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Is list empty Lisp?
In NewLisp, lists are containers: objects of list type which contain a linked list of the items, so empty lists are empty containers.
Is Common Lisp typed?
Common Lisp provides a variety of types of data objects. It is important to note that in Lisp it is data objects that are typed, not variables. Any variable can have any Lisp object as its value.
What is true in Lisp?
In Lisp the convention is that nil, or the empty list, means false, and anything else means true.
Is Common Lisp type safe?
In general, Common Lisp is a type-safe language. A Common Lisp compiler is responsible for inserting dynamic checks for operations whose type safety cannot be proven statically.
What is false Lisp?
Lisp includes a number of functions that give a true or false answer – they are called predicates, and often (but not always) have names ending with p. In Lisp the convention is that nil, or the empty list, means false, and anything else means true. If you want to represent true you use the special Lisp operator, t.
What makes a list an empty list in Lisp?
In Lisp languages that aren’t spectacular cluster-fumbles of this sort, empty lists are atoms, and non-empty lists are binary cells with a field which holds the first item, and another field that holds the rest of the list. Lists can share suffixes.
Where to learn how to practically use Common Lisp?
More advanced Common Lisp: Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp. The book is interesting also for non-AI programmers. Lots of practical advice: Common Lisp Recipes.
What makes an empty list empty in newLISP?
In NewLisp, lists are containers: objects of list type which contain a linked list of the items, so empty lists are empty containers. [Reference].
How to return multiple values in Common Lisp?
This question has been already answered on SO: values function in Common Lisp. Briefly, multiple values is a facility to return many objects without allocating extra memory. E.g. floor must return two values – quotient and remainder. It can return a list (or a pair) or it can return two values .