Keywords are symbolic constants which evaluate to themselves. A keyword is a symbol whose first (or last) character is a colon (":").
| keyword obj | STKLOS Procedure |
Returns #t if obj is a keyword, otherwise returns #f.
(keyword? 'foo) => #f
(keyword? ':foo) => #t
(keyword? 'foo:) => #t
(keyword? :foo) => #t
(keyword? foo:) => #t
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| make-keyword s | STKLOS Procedure |
Builds a keyword from the given s. The parameter s must be a symbol
or a string.
(make-keyword "test") => :test
(make-keyword 'test) => :test
(make-keyword ":hello") => ::hello
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| keyword->string key | STKLOS Procedure |
Returns the name of key as a string. The result does not contain a colon.
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| key-get list key | STKLOS Procedure |
| key-get list key default | STKLOS Procedure |
List must be a list of keywords and their respective values.
key-get scans the list and returns the value
associated with the given key. If key does
not appear in an odd position in list, the specified
default is returned, or an error is raised if no default was
specified.
(key-get '(:one 1 :two 2) :one) => 1
(key-get '(:one 1 :two 2) :four #f) => #f
(key-get '(:one 1 :two 2) :four) => error
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| key-set! list key value | STKLOS Procedure |
List must be a list of keywords and their respective values.
key-set! sets the value associated to key in the keyword list.
If the key is already present in list, the keyword list is
physically changed.
(let ((l '(:one 1 :two 2)))
(set! l (key-set! l :three 3))
(cons (key-get l :one)
(key-get l :three)) => (1 . 3)
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| key-delete! list key | STKLOS Procedure |
List must be a list of keywords and their respective values.
key-delete remove the key and its associated value of the keyword
list. The key can be absent of the list.
(key-delete '(:one 1 :two 2) :one) => (:one 1)
(key-delete '(:one 1 :two 2) :three) => (:one 1 :two 2)
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