X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Futils.h;h=5f34d02534bcf04e02708853dab8b40adcf5d703;hp=3c33162ec8adc389e58b5617eeafa63082fdcc62;hb=094911eb78cacb6f2877a70c9ac74766df58ccea;hpb=24fe247f9ed16114a765a01c593fec5c4a2f591c diff --git a/ginac/utils.h b/ginac/utils.h index 3c33162e..5f34d025 100644 --- a/ginac/utils.h +++ b/ginac/utils.h @@ -1,9 +1,10 @@ /** @file utils.h * - * Interface to several small and furry utilities. */ + * Interface to several small and furry utilities needed within GiNaC but not + * of any interest to the user of the library. */ /* - * GiNaC Copyright (C) 1999 Johannes Gutenberg University Mainz, Germany + * GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -25,111 +26,222 @@ #include #include +#include #include "config.h" #include "assertion.h" namespace GiNaC { +// This should be obsoleted once is widely deployed. template -string ToString(T const & t) +std::string ToString(const T & t) { - char buf[256]; - ostrstream(buf,sizeof(buf)) << t << ends; - return buf; + char buf[256]; + std::ostrstream(buf,sizeof(buf)) << t << std::ends; + return buf; } +/** Exception class thrown by classes which provide their own series expansion + * to signal that ordinary Taylor expansion is safe. */ +class do_taylor {}; + +/** Exception class thrown when a singularity is encountered. */ +class pole_error : public std::domain_error { +public: + explicit pole_error(const std::string& what_arg, int degree); + int degree(void) const; +private: + int deg; +}; + +// some compilers (e.g. cygwin) define a macro log2, causing confusion +#ifndef log2 unsigned log2(unsigned n); +#endif -int compare_pointers(void const * a, void const * b); +/** Compare two pointers (just to establish some sort of canonical order). + * @return -1, 0, or 1 */ +inline int compare_pointers(const void * a, const void * b) +{ + if (ab) + return 1; + return 0; +} /** Rotate lower 31 bits of unsigned value by one bit to the left - * (upper bits get cleared). */ + * (upper bit gets cleared). */ inline unsigned rotate_left_31(unsigned n) { - // clear highest bit and shift 1 bit to the left - n=(n & 0x7FFFFFFFU) << 1; - - // overflow? clear highest bit and set lowest bit - if (n & 0x80000000U) { - n=(n & 0x7FFFFFFFU) | 0x00000001U; - } - GINAC_ASSERT(n<0x80000000U); - - return n; + // clear highest bit and shift 1 bit to the left + n = (n & 0x7FFFFFFFU) << 1; + + // overflow? clear highest bit and set lowest bit + if (n & 0x80000000U) + n = (n & 0x7FFFFFFFU) | 0x00000001U; + + GINAC_ASSERT(n<0x80000000U); + + return n; } -/** Golden ratio hash function. */ +/** Golden ratio hash function for the 31 least significant bits. */ inline unsigned golden_ratio_hash(unsigned n) { // This function requires arithmetic with at least 64 significant bits -#if SIZEOF_LONG_DOUBLE > 8 - // If "long double" is bigger than 64 bits, we assume that the mantissa - // has at least 64 bits. This is not guaranteed but it's a good guess. - const static long double golden_ratio = .618033988749894848204586834370; - long double m = golden_ratio * n; - return unsigned((m - int(m)) * 0x80000000); -#elif SIZEOF_LONG >= 8 - // "long" has 64 bits, so we prefer it because it might be more efficient - // than "long long" +#if SIZEOF_LONG >= 8 + // So 'long' has 64 bits. Excellent! We prefer it because it might be + // more efficient than 'long long'. unsigned long l = n * 0x4f1bbcddL; return (l & 0x7fffffffU) ^ (l >> 32); #elif SIZEOF_LONG_LONG >= 8 - // This requires ´long long´ (or an equivalent 64 bit type)---which is, - // unfortunately, not ANSI-compliant: - unsigned long long l = n * 0x4f1bbcddLL; + // This requires 'long long' (or an equivalent 64 bit type)---which is, + // unfortunately, not ANSI-C++-compliant. + // (Yet C99 demands it, which is reason for hope.) + unsigned long long l = n * 0x4f1bbcddL; return (l & 0x7fffffffU) ^ (l >> 32); +#elif SIZEOF_LONG_DOUBLE > 8 + // If 'long double' is bigger than 64 bits, we assume that the mantissa + // has at least 64 bits. This is not guaranteed but it's a good guess. + // Unfortunately, it may lead to horribly slow code. + const static long double golden_ratio = .618033988749894848204586834370; + long double m = golden_ratio * n; + return unsigned((m - int(m)) * 0x80000000); #else #error "No 64 bit data type. You lose." #endif } -// modified from stl_algo.h: always do com(*first1,*first2) instead of comp(*first2,*first1) -template -OutputIterator mymerge(InputIterator1 first1, InputIterator1 last1, - InputIterator2 first2, InputIterator2 last2, - OutputIterator result, Compare comp) { - while (first1 != last1 && first2 != last2) { - if (comp(*first1, *first2)) { - *result = *first1; - ++first1; - } - else { - *result = *first2; - ++first2; - } - ++result; - } - return copy(first2, last2, copy(first1, last1, result)); +// Compute the sign of a permutation of a vector of things. +template +int permutation_sign(std::vector s) +{ + if (s.size() < 2) + return 0; + int sigma = 1; + for (typename std::vector::iterator i=s.begin(); i!=s.end()-1; ++i) { + for (typename std::vector::iterator j=i+1; j!=s.end(); ++j) { + if (*i == *j) + return 0; + if (*i > *j) { + iter_swap(i,j); + sigma = -sigma; + } + } + } + return sigma; } -// like merge(), but three lists with *last2<*first3 -template -OutputIterator mymerge3(InputIterator1 first1, InputIterator1 last1, - InputIterator2 first2, InputIterator2 last2, - InputIterator3 first3, InputIterator3 last3, - OutputIterator result, Compare comp) { - while (first1 != last1 && first2 != last2) { - if (comp(*first1, *first2)) { - *result = *first1; - ++first1; - } - else { - *result = *first2; - ++first2; - } - ++result; - } - - if (first1==last1) { - // list1 empty, copy rest of list2, then list3 - return copy(first3, last3, copy(first2, last2, result)); - } else { - // list2 empty, merge rest of list1 with list3 - return mymerge(first1,last1,first3,last3,result,comp); - } -} +void append_exvector_to_exvector(exvector & dest, const exvector & source); + +// Collection of `construct on first use' wrappers for safely avoiding +// internal object replication without running into the `static +// initialization order fiasco'. This chest of numbers helps speed up +// the library but should not be used outside it since it is +// potentially confusing. + +class numeric; +class ex; + +const numeric & _num_120(void); // -120 +const ex & _ex_120(void); +const numeric & _num_60(void); // -60 +const ex & _ex_60(void); +const numeric & _num_48(void); // -48 +const ex & _ex_48(void); +const numeric & _num_30(void); // -30 +const ex & _ex_30(void); +const numeric & _num_25(void); // -25 +const ex & _ex_25(void); +const numeric & _num_24(void); // -24 +const ex & _ex_24(void); +const numeric & _num_20(void); // -20 +const ex & _ex_20(void); +const numeric & _num_18(void); // -18 +const ex & _ex_18(void); +const numeric & _num_15(void); // -15 +const ex & _ex_15(void); +const numeric & _num_12(void); // -12 +const ex & _ex_12(void); +const numeric & _num_11(void); // -11 +const ex & _ex_11(void); +const numeric & _num_10(void); // -10 +const ex & _ex_10(void); +const numeric & _num_9(void); // -9 +const ex & _ex_9(void); +const numeric & _num_8(void); // -8 +const ex & _ex_8(void); +const numeric & _num_7(void); // -7 +const ex & _ex_7(void); +const numeric & _num_6(void); // -6 +const ex & _ex_6(void); +const numeric & _num_5(void); // -5 +const ex & _ex_5(void); +const numeric & _num_4(void); // -4 +const ex & _ex_4(void); +const numeric & _num_3(void); // -3 +const ex & _ex_3(void); +const numeric & _num_2(void); // -2 +const ex & _ex_2(void); +const numeric & _num_1(void); // -1 +const ex & _ex_1(void); +const numeric & _num_1_2(void); // -1/2 +const ex & _ex_1_2(void); +const numeric & _num_1_3(void); // -1/3 +const ex & _ex_1_3(void); +const numeric & _num_1_4(void); // -1/4 +const ex & _ex_1_4(void); +const numeric & _num0(void); // 0 +const ex & _ex0(void); +const numeric & _num1_4(void); // 1/4 +const ex & _ex1_4(void); +const numeric & _num1_3(void); // 1/3 +const ex & _ex1_3(void); +const numeric & _num1_2(void); // 1/2 +const ex & _ex1_2(void); +const numeric & _num1(void); // 1 +const ex & _ex1(void); +const numeric & _num2(void); // 2 +const ex & _ex2(void); +const numeric & _num3(void); // 3 +const ex & _ex3(void); +const numeric & _num4(void); // 4 +const ex & _ex4(void); +const numeric & _num5(void); // 5 +const ex & _ex5(void); +const numeric & _num6(void); // 6 +const ex & _ex6(void); +const numeric & _num7(void); // 7 +const ex & _ex7(void); +const numeric & _num8(void); // 8 +const ex & _ex8(void); +const numeric & _num9(void); // 9 +const ex & _ex9(void); +const numeric & _num10(void); // 10 +const ex & _ex10(void); +const numeric & _num11(void); // 11 +const ex & _ex11(void); +const numeric & _num12(void); // 12 +const ex & _ex12(void); +const numeric & _num15(void); // 15 +const ex & _ex15(void); +const numeric & _num18(void); // 18 +const ex & _ex18(void); +const numeric & _num20(void); // 20 +const ex & _ex20(void); +const numeric & _num24(void); // 24 +const ex & _ex24(void); +const numeric & _num25(void); // 25 +const ex & _ex25(void); +const numeric & _num30(void); // 30 +const ex & _ex30(void); +const numeric & _num48(void); // 48 +const ex & _ex48(void); +const numeric & _num60(void); // 60 +const ex & _ex60(void); +const numeric & _num120(void); // 120 +const ex & _ex120(void); } // namespace GiNaC