Mercurial > hg > xemacs-beta
changeset 5677:febc025c4e0c
Adopt GNU's ## syntax for the interned symbol with name "".
src/ChangeLog addition:
2012-08-06 Aidan Kehoe <kehoea@parhasard.net>
* lread.c (read1):
* print.c (print_symbol):
Adopt GNU's ## syntax for the interned symbol with the zero-length
name.
man/ChangeLog addition:
2012-08-06 Aidan Kehoe <kehoea@parhasard.net>
* lispref/symbols.texi (Symbol Components):
Document the new syntax of ## for the symbol with name "" interned
in obarray.
| author | Aidan Kehoe <kehoea@parhasard.net> |
|---|---|
| date | Mon, 06 Aug 2012 13:07:55 +0100 |
| parents | dede3f658f8e |
| children | b0d40183ac79 |
| files | man/ChangeLog man/lispref/symbols.texi src/ChangeLog src/lread.c src/print.c |
| diffstat | 5 files changed, 32 insertions(+), 10 deletions(-) [+] |
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--- a/man/ChangeLog Sat Aug 04 23:26:26 2012 +0900 +++ b/man/ChangeLog Mon Aug 06 13:07:55 2012 +0100 @@ -1,3 +1,9 @@ +2012-08-06 Aidan Kehoe <kehoea@parhasard.net> + + * lispref/symbols.texi (Symbol Components): + Document the new syntax of ## for the symbol with name "" interned + in obarray. + 2012-08-02 Stephen J. Turnbull <stephen@xemacs.org> * XEmacs 21.5.32 "habanero" is released.
--- a/man/lispref/symbols.texi Sat Aug 04 23:26:26 2012 +0900 +++ b/man/lispref/symbols.texi Mon Aug 06 13:07:55 2012 +0100 @@ -73,9 +73,15 @@ Since symbols are represented textually by their names, it is important not to have two symbols with the same name. The Lisp reader ensures this: every time it reads a symbol, it looks for an existing symbol with -the specified name before it creates a new one. (In XEmacs Lisp, -this lookup uses a hashing algorithm and an obarray; see @ref{Creating -Symbols}.) +the specified name before it creates a new one. In XEmacs Lisp, +this lookup uses an hashing algorithm and an obarray; see @ref{Creating +Symbols}. In Emacs Lisp, the symbol with the zero-length name has the +special print syntax @code{##}: + +@example +(intern "") + @result{} ## +@end example In normal usage, the function cell usually contains a function or macro, as that is what the Lisp interpreter expects to see there
--- a/src/ChangeLog Sat Aug 04 23:26:26 2012 +0900 +++ b/src/ChangeLog Mon Aug 06 13:07:55 2012 +0100 @@ -1,3 +1,10 @@ +2012-08-06 Aidan Kehoe <kehoea@parhasard.net> + + * lread.c (read1): + * print.c (print_symbol): + Adopt GNU's ## syntax for the interned symbol with the zero-length + name. + 2012-08-02 Stephen J. Turnbull <stephen@xemacs.org> * XEmacs 21.5.32 "habanero" is released.
--- a/src/lread.c Sat Aug 04 23:26:26 2012 +0900 +++ b/src/lread.c Mon Aug 06 13:07:55 2012 +0100 @@ -2654,6 +2654,8 @@ goto retry; } + /* The interned symbol with the empty name. */ + case '#': return intern (""); case '$': return Vload_file_name_internal; /* bit vectors */ case '*': return read_bit_vector (readcharfun);
--- a/src/print.c Sat Aug 04 23:26:26 2012 +0900 +++ b/src/print.c Mon Aug 06 13:07:55 2012 +0100 @@ -2375,8 +2375,6 @@ print_symbol (Lisp_Object obj, Lisp_Object printcharfun, int escapeflag) { /* This function can GC */ - /* #### Bug!! (intern "") isn't printed in some distinguished way */ - /* #### (the reader also loses on it) */ Lisp_Object name = symbol_name (XSYMBOL (obj)); Bytecount size = XSTRING_LENGTH (name); struct gcpro gcpro1, gcpro2; @@ -2390,12 +2388,15 @@ GCPRO2 (obj, printcharfun); - if (print_gensym) + if (print_gensym && !IN_OBARRAY (obj)) { - if (!IN_OBARRAY (obj)) - { - write_ascstring (printcharfun, "#:"); - } + write_ascstring (printcharfun, "#:"); + } + else if (0 == size) + { + /* Compatible with GNU, but not with Common Lisp, where the syntax for + this symbol is ||. */ + write_ascstring (printcharfun, "##"); } /* Does it look like an integer or a float? */