Clojure Programming/Examples/API Examples/Structure Tools

accessor user=> (defstruct employee :name :id) #'user/employee user=> (def e (struct employee "John" 123)) #'user/e user=> e {:name "John", :id 123} user=> ("name" e) ; FAIL: string not an accessor java.lang.ClassCastException: java.lang.String cannot be cast to clojure.lang.IFn (NO_SOURCE_FILE:0) user=> (:name e) "John" user=> (def employee-name (accessor employee :name)) ; bind accessor to e-name #'user/employee-name user=> (employee-name e) ; use accessor "John" assoc See struct-map for more. defstruct See struct-map for more. struct See struct-map for more. struct-map user=> (defstruct employee :name :id) #'user/employee user=> (struct employee "Mr. X" 10) {:name "Mr. X", :id 10} user=> (struct-map employee :id 20 :name "Mr. Y") {:name "Mr. Y", :id 20} user=> (def a (struct-map employee :id 20 :name "Mr. Y")) #'user/a user=> (def b (struct employee "Mr. X" 10)) #'user/b user=> (:name a) ; observe that :name is an accessor "Mr. Y" user=> (:id b) ; same with :id 10 user=> (b :id) 10 user=> (b :name) "Mr. X" user=> (assoc a :name "New Name") {:name "New Name", :id 20} user=> a ; note that 'a' is immutable and did not change {:name "Mr. Y", :id 20} user=> (def a1 (assoc a :name "Another New Name")) ; bind to a1 #'user/a1 user=> a1 {:name "Another New Name", :id 20}