Improve the implementation, documentation of #'labels, #'flet. lisp/ChangeLog addition: 2011-09-07 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el: * bytecomp.el (for-effect): Move this earlier in the file, it's referenced in byte-compile-initial-macro-environment. * bytecomp.el (byte-compile-initial-macro-environment): In the byte-compile-macro-environment definition for #'labels, put off the compiling the lambda bodies until the point where the rest of the form is being compiled, allowing the lambda bodies to access appropriate values for byte-compile-bound-variables, and reducing excessive warning about free variables. Add a byte-compile-macro-environment definition for #'flet. This modifies byte-compile-function-environment appropriately, and warns about bindings of functions that have macro definitions in the current environment, about functions that have byte codes, and about functions that have byte-compile methods (which may not do what the user wants at runtime). * bytecomp.el (byte-compile-funcall): If FUNCTION is constant, call #'byte-compile-callargs-warn if that's appropriate, giving warnings about problems with calling functions bound with #'labels. * cl-macs.el: * cl-macs.el (flet): Mention the main difference from Common Lisp, that the bindings are dynamic, not lexical. Counsel the use of #'labels, not #'flet, for this and other reasons. Explain the limited single use case for #'flet. Cross-reference to bytecomp.el in a comment. * cl-macs.el (labels): Go into detail on which functions may be called from where. Explain how to access the function definition of a label within FORM. Add a comment cross-referencing to bytecomp.el. man/ChangeLog addition: 2011-09-07 Aidan Kehoe <kehoea@parhasard.net> * cl.texi (Function Bindings): Move #'labels first, describe it in more detail, explaining that it is to be preferred over #'flet, and explaining why. Explain that dynamic bindings with #'flet will also not work when functions are accessed through their bytecodes.

/*
   Copyright (C) 1995 Free Software Foundation, Inc.

This file is part of XEmacs.

XEmacs is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.

XEmacs is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with XEmacs.  If not, see <http://www.gnu.org/licenses/>. */

/* Synched up with: Not really in FSF. */

#ifndef INCLUDED_sysfloat_h_
#define INCLUDED_sysfloat_h_

#if defined(LINUX) && !(defined (__GLIBC__) && (__GLIBC__ >= 2))
/* These are redefined (correctly, but differently) in values.h.  */
#undef INTBITS
#undef LONGBITS
#undef SHORTBITS
#endif

#include <math.h>

#ifdef WIN32_NATIVE
/* A quirky way to obtain logb prototype */
#include <float.h>
#define logb _logb
#endif

#ifdef HAVE_MATHERR
/* Work around symbol conflict on Linux/glibc */
#ifndef DOMAIN
/* SysV matherr is not defined if _BSD_SOURCE is used, and on Linux X11 */
/* is compiled with _BSD_SOURCE which can also change the size of other */
/* types.  The configure test for matherr is broken. */
/* Bah.  Good riddance to bad rubbish. */
#undef HAVE_MATHERR
#endif
#endif

#ifdef NO_MATHERR
#undef HAVE_MATHERR
#endif

#ifdef HAVE_MATHERR
# ifdef FLOAT_CHECK_ERRNO
#  undef FLOAT_CHECK_ERRNO
# endif
# ifdef FLOAT_CHECK_DOMAIN
#  undef FLOAT_CHECK_DOMAIN
# endif
#endif

#ifndef NO_FLOAT_CHECK_ERRNO
#define FLOAT_CHECK_ERRNO
#endif

#ifdef FLOAT_CHECK_ERRNO
# include <errno.h>
#endif

#ifndef isnan
# define isnan(x) ((x) != (x))
#endif

#endif /* INCLUDED_sysfloat_h_ */