@table @asis
@item Print name
@cindex print name cell
-The @dfn{print name cell} holds a string which names the symbol for
+The @dfn{print name cell} holds a string that names the symbol for
reading and printing. See @code{symbol-name} in @ref{Creating Symbols}.
@item Value
The function cell or the value cell may be @dfn{void}, which means
that the cell does not reference any object. (This is not the same
thing as holding the symbol @code{void}, nor the same as holding the
-symbol @code{nil}.) Examining a cell which is void results in an error,
+symbol @code{nil}.) Examining a cell that is void results in an error,
such as @samp{Symbol's value as variable is void}.
The four functions @code{symbol-name}, @code{symbol-value},
through all the symbols in the bucket for that name's hash code.
@cindex interning
- If a symbol with the desired name is found, then it is used. If no
-such symbol is found, then a new symbol is created and added to the
-obarray bucket. Adding a symbol to an obarray is called @dfn{interning}
-it, and the symbol is then called an @dfn{interned symbol}.
+ If a symbol with the desired name is found, the reader uses that
+symbol. If the obarray does not contain a symbol with that name, the
+reader makes a new symbol and adds it to the obarray. Finding or adding
+a symbol with a certain name is called @dfn{interning} it, and the
+symbol is then called an @dfn{interned symbol}.
+
+ Interning ensures that each obarray has just one symbol with any
+particular name. Other like-named symbols may exist, but not in the
+same obarray. Thus, the reader gets the same symbols for the same
+names, as long as you keep reading with the same obarray.
@cindex symbol equality
@cindex uninterned symbol
- If a symbol is not in the obarray, then there is no way for Lisp to
-find it when its name is read. Such a symbol is called an
-@dfn{uninterned symbol} relative to the obarray. An uninterned symbol
-has all the other characteristics of interned symbols; it has the same
-four cells and they work in the usual way.
+ No obarray contains all symbols; in fact, some symbols are not in any
+obarray. They are called @dfn{uninterned symbols}. An uninterned
+symbol has the same four cells as other symbols; however, the only way
+to gain access to it is by finding it in some other object or as the
+value of a variable.
In Emacs Lisp, an obarray is actually a vector. Each element of the
vector is a bucket; its value is either an interned symbol whose name
@cindex CL note---symbol in obarrays
@quotation
-@b{Common Lisp note:} in Common Lisp, a single symbol may be interned in
+@b{Common Lisp note:} In Common Lisp, a single symbol may be interned in
several obarrays.
@end quotation
@end defvar
@defun mapatoms function &optional obarray
-This function call @var{function} for each symbol in the obarray
+This function calls @var{function} for each symbol in the obarray
@var{obarray}. It returns @code{nil}. If @var{obarray} is omitted, it
defaults to the value of @code{obarray}, the standard obarray for
ordinary symbols.
elements stored in the property list cell of a symbol. Each of the
pairs associates a property name (usually a symbol) with a property or
value. Property lists are generally used to record information about a
-symbol, such as how to compile it, the name of the file where it was
-defined, or perhaps even the grammatical class of the symbol
-(representing a word) in a language understanding system.
+symbol, such as its documentation as a variable, the name of the file
+where it was defined, or perhaps even the grammatical class of the
+symbol (representing a word) in a language-understanding system.
Character positions in a string or buffer can also have property lists.
@xref{Text Properties}.
HCoop / bpt / emacs.git / blobdiff