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
comparison
equal deleted inserted replaced
4869:e533a9912ef1 4885:6772ce4d982b
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.