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comparison man/lispref/numbers.texi @ 4885:6772ce4d982b
Fix hash tables, #'member*, #'assoc*, #'eql compiler macros if bignums
lisp/ChangeLog addition:
2010-01-24 Aidan Kehoe <kehoea@parhasard.net>
Correct the semantics of #'member*, #'eql, #'assoc* in the
presence of bignums; change the integerp byte code to fixnump
semantics.
* bytecomp.el (fixnump, integerp, byte-compile-integerp):
Change the integerp byte code to fixnump; add a byte-compile
method to integerp using fixnump and numberp and avoiding a
funcall most of the time, since in the non-core contexts where
integerp is used, it's mostly distinguishing between fixnums and
things that are not numbers at all.
* byte-optimize.el (side-effect-free-fns, byte-after-unbind-ops)
(byte-compile-side-effect-and-error-free-ops):
Replace the integerp bytecode with fixnump; add fixnump to the
side-effect-free-fns. Add the other extended number type
predicates to the list in passing.
* obsolete.el (floatp-safe): Mark this as obsolete.
* cl.el (eql): Go into more detail in the docstring here. Don't
bother checking whether both arguments are numbers; one is enough,
#'equal will fail correctly if they have distinct types.
(subst): Replace a call to #'integerp (deciding whether to use
#'memq or not) with one to #'fixnump.
Delete most-positive-fixnum, most-negative-fixnum from this file;
they're now always in C, so they can't be modified from Lisp.
* cl-seq.el (member*, assoc*, rassoc*):
Correct these functions in the presence of bignums.
* cl-macs.el (cl-make-type-test): The type test for a fixnum is
now fixnump. Ditch floatp-safe, use floatp instead.
(eql): Correct this compiler macro in the presence of bignums.
(assoc*): Correct this compiler macro in the presence of bignums.
* simple.el (undo):
Change #'integerp to #'fixnump here, since we use #'delq with the
same value as ELT a few lines down.
src/ChangeLog addition:
2010-01-24 Aidan Kehoe <kehoea@parhasard.net>
Fix problems with #'eql, extended number types, and the hash table
implementation; change the Bintegerp bytecode to fixnump semantics
even on bignum builds, since #'integerp can have a fast
implementation in terms of #'fixnump for most of its extant uses,
but not vice-versa.
* lisp.h: Always #include number.h; we want the macros provided in
it, even if the various number types are not available.
* number.h (NON_FIXNUM_NUMBER_P): New macro, giving 1 when its
argument is of non-immediate number type. Equivalent to FLOATP if
WITH_NUMBER_TYPES is not defined.
* elhash.c (lisp_object_eql_equal, lisp_object_eql_hash):
Use NON_FIXNUM_NUMBER_P in these functions, instead of FLOATP,
giving more correct behaviour in the presence of the extended
number types.
* bytecode.c (Bfixnump, execute_optimized_program):
Rename Bintegerp to Bfixnump; change its semantics to reflect the
new name on builds with bignum support.
* data.c (Ffixnump, Fintegerp, syms_of_data, vars_of_data):
Always make #'fixnump available, even on non-BIGNUM builds;
always implement #'integerp in this file, even on BIGNUM builds.
Move most-positive-fixnum, most-negative-fixnum here from
number.c, so they are Lisp constants even on builds without number
types, and attempts to change or bind them error.
Use the NUMBERP and INTEGERP macros even on builds without
extended number types.
* data.c (fixnum_char_or_marker_to_int):
Rename this function from integer_char_or_marker_to_int, to better
reflect the arguments it accepts.
* number.c (Fevenp, Foddp, syms_of_number):
Never provide #'integerp in this file. Remove #'oddp,
#'evenp; their implementations are overridden by those in cl.el.
* number.c (vars_of_number):
most-positive-fixnum, most-negative-fixnum are no longer here.
man/ChangeLog addition:
2010-01-23 Aidan Kehoe <kehoea@parhasard.net>
Generally: be careful to say fixnum, not integer, when talking
about fixed-precision integral types. I'm sure I've missed
instances, both here and in the docstrings, but this is a decent
start.
* lispref/text.texi (Columns):
Document where only fixnums, not integers generally, are accepted.
(Registers):
Remove some ancient char-int confoundance here.
* lispref/strings.texi (Creating Strings, Creating Strings):
Be more exact in describing where fixnums but not integers in
general are accepted.
(Creating Strings): Use a more contemporary example to illustrate
how concat deals with lists including integers about #xFF. Delete
some obsolete documentation on same.
(Char Table Types): Document that only fixnums are accepted as
values in syntax tables.
* lispref/searching.texi (String Search, Search and Replace):
Be exact in describing where fixnums but not integers in general
are accepted.
* lispref/range-tables.texi (Range Tables): Be exact in describing
them; only fixnums are accepted to describe ranges.
* lispref/os.texi (Killing XEmacs, User Identification)
(Time of Day, Time Conversion):
Be more exact about using fixnum where only fixed-precision
integers are accepted.
* lispref/objects.texi (Integer Type): Be more exact (and
up-to-date) about the possible values for
integers. Cross-reference to documentation of the bignum extension.
(Equality Predicates):
(Range Table Type):
(Array Type): Use fixnum, not integer, to describe a
fixed-precision integer.
(Syntax Table Type): Correct some English syntax here.
* lispref/numbers.texi (Numbers): Change the phrasing here to use
fixnum to mean the fixed-precision integers normal in emacs.
Document that our terminology deviates from that of Common Lisp,
and that we're working on it.
(Compatibility Issues): Reiterate the Common Lisp versus Emacs
Lisp compatibility issues.
(Comparison of Numbers, Arithmetic Operations):
* lispref/commands.texi (Command Loop Info, Working With Events):
* lispref/buffers.texi (Modification Time):
Be more exact in describing where fixnums but not integers in
general are accepted.
author | Aidan Kehoe <kehoea@parhasard.net> |
---|---|
date | Sun, 24 Jan 2010 15:21:27 +0000 |
parents | b5e1d4f6b66f |
children | 378a34562cbe |
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4869:e533a9912ef1 | 4885:6772ce4d982b |
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7 @chapter Numbers | 7 @chapter Numbers |
8 @c #### Improve the indexing in this file!!!! | 8 @c #### Improve the indexing in this file!!!! |
9 @cindex integers | 9 @cindex integers |
10 @cindex numbers | 10 @cindex numbers |
11 | 11 |
12 XEmacs supports two to five numeric data types. @dfn{Integers} and | 12 XEmacs supports two to five numeric data types. @dfn{Fixnums} and |
13 @dfn{floating point numbers} are always supported. As a build-time | 13 @dfn{floating point numbers} are always supported. As a build-time |
14 option, @dfn{bignums}, @dfn{ratios}, and @dfn{bigfloats} may be | 14 option, @dfn{bignums}, @dfn{ratios}, and @dfn{bigfloats} may be |
15 enabled on some platforms. | 15 enabled on some platforms. |
16 | 16 |
17 Integers, which are what Common Lisp calls | 17 Fixnums (called just @dfn{integers} in GNU Emacs and older versions |
18 @dfn{fixnums}, are whole numbers such as @minus{}3, 0, #b0111, #xFEED, | 18 of XEmacs) are whole numbers such as @minus{}3, 0, #b0111, #xFEED, |
19 #o744. Their values are exact, and their range is limited. The | 19 #o744. Their values are exact, and their range is limited. The |
20 number prefixes `#b', `#o', and `#x' are supported to represent numbers | 20 number prefixes `#b', `#o', and `#x' are supported to represent numbers |
21 in binary, octal, and hexadecimal notation (or radix). Floating point | 21 in binary, octal, and hexadecimal notation (or radix). Floating point |
22 numbers are numbers with fractional parts, such as @minus{}4.5, 0.0, or | 22 numbers are numbers with fractional parts, such as @minus{}4.5, 0.0, or |
23 2.71828. They can also be expressed in exponential notation: 1.5e2 | 23 2.71828. They can also be expressed in exponential notation: 1.5e2 |
50 that is already a bigfloat. However, when bigfloats of differing | 50 that is already a bigfloat. However, when bigfloats of differing |
51 precision are mixed, the result will always have the larger precision. | 51 precision are mixed, the result will always have the larger precision. |
52 The exact rules are more carefully explained elsewhere | 52 The exact rules are more carefully explained elsewhere |
53 (@pxref{Canonicalization and Contagion}). | 53 (@pxref{Canonicalization and Contagion}). |
54 | 54 |
55 Note that the term ``integer'' is used throughout the XEmacs | 55 Common Lisp terminology and historical Emacs terminology conflict |
56 documentation and code to mean ``fixnum''. This is inconsistent with | 56 here, to an extent. We attempt to use ``fixnum'' and ``integer'' |
57 Common Lisp, and likely to cause confusion. Similarly, ``float'' is | 57 consistently, but older XEmacs and GNU Emacs code and documentation use |
58 used to mean ``fixed precision floating point number'', and the Common | 58 the latter to mean the former. ``Float'' is used in Emacs documentation |
59 Lisp distinctions among @dfn{short-floats}, @dfn{long-floats}, | 59 to mean ``fixed precision floating point number'', and the Common Lisp |
60 @emph{etc.}, and bigfloats (which are not standardized in Common Lisp) | 60 distinctions among @dfn{short-floats}, @dfn{long-floats}, @emph{etc.}, |
61 are not reflected in XEmacs terminology. (Volunteers to fix this in the | 61 and bigfloats (which are not standardized in Common Lisp) are not |
62 XEmacs manuals would be heartily welcomed.) | 62 reflected in XEmacs terminology. We're working on this, but volunteers |
63 to fix it in the XEmacs manuals would be heartily welcomed. | |
63 | 64 |
64 @menu | 65 @menu |
65 * Integer Basics:: Representation and range of integers. | 66 * Integer Basics:: Representation and range of integers. |
66 * Rational Basics:: Representation and range of rational numbers. | 67 * Rational Basics:: Representation and range of rational numbers. |
67 * Float Basics:: Representation and range of floating point. | 68 * Float Basics:: Representation and range of floating point. |
539 @key{RET}}), which will give us platform information. (We do know that | 540 @key{RET}}), which will give us platform information. (We do know that |
540 BSD MP implementations vary across vendors, but how much, we do not know | 541 BSD MP implementations vary across vendors, but how much, we do not know |
541 yet.) | 542 yet.) |
542 | 543 |
543 @item | 544 @item |
544 Terminology is not Common-Lisp-conforming. For example, ``integer'' for | 545 Our documentation's terminology, and our API terminology, is not always |
545 Emacs Lisp means what Common Lisp calls ``fixnum''. This issue is being | 546 Common-Lisp-conforming. Many places use ``integer'' where ``fixnum'' |
546 investigated, but the use of ``integer'' for fixnum is pervasive and may | 547 better reflects what the code accepts or produces; there are similar |
547 cause backward-compatibility and GNU-Emacs-compatibility problems. | 548 issues for the varying types of floating point numbers. Since Emacs |
548 There are similar issues for floating point numbers. Since Emacs Lisp | 549 Lisp has not had a ratio type before, there are no problems there. |
549 has not had a ratio type before, there should be no problems there. | |
550 | 550 |
551 @item | 551 @item |
552 An atom with ratio read syntax now returns a number, not a symbol. | 552 An atom with ratio read syntax now returns a number, not a symbol. |
553 | 553 |
554 @item | 554 @item |
757 @cindex CL note---integers vrs @code{eq} | 757 @cindex CL note---integers vrs @code{eq} |
758 @quotation | 758 @quotation |
759 @b{Common Lisp note:} Comparing numbers in Common Lisp always requires | 759 @b{Common Lisp note:} Comparing numbers in Common Lisp always requires |
760 @code{=} because Common Lisp implements multi-word integers, and two | 760 @code{=} because Common Lisp implements multi-word integers, and two |
761 distinct integer objects can have the same numeric value. XEmacs Lisp | 761 distinct integer objects can have the same numeric value. XEmacs Lisp |
762 can have just one integer object for any given value because it has a | 762 can have just one fixnum object for any given value because it has a |
763 limited range of integer values. | 763 limited range of fixnum values. |
764 @end quotation | 764 @end quotation |
765 | 765 |
766 In addition to numbers, all of the following functions also accept | 766 In addition to numbers, all of the following functions also accept |
767 characters and markers as arguments, and treat them as their number | 767 characters and markers as arguments, and treat them as their number |
768 equivalents. | 768 equivalents. |
912 All of these functions except @code{%} return a floating point value | 912 All of these functions except @code{%} return a floating point value |
913 if any argument is floating. | 913 if any argument is floating. |
914 | 914 |
915 It is important to note that in XEmacs Lisp, arithmetic functions | 915 It is important to note that in XEmacs Lisp, arithmetic functions |
916 do not check for overflow. Thus @code{(1+ 134217727)} may evaluate to | 916 do not check for overflow. Thus @code{(1+ 134217727)} may evaluate to |
917 @minus{}134217728, depending on your hardware. | 917 @minus{}134217728, depending on your hardware and whether your XEmacs |
918 supports bignums. | |
918 | 919 |
919 @defun 1+ number | 920 @defun 1+ number |
920 This function returns @var{number} plus one. @var{number} may be a | 921 This function returns @var{number} plus one. @var{number} may be a |
921 number, character or marker. Markers and characters are converted to | 922 number, character or marker. Markers and characters are converted to |
922 integers. | 923 integers. |