/* * Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005 * Heikki Tauriainen * * 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 the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include #include "FormulaRandomizer.h" #include "Random.h" namespace Ltl { /****************************************************************************** * * Function definitions for class FormulaRandomizer. * *****************************************************************************/ /* ========================================================================= */ void FormulaRandomizer::reset() /* ---------------------------------------------------------------------------- * * Description: Sets the random formula generation parameters to their * default values. * * Arguments: None. * * Returns: Nothing. * * ------------------------------------------------------------------------- */ { number_of_available_variables = 5; size = 5; max_size = 5; propositional_symbol_priorities.clear(); short_formula_operators.clear(); long_formula_operators.clear(); propositional_symbol_priorities.push_back(make_pair(-1, 0)); short_formula_operators.push_back(make_pair(-1, 0)); long_formula_operators.push_back(make_pair(-1, 0)); number_of_generated_formulas = 0; proposition_statistics.clear(); symbol_statistics.clear(); } /* ========================================================================= */ LtlFormula* FormulaRandomizer::generate() /* ---------------------------------------------------------------------------- * * Description: Generates a random (newly allocated) LtlFormula using the * parameters stored in `this' object. * * Arguments: None. * * Returns: A pointer to the generated formula. * * ------------------------------------------------------------------------- */ { unsigned long int target_size(size); if (max_size > size) target_size += LRAND(0, max_size - size + 1); number_of_generated_formulas++; return recGenerate(target_size); } /* ========================================================================= */ LtlFormula* FormulaRandomizer::recGenerate(unsigned long int target_size) /* ---------------------------------------------------------------------------- * * Description: Implementation of the recursive random formula generation * algorithm. * * Arguments: target_size -- Size of the formula to be generated. * * Returns: A pointer to the generated formula. * * ------------------------------------------------------------------------- */ { vector::const_iterator symbol_priority; LtlFormula* formula; long int x; /* * Select a list of allowable symbols according to the target size. If the * size is 1, only atomic propositions and Boolean constants are allowed * If the size is 2, only unary operators are allowed. Otherwise select the * symbols from the set of unary and binary operators. */ switch (target_size) { case 1 : x = LRAND(0, propositional_symbol_priorities[0].second); symbol_priority = propositional_symbol_priorities.begin(); break; case 2 : x = LRAND(0, short_formula_operators[0].second); symbol_priority = short_formula_operators.begin(); break; default : x = LRAND(0, long_formula_operators[0].second); symbol_priority = long_formula_operators.begin(); break; } /* * Using the selected list, choose a random symbol in the list using the * priority distribution of the different symbols in the list. The list * consists of pairs. The first element of the list does * not correspond to any symbol, however; instead, it gives the sum of the * priorities of the symbols in the list. */ ++symbol_priority; while (x >= symbol_priority->second) { x -= symbol_priority->second; ++symbol_priority; } symbol_statistics[symbol_priority->first]++; switch (symbol_priority->first) { case LTL_ATOM : { unsigned long int atom = LRAND(0, number_of_available_variables); proposition_statistics[atom]++; formula = &Atom::construct(atom); break; } case LTL_TRUE : formula = &True::construct(); break; case LTL_FALSE : formula = &False::construct(); break; case LTL_NEGATION : formula = &Not::construct(recGenerate(target_size - 1)); break; case LTL_NEXT : formula = &Next::construct(recGenerate(target_size - 1)); break; case LTL_FINALLY : formula = &Finally::construct(recGenerate(target_size - 1)); break; case LTL_GLOBALLY : formula = &Globally::construct(recGenerate(target_size - 1)); break; default : { unsigned long int s = LRAND(1, target_size - 1); LtlFormula* g = recGenerate(s); LtlFormula* h = recGenerate(target_size - s - 1); switch (symbol_priority->first) { case LTL_CONJUNCTION : formula = &And::construct(g, h); break; case LTL_DISJUNCTION : formula = &Or::construct(g, h); break; case LTL_IMPLICATION : formula = &Imply::construct(g, h); break; case LTL_EQUIVALENCE : formula = &Equiv::construct(g, h); break; case LTL_XOR : formula = &Xor::construct(g, h); break; case LTL_UNTIL : formula = &Until::construct(g, h); break; case LTL_V : formula = &V::construct(g, h); break; case LTL_WEAK_UNTIL : formula = &WeakUntil::construct(g, h); break; case LTL_STRONG_RELEASE : formula = &StrongRelease::construct(g, h); break; default : /* LTL_BEFORE */ formula = &Before::construct(g, h); break; } } } return formula; } }