CODEWITHSUNDEEP
clips
Nicola Ben
Nicola Ben

Reputation: 11367

CLIPS: retrieve slot value from multislot if INSTANCES

I have an object with a multislot of INSTANCE. I have problems in getting instance's slot with one call. Example:

(defclass AUTOMA (is-a USER)
(slot uuid))

(defclass TUTOMA (is-a USER)
(multislot list 
(type INSTANCE)))


(make-instance A1 of AUTOMA
(uuid a1))
(make-instance A2 of AUTOMA
(uuid a2))
(make-instance T1 of TUTOMA
(list [a1] [a2]))

I want to retrive the first object uuid of the multislot list.

1) Try with "first$":

CLIPS> (first$ (send [T1] get-list))
([a1])
CLIPS> (send (first$ (send [T1] get-list)) get-uuid)
[MSGFUN1] No applicable primary message-handlers found for get-uuid.
FALSE

2) Try with "implode$":

CLIPS> (implode$ (first$ (send [T1] get-list)))
"[a1]"
CLIPS> (send (implode$ (first$ (send [T1] get-list))) get-uuid)
[MSGFUN1] No applicable primary message-handlers found for get-uuid.
FALSE

It seems that both ([a1]) and "[a1]" are not good for the (send XXX get-uuid) command. Any suggestions, please?

Thank you Nic

Upvotes: 0

Views: 883

Answers (1)

Gary Riley
Gary Riley

Reputation: 10757

First$ returns a multifield value and implode$ returns a string. You need to use an instance name. Use nth$ to retrieve a field from within a multifield. You also need to keep the case used for your instance names consistent:

CLIPS> 
(defclass AUTOMA 
   (is-a USER)
   (slot uuid))
CLIPS> 
(defclass TUTOMA 
   (is-a USER)
   (multislot list (type INSTANCE)))
CLIPS> (make-instance A1 of AUTOMA (uuid a1))
[A1]
CLIPS> (make-instance A2 of AUTOMA (uuid a2))
[A2]
CLIPS> (make-instance T1 of TUTOMA (list [A1] [A2]))
[T1]
CLIPS> (send (nth$ 1 (send [T1] get-list)) get-uuid)
a1
CLIPS>

Upvotes: 1

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