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schemelisp

Is quote in Lisp/Scheme same as a string?

There are already many questions regarding quote in Lisp, and I understand that it doesn't evaluate the expression. But I haven't seen its comparison to a string.

Is the quote same as a string? If not, how are they different?

Solution

  • In Lisp:

    * (type-of "a b c")
(SIMPLE-ARRAY CHARACTER (5))
* (type-of '(a b c))
CONS
* (type-of "(a b c)")
(SIMPLE-ARRAY CHARACTER (7))

    A string is always an object of some string type. A string always evaluates to itself.

    The quote operator returns the quoted object - whatever that object may be: a string, a number, a symbol, a list made of cons cells, ...

    CL-USER 2 > '"a b c"
"a b c"

CL-USER 3 > '3
3

CL-USER 4 > 'abc
ABC

CL-USER 5 > '(a b c)
(A B C)