CODEWITHSUNDEEP
eiffel
geforce
geforce

Reputation: 61

Finding a object in a HASH_TABLE using item feature on EIFFEL

I am having a problem comparing two objects in a HASH_TABLE

PERSON is a class with attributes such as name, b-day, status of relationship, spouse name, spouse id. So basically composed of attributes code:

list: HASH_TABLE[PERSON, INTEGER_64]

put(id1, id2: INTEGER_64)
local
   p1, p2: PERSON
do
   p1 := model.list.at(id)
      -- or 
   p1 := model.list.search(id)
   p1 := model.list.found_item -- same error as below
end

error: Source of assignment is not compatible with target.

THE FEATURES USED RETURN "DETACHABLE G"

I think I should be doing "if attached" to ensure item feature returns the correct object type and then assign? I'm not exactly sure how to cast the object though.

The error is triggered by calling above feature

The reason i need these functions to work is that I can sort easier

Upvotes: 0

Views: 122

Answers (1)

Alexander Kogtenkov
Alexander Kogtenkov

Reputation: 5810

The features return detachable G because it is possible that no element is found. Therefore you need to use object tests, e.g.

if
   attached model.list [id1] as p1 and then
   attached model.list [id2] as p2
then
   ... -- use p1 and p2
end

Upvotes: 2

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