional key value pair added. Performs a functional update, so the old hash map is still accessible.
(hash-insert map key val) -> hash?
- map : hash?
- key : any/c
- val : any/c
Examples
> (hash-insert (hash 'a 10 'b 20) 'c 30)
=> #<hashmap {
'a: 10,
'b: 20,
'c: 30
}>
hash-keys->list
Returns the keys of the given hash map as a list.
(hash-keys->list map) -> (listof hashable?)
- map : hash?
Examples
> (hash-keys->list? (hash 'a 'b 20)) ;; => '(a b)
hash-keys->vector
Returns the keys of the given hash map as an immutable vector
(hash-keys->vector map) -> (vectorof any/c)?
map: hash?
Examples
> (hash-keys->vector (hash 'a 10 'b 20)),
=> ['a 'b]",
hash-length
Returns the number of key value pairs in the map
(hash-length map) -> (and positive? int?)
- map : hash?
Examples
> (hash-length (hash 'a 10 'b 20)) ;; => 2
hash-ref
Gets the key from the given map. Raises an error if the key does not exist. hash-get is an alias for this.
(hash-ref map key) -> any/c
- map : hash?
- key : any/c
Examples
> (hash-ref (hash 'a 10 'b 20) 'b) ;; => 20
hash-try-get
Gets the key from the given map. Returns #false if the key does not exist.
(hash-try-get map key) -> (or any/c #false)
- map : hash?
- key : any/c
Examples
> (hash-try-get (hash 'a 10 'b 20) 'b) ;; => 20
> (hash-try-get (hash 'a 10 'b 20) 'does-not-exist) ;; => #false
hash-union
Constructs the union of two hashmaps, keeping the values in the left map when the keys exist in both maps.
Will reuse memory where possible.
(hash-union l r) -> hash?
Examples
> (hash-union (hash 'a 10) (hash 'b 20)) ;; => '#hash((a . 10) (b . 20))
hash-values->list
Returns the values of the given hash map as a list
(hash-values->list? map) -> (listof any/c)?
map: hash?
Examples
> (hash-values->list? (hash 'a 10 'b 20)),
=> '(10 20)",
hash-values->vector
Returns the values of the given hash map as an immutable vector
(hash-values->vector map) -> (vectorof any/c)?
map: hash?
Examples
> (hash-keys->vector (hash 'a 10 'b 20)),
=> [10 10]",