diff options
Diffstat (limited to 'lisp/emacs-lisp/cl.el')
| -rw-r--r-- | lisp/emacs-lisp/cl.el | 56 |
1 files changed, 46 insertions, 10 deletions
diff --git a/lisp/emacs-lisp/cl.el b/lisp/emacs-lisp/cl.el index 526475eb1bd..971024fcbba 100644 --- a/lisp/emacs-lisp/cl.el +++ b/lisp/emacs-lisp/cl.el @@ -1,6 +1,6 @@ ;;; cl.el --- Common Lisp extensions for Emacs -;; Copyright (C) 1993, 2001-2011 Free Software Foundation, Inc. +;; Copyright (C) 1993, 2001-2012 Free Software Foundation, Inc. ;; Author: Dave Gillespie <daveg@synaptics.com> ;; Version: 2.02 @@ -333,15 +333,51 @@ always returns nil." (defvar *random-state* (vector 'cl-random-state-tag -1 30 (cl-random-time))) -;; The following are actually set by cl-float-limits. -(defconst most-positive-float nil) -(defconst most-negative-float nil) -(defconst least-positive-float nil) -(defconst least-negative-float nil) -(defconst least-positive-normalized-float nil) -(defconst least-negative-normalized-float nil) -(defconst float-epsilon nil) -(defconst float-negative-epsilon nil) +(defconst most-positive-float nil + "The largest value that a Lisp float can hold. +If your system supports infinities, this is the largest finite value. +For IEEE machines, this is approximately 1.79e+308. +Call `cl-float-limits' to set this.") + +(defconst most-negative-float nil + "The largest negative value that a Lisp float can hold. +This is simply -`most-positive-float'. +Call `cl-float-limits' to set this.") + +(defconst least-positive-float nil + "The smallest value greater than zero that a Lisp float can hold. +For IEEE machines, it is about 4.94e-324 if denormals are supported, +or 2.22e-308 if they are not. +Call `cl-float-limits' to set this.") + +(defconst least-negative-float nil + "The smallest value less than zero that a Lisp float can hold. +This is simply -`least-positive-float'. +Call `cl-float-limits' to set this.") + +(defconst least-positive-normalized-float nil + "The smallest normalized Lisp float greater than zero. +This is the smallest value for which IEEE denormalization does not lose +precision. For IEEE machines, this value is about 2.22e-308. +For machines that do not support the concept of denormalization +and gradual underflow, this constant equals `least-positive-float'. +Call `cl-float-limits' to set this.") + +(defconst least-negative-normalized-float nil + "The smallest normalized Lisp float less than zero. +This is simply -`least-positive-normalized-float'. +Call `cl-float-limits' to set this.") + +(defconst float-epsilon nil + "The smallest positive float that adds to 1.0 to give a distinct value. +Adding a number less than this to 1.0 returns 1.0 due to roundoff. +For IEEE machines, epsilon is about 2.22e-16. +Call `cl-float-limits' to set this.") + +(defconst float-negative-epsilon nil + "The smallest positive float that subtracts from 1.0 to give a distinct value. +For IEEE machines, it is about 1.11e-16. +Call `cl-float-limits' to set this.") ;;; Sequence functions. |