From 071f5e609c5601165a07d68fb077f88140592c7f Mon Sep 17 00:00:00 2001 From: Marco Bodrato Date: Fri, 4 May 2018 21:43:34 +0200 Subject: mpq_*_str: document and support the correct base range --- ChangeLog | 5 +++++ doc/gmp.texi | 26 +++++++++++++++++++------- mpq/get_str.c | 13 +++++++++---- 3 files changed, 33 insertions(+), 11 deletions(-) diff --git a/ChangeLog b/ChangeLog index 6d027e6b4..86885c20a 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2018-05-04 Marco Bodrato + + * doc/gmp.texi (mpq_*_str): Document the full base allowed range. + * mpq/get_str.c: Make all bases either work or return an error. + 2018-04-27 Niels Möller * mpn/generic/div_q.c (mpn_div_q): Replace dead code with ASSERT. diff --git a/doc/gmp.texi b/doc/gmp.texi index 9ebf2b082..15ce9ad85 100644 --- a/doc/gmp.texi +++ b/doc/gmp.texi @@ -14,7 +14,7 @@ This manual describes how to install and use the GNU multiple precision arithmetic library, version @value{VERSION}. -Copyright 1991, 1993-2016 Free Software Foundation, Inc. +Copyright 1991, 1993-2016, 2018 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later @@ -4365,9 +4365,14 @@ is exact. @end deftypefun @deftypefun {char *} mpq_get_str (char *@var{str}, int @var{base}, const mpq_t @var{op}) -Convert @var{op} to a string of digits in base @var{base}. The base may vary -from 2 to 36. The string will be of the form @samp{num/den}, or if the -denominator is 1 then just @samp{num}. +Convert @var{op} to a string of digits in base @var{base}. The base argument +may vary from 2 to 62 or from @minus{}2 to @minus{}36. The string will be of +the form @samp{num/den}, or if the denominator is 1 then just @samp{num}. + +For @var{base} in the range 2..36, digits and lower-case letters are used; for +@minus{}2..@minus{}36, digits and upper-case letters are used; for 37..62, +digits, upper-case letters, and lower-case letters (in that significance order) +are used. If @var{str} is @code{NULL}, the result string is allocated using the current allocation function (@pxref{Custom Allocation}). The block will be @@ -4535,9 +4540,15 @@ See also @ref{Formatted Output} and @ref{Formatted Input}. @deftypefun size_t mpq_out_str (FILE *@var{stream}, int @var{base}, const mpq_t @var{op}) Output @var{op} on stdio stream @var{stream}, as a string of digits in base -@var{base}. The base may vary from 2 to 36. Output is in the form +@var{base}. The base argument may vary from 2 to 62 or from @minus{}2 to +@minus{}36. Output is in the form @samp{num/den} or if the denominator is 1 then just @samp{num}. +For @var{base} in the range 2..36, digits and lower-case letters are used; for +@minus{}2..@minus{}36, digits and upper-case letters are used; for 37..62, +digits, upper-case letters, and lower-case letters (in that significance order) +are used. + Return the number of bytes written, or if an error occurred, return 0. @end deftypefun @@ -4553,9 +4564,10 @@ space is not permitted within the string. If the input might not be in canonical form, then @code{mpq_canonicalize} must be called (@pxref{Rational Number Functions}). -The @var{base} can be between 2 and 36, or can be 0 in which case the leading +The @var{base} can be between 2 and 62, or can be 0 in which case the leading characters of the string determine the base, @samp{0x} or @samp{0X} for -hexadecimal, @samp{0} for octal, or decimal otherwise. The leading characters +hexadecimal, @code{0b} and @code{0B} for binary, @samp{0} for octal, or +decimal otherwise. The leading characters are examined separately for the numerator and denominator of a fraction, so for instance @samp{0x10/11} is @math{16/11}, whereas @samp{0x10/0x11} is @math{16/17}. diff --git a/mpq/get_str.c b/mpq/get_str.c index 881340fb9..d0cfb58dd 100644 --- a/mpq/get_str.c +++ b/mpq/get_str.c @@ -1,6 +1,6 @@ /* mpq_get_str -- mpq to string conversion. -Copyright 2001, 2002, 2006, 2011 Free Software Foundation, Inc. +Copyright 2001, 2002, 2006, 2011, 2018 Free Software Foundation, Inc. This file is part of the GNU MP Library. @@ -47,6 +47,8 @@ mpq_get_str (char *str, int base, mpq_srcptr q) /* This is an overestimate since we don't bother checking how much of the high limbs of num and den are used. +2 for rounding up the chars per bit of num and den. +3 for sign, slash and '\0'. */ + if (ABS(base) < 2) + base = 10; DIGITS_IN_BASE_PER_LIMB (str_alloc, ABSIZ(NUM(q)) + SIZ(DEN(q)), ABS(base)); str_alloc += 6; @@ -64,9 +66,12 @@ mpq_get_str (char *str, int base, mpq_srcptr q) ASSERT (len == strlen(str)); ASSERT (str_alloc == 0 || len+1 <= str_alloc); - ASSERT (len+1 <= /* size recommended to applications */ - mpz_sizeinbase (mpq_numref(q), ABS(base)) + - mpz_sizeinbase (mpq_denref(q), ABS(base)) + 3); + ASSERT (len+1 <= 3 + /* size recommended to applications */ + (ABS(base) < 2 ? + mpz_sizeinbase (mpq_numref(q), 10) + + mpz_sizeinbase (mpq_denref(q), 10) + : mpz_sizeinbase (mpq_numref(q), ABS(base)) + + mpz_sizeinbase (mpq_denref(q), ABS(base)))); if (str_alloc != 0) __GMP_REALLOCATE_FUNC_MAYBE_TYPE (str, str_alloc, len+1, char); -- cgit v1.2.1