Alan 3 Beta 05: Testing Nested Locations as Verb Parameters

nested_location.alan

--==============================================================================
-- "Test Verb on Enclosing Location" by Tristano Ajmone
--==============================================================================
-- Alan 3.0 Beta5

THE world IsA LOCATION.
  -- Outer location enclosing other locations...
  VERB touch
    DOES "You touch $+1."
  END VERB.
END THE.

-- 'touch' works with 'tent' and 'ball'! ('world' and 'yard' out of scope)
SYNTAX touch = touch (obj)
  WHERE obj IsA ENTITY
    ELSE "Invalid parameter for examine!"

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-- 'search' works with 'tent' and 'ball'! ('world' and 'yard' out of scope)
SYNTAX search = search (obj)
  WHERE obj IsA ENTITY --> 'ENTITY' includes locations that are nested AT the
                       --   current location of hero.
    ELSE "Invalid parameter for examine!"

-- 'inspect' works with 'ball' but fail with 'tent' (defaults to OBJECT)!
-- ('world' and 'yard' out of scope)
SYNTAX inspect = inspect (obj).

THE yard IsA LOCATION AT world.
  DESCRIPTION "You can see a tent here."

  VERB search
    DOES "You search $+1."
  END VERB.

  VERB inspect
    DOES "You inspect $+1."
  END VERB.
END THE yard.

THE tent IsA LOCATION AT yard.
END THE.

THE ball IsA OBJECT AT yard.
END THE.
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-- 'examine' works with 'ball' but fail with 'tent' (because added to THING)!
SYNTAX examine = examine (obj)
  WHERE obj IsA ENTITY
    ELSE "Invalid parameter for examine!"

    SYNONYMS x = examine.

ADD TO EVERY THING
  VERB examine
    DOES "You examine $+1."
  END VERB.
END ADD TO.
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Start at yard.