Foundation instead of in the original English.
\1f
+File: lispref.info, Node: Self-Evaluating Forms, Next: Symbol Forms, Up: Forms
+
+Self-Evaluating Forms
+---------------------
+
+ A "self-evaluating form" is any form that is not a list or symbol.
+Self-evaluating forms evaluate to themselves: the result of evaluation
+is the same object that was evaluated. Thus, the number 25 evaluates to
+25, and the string `"foo"' evaluates to the string `"foo"'. Likewise,
+evaluation of a vector does not cause evaluation of the elements of the
+vector--it returns the same vector with its contents unchanged.
+
+ '123 ; An object, shown without evaluation.
+ => 123
+ 123 ; Evaluated as usual--result is the same.
+ => 123
+ (eval '123) ; Evaluated "by hand"--result is the same.
+ => 123
+ (eval (eval '123)) ; Evaluating twice changes nothing.
+ => 123
+
+ It is common to write numbers, characters, strings, and even vectors
+in Lisp code, taking advantage of the fact that they self-evaluate.
+However, it is quite unusual to do this for types that lack a read
+syntax, because there's no way to write them textually. It is possible
+to construct Lisp expressions containing these types by means of a Lisp
+program. Here is an example:
+
+ ;; Build an expression containing a buffer object.
+ (setq buffer (list 'print (current-buffer)))
+ => (print #<buffer eval.texi>)
+ ;; Evaluate it.
+ (eval buffer)
+ -| #<buffer eval.texi>
+ => #<buffer eval.texi>
+
+\1f
File: lispref.info, Node: Symbol Forms, Next: Classifying Lists, Prev: Self-Evaluating Forms, Up: Forms
Symbol Forms