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Note that lex bound lambda forms are not self-quoting (Bug#33199)

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* doc/lispref/functions.texi (Anonymous Functions):
* lisp/subr.el (lambda): Note that under lexical binding a lambda form
yields a closure object (Bug#33199).
This commit is contained in:
Noam Postavsky 2018-10-29 19:01:07 -04:00
parent fa605f242e
commit 39e85a0c6c
2 changed files with 13 additions and 9 deletions
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9
doc/lispref/functions.texi
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@ -1082,15 +1082,18 @@ This macro returns an anonymous function with argument list
@var{args}, documentation string @var{doc} (if any), interactive spec @var{args}, documentation string @var{doc} (if any), interactive spec
@var{interactive} (if any), and body forms given by @var{body}. @var{interactive} (if any), and body forms given by @var{body}.
In effect, this macro makes @code{lambda} forms self-quoting: Under dynamic binding, this macro effectively makes @code{lambda}
evaluating a form whose @sc{car} is @code{lambda} yields the form forms self-quoting: evaluating a form whose @sc{car} is @code{lambda}
itself: yields the form itself:
@example @example
(lambda (x) (* x x)) (lambda (x) (* x x))
@result{} (lambda (x) (* x x)) @result{} (lambda (x) (* x x))
@end example @end example
Note that when evaluting under lexical binding the result is a closure
object (@pxref{Closures}).
The @code{lambda} form has one other effect: it tells the Emacs The @code{lambda} form has one other effect: it tells the Emacs
evaluator and byte-compiler that its argument is a function, by using evaluator and byte-compiler that its argument is a function, by using
@code{function} as a subroutine (see below). @code{function} as a subroutine (see below).

13
lisp/subr.el
View file

@ -93,12 +93,13 @@ Info node `(elisp)Specification List' for details."
`(put (quote ,symbol) 'edebug-form-spec (quote ,spec))) `(put (quote ,symbol) 'edebug-form-spec (quote ,spec)))
(defmacro lambda (&rest cdr) (defmacro lambda (&rest cdr)
"Return a lambda expression. "Return an anonymous function.
A call of the form (lambda ARGS DOCSTRING INTERACTIVE BODY) is Under dynamic binding, a call of the form (lambda ARGS DOCSTRING
self-quoting; the result of evaluating the lambda expression is the INTERACTIVE BODY) is self-quoting; the result of evaluating the
expression itself. The lambda expression may then be treated as a lambda expression is the expression itself. Under lexical
function, i.e., stored as the function value of a symbol, passed to binding, the result is a closure. Regardless, the result is a
`funcall' or `mapcar', etc. function, i.e., it may be stored as the function value of a
symbol, passed to `funcall' or `mapcar', etc.
ARGS should take the same form as an argument list for a `defun'. ARGS should take the same form as an argument list for a `defun'.
DOCSTRING is an optional documentation string. DOCSTRING is an optional documentation string.