/************************************************************************/ /* */ /* Centre for Speech Technology Research */ /* University of Edinburgh, UK */ /* Copyright (c) 1996,1997 */ /* All Rights Reserved. */ /* */ /* Permission is hereby granted, free of charge, to use and distribute */ /* this software and its documentation without restriction, including */ /* without limitation the rights to use, copy, modify, merge, publish, */ /* distribute, sublicense, and/or sell copies of this work, and to */ /* permit persons to whom this work is furnished to do so, subject to */ /* the following conditions: */ /* 1. The code must retain the above copyright notice, this list of */ /* conditions and the following disclaimer. */ /* 2. Any modifications must be clearly marked as such. */ /* 3. Original authors' names are not deleted. */ /* 4. The authors' names are not used to endorse or promote products */ /* derived from this software without specific prior written */ /* permission. */ /* */ /* THE UNIVERSITY OF EDINBURGH AND THE CONTRIBUTORS TO THIS WORK */ /* DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING */ /* ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT */ /* SHALL THE UNIVERSITY OF EDINBURGH NOR THE CONTRIBUTORS BE LIABLE */ /* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES */ /* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN */ /* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, */ /* ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF */ /* THIS SOFTWARE. */ /* */ /************************************************************************/ /* Author: Richard Caley (rjc@cstr.ed.ac.uk) */ /* Date: Tue Apr 29 1997 */ /************************************************************************/ /* */ /* Example of hash table use. */ /* */ /************************************************************************/ #include #include #include #include "EST_THash.h" #include "EST_String.h" // a very boring thing to do to a pair, see map below static void look_at(EST_String &s, int &l) { (void)s; (void)l; cout << "."; } int main(void) { // Map from strings to numbers, hashed by default method. EST_TStringHash lengths(100); lengths.add_item("fred", 4); lengths.add_item("bill", 4); lengths.add_item("harry", 5); const EST_TStringHash const_lengths = lengths; // Map from ints to floats. Note, the other way around is alomst // certainly a mistake. EST_THash logs(100); logs.add_item(12, log(12.0)); logs.add_item(34, log(34.0)); cout << "length of `fred' = " << lengths.val("fred") << "\n"; cout << "log of 34' = " << logs.val(34) << "\n"; // remove items with the remove_item() method. logs.remove_item(34); cout << "now don't know log of 34' = " << logs.val(34) << "\n"; // the second argument to val can be used to // ask whether the result was actually found. Useful // when the dummy value returned for an unknown key is // actually a valid value for the application. int found; float val = logs.val(123, found); cout << "log of 123"; if (found) cout << " = " << val; else cout << " not found"; cout << "\n"; // dump puts out a human readable version of the table for debugging lengths.dump(cout); // map calls a function on each pair, in this case just prints one dot per // pair (see definition of look_at earlier). lengths.map(look_at); cout << "\n"; // We can step through the table with an iterator. EST_THash::Entries them; for(them.begin(const_lengths); them; them++) { cout << them->k << " " << them->v << " "; } cout << "\n"; EST_THash::RwEntries rwthem; for(rwthem.begin(lengths); rwthem; rwthem++) { rwthem->v *= 3; cout << rwthem->k << " " << rwthem->v << " "; } cout << "\n"; return 0; } template <> int EST_THash::Dummy_Key = 0; template <> float EST_THash::Dummy_Value = 0.0; #if defined(INSTANTIATE_TEMPLATES) #include "../base_class/EST_THash.cc" Instantiate_THash(int,float) #endif