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Tests for module 'unictype/joiningtype-byname'.
* modules/unictype/joiningtype-byname-tests: New file.
* tests/unictype/test-joiningtype_byname.c: New file.

author | Bruno Haible <bruno@clisp.org> |
---|---|

date | Mon, 21 Mar 2011 22:58:36 +0100 |

parents | 97fc9a21a8fb |

children | 8250f2777afc |

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@node gcd @section gcd: greatest common divisor @findex gcd @c Copyright (C) 2006, 2009-2011 Free Software Foundation, Inc. @c Permission is granted to copy, distribute and/or modify this document @c under the terms of the GNU Free Documentation License, Version 1.3 or @c any later version published by the Free Software Foundation; with no @c Invariant Sections, with no Front-Cover Texts, and with no Back-Cover @c Texts. A copy of the license is included in the ``GNU Free @c Documentation License'' file as part of this distribution. The @code{gcd} function returns the greatest common divisor of two numbers @code{a > 0} and @code{b > 0}. It is the caller's responsibility to ensure that the arguments are non-zero. If you need a gcd function for an integer type larger than @samp{unsigned long}, you can include the @file{gcd.c} implementation file with parametrization. The parameters are: @itemize @bullet @item WORD_T Define this to the unsigned integer type that you need this function for. @item GCD Define this to the name of the function to be created. @end itemize The created function has the prototype @smallexample WORD_T GCD (WORD_T a, WORD_T b); @end smallexample If you need the least common multiple of two numbers, it can be computed like this: @code{lcm(a,b) = (a / gcd(a,b)) * b} or @code{lcm(a,b) = a * (b / gcd(a,b))}. Avoid the formula @code{lcm(a,b) = (a * b) / gcd(a,b)} because - although mathematically correct - it can yield a wrong result, due to integer overflow. In some applications it is useful to have a function taking the gcd of two signed numbers. In this case, the gcd function result is usually normalized to be non-negative (so that two gcd results can be compared in magnitude or compared against 1, etc.). Note that in this case the prototype of the function has to be @smallexample unsigned long gcd (long a, long b); @end smallexample and not @smallexample long gcd (long a, long b); @end smallexample because @code{gcd(LONG_MIN,LONG_MIN) = -LONG_MIN = LONG_MAX + 1} does not fit into a signed @samp{long}.