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Clarify lexical binding with symbol args behavior

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* doc/lispref/variables.texi (Lexical Binding): Clarify that symbol
arguments always refer to dynamic values (Bug #23781).  Remove mention
of obsolete restriction regarding lexical binding for defun and
defmacro, this no longer applies since 61b108cc 2012-05-29 "*
lisp/emacs-lisp/byte-run.el (defmacro, defun): Move from C...".
This commit is contained in:
Noam Postavsky 2016-06-24 20:39:24 -04:00
parent f981b31367
commit 850ba444a7
1 changed files with 8 additions and 6 deletions
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14
doc/lispref/variables.texi
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@ -974,7 +974,7 @@ itself.
@cindex lexical environment
Here is how lexical binding works. Each binding construct defines a
@dfn{lexical environment}, specifying the symbols that are bound
@dfn{lexical environment}, specifying the variables that are bound
within the construct and their local values. When the Lisp evaluator
wants the current value of a variable, it looks first in the lexical
environment; if the variable is not specified in there, it looks in
@ -1032,11 +1032,13 @@ lives on even after the @code{let} binding construct has exited. Each
time we evaluate the closure, it increments @code{x}, using the
binding of @code{x} in that lexical environment.
Note that functions like @code{symbol-value}, @code{boundp}, and
@code{set} only retrieve or modify a variable's dynamic binding
(i.e., the contents of its symbol's value cell). Also, the code in
the body of a @code{defun} or @code{defmacro} cannot refer to
surrounding lexical variables.
Note that unlike dynamic variables which are tied to the symbol
object itself, the relationship between lexical variables and symbols
is only present in the interpreter (or compiler). Therefore,
functions which take a symbol argument (like @code{symbol-value},
@code{boundp}, and @code{set}) can only retrieve or modify a
variable's dynamic binding (i.e., the contents of its symbol's value
cell).
@node Using Lexical Binding
@subsection Using Lexical Binding