------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S Y S T E M . S T R I N G _ H A S H -- -- -- -- S p e c -- -- -- -- Copyright (C) 2009-2019, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. -- -- -- -- As a special exception under Section 7 of GPL version 3, you are granted -- -- additional permissions described in the GCC Runtime Library Exception, -- -- version 3.1, as published by the Free Software Foundation. -- -- -- -- You should have received a copy of the GNU General Public License and -- -- a copy of the GCC Runtime Library Exception along with this program; -- -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- -- . -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- This package provides a generic hashing function over strings, suitable for -- use with a string keyed hash table. In particular, it is the basis for the -- string hash functions in Ada.Containers. -- -- The algorithm used here is not appropriate for applications that require -- cryptographically strong hashes, or for application which wish to use very -- wide hash values as pseudo unique identifiers. In such cases please refer -- to GNAT.SHA1 and GNAT.MD5. -- -- Note: this package is in the System hierarchy so that it can be directly -- be used by other predefined packages. User access to this package is via -- a renaming of this package in GNAT.String_Hash (file g-strhas.ads). package System.String_Hash is pragma Pure; generic type Char_Type is (<>); -- The character type composing the key string type type Key_Type is array (Positive range <>) of Char_Type; -- The string type to use as a hash key type Hash_Type is mod <>; -- The type to be returned as a hash value. This must be a 32-bit -- unsigned type with full range 0 .. 2**32-1, no other type is allowed -- for this instantiation (checked in the body by Compile_Time_Error). function Hash (Key : Key_Type) return Hash_Type; pragma Inline (Hash); -- Compute a hash value for a key end System.String_Hash;