143 lines
3.3 KiB
C
143 lines
3.3 KiB
C
/*
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----
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This file is part of SECONDO.
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Copyright (C) 2004, University in Hagen, Department of Computer Science,
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Database Systems for New Applications.
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SECONDO is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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SECONDO is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with SECONDO; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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----
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3 The Tree
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This pure c file provides a struct tree representing an operator tree
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for special boolean expressions related to the 9 intersection model.
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The reason for not using c++ is that this code should be used in a
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environment created by bison. Unfortunately, bison has no support
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for c++.
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*/
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#ifndef TREE_H
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#define TREE_H
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/*
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1.1 The Data Structure
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*/
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struct tree{
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int type;
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int value;
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int defined;
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struct tree* son1;
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struct tree* son2;
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};
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/*
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1.2 Some definitions
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Here some variables are defined to make this code
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easier to handle.
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*/
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enum VARIABLES {ii=256,ib=128,ie=64,
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bi=32, bb=16, be=8,
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ei=4, eb=2, ee=1};
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enum TYPES {CONSTANT, VARIABLE, OP1, OP2};
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/*
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1.3 Creation of Types
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The following functions create a new tree from the arguments.
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It should be clear from the names, what the functions do.
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Note that each of the functions allocates memory. You have to
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ensure, that this memory is deallocates after use.
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*/
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struct tree* createConstant(int value);
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struct tree* createVariable(int value);
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struct tree* createAnd(struct tree* s1, struct tree* s2);
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struct tree* createOr(struct tree* s1, struct tree* s2);
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struct tree* createXor(struct tree* s1, struct tree* s2);
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struct tree* createConditional(struct tree* s1, struct tree* s2);
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struct tree* createBiconditional(struct tree* s1, struct tree* s2);
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struct tree* createNot(struct tree* s1);
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/*
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1.4 Deallocating Memory
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This function deallocates the memory occupied by the tree and all
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subtrees of it.
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*/
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void destroyTree(struct tree* victim);
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/*
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1.5 Eval Functions
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This functions checks wether the given 9 intersection matrix
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described by its matrix number fulfils the conditions given in
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the tree.
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*/
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int evalTree(struct tree* t, unsigned short number);
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/*
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1.6 Print Function
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This function can be used for debugging purposes. It prints out the
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tree.
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*/
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void printTree(struct tree* t);
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/*
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1.7 Parse function
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This function parses the given string. If the parsing is succsessful,
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the tree is returned as the second argument. If not, the tree remains
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unchanged and the result will be 0.
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Note that this function is defined in the TreeParser file instead in
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the Tree.c file.
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*/
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int parseString(const char* S,struct tree** t);
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/*
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1.8 GetLastMessage
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This function returns the last occured error message if available.
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If not, NULL is returned. Don't forget to deallocate the memory
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used by the result.
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*/
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char* GetLastMessage();
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#endif
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