atom_assignings.h

// Copyright (C) 2006, Ondra Kamenik

// $Id: atom_assignings.h 149 2007-04-30 02:11:46Z okamenik $

#ifndef OGP_ATOM_ASSIGNINGS_H
#define OGP_ATOM_ASSIGNINGS_H

#include "static_atoms.h"
#include "formula_parser.h"
#include "atom_substitutions.h"

#include <vector>
#include <map>

namespace ogp {

	class AtomAsgnEvaluator;

	/** This class represents atom assignments used in parameters
	 * settings and initval initialization. It maintains atoms of the
	 * all expressions on the right hand side, the parsed formulas of
	 * the right hand sides, and the information about the left hand
	 * sides. See documentation to the order member below. */
	class AtomAssignings {
		friend class AtomAsgnEvaluator;
	protected:
		typedef std::map<const char*, int, ltstr> Tvarintmap;
		/** All atoms which should be sufficient for formulas at the
		 * right hand sides. The atoms should be filled with names
		 * (preregistered). This is a responsibility of the caller. */
		StaticAtoms& atoms;
		/** The formulas of right hand sides. */
		FormulaParser expr;
		/** Name storage of the names from left hand sides. */
		NameStorage left_names;
		/** Information on left hand sides. This maps a name to the
		 * index of its assigned expression in expr. More than one
		 * name may reference to the same expression. */
		Tvarintmap lname2expr;
		/** Information on left hand sides. If order[i] >= 0, then it
		 * says that i-th expression in expr is assigned to atom with
		 * order[i] tree index. */
		std::vector<int> order;
	public:
		/** Construct the object using the provided static atoms. */
		AtomAssignings(StaticAtoms& a) : atoms(a), expr(atoms)
			{}
		/** Make a copy with provided reference to (posibly different)
		 * static atoms. */
		AtomAssignings(const AtomAssignings& aa, StaticAtoms& a);
		virtual ~AtomAssignings()
			{}
		/** Parse the assignments from the given string. */
		void parse(int length, const char* stream);
		/** Process a syntax error from bison. */
		void error(const char* mes);
		/** Add an assignment of the given name to the given
		 * double. Can be called by a user, anytime. */
		void add_assignment_to_double(const char* name, double val);
		/** Add an assignment. Called from assign.y. */
		void add_assignment(int asgn_off, const char* str, int name_len,
							int right_off, int right_len);
		/** This applies old2new map (possibly from atom
		 * substitutions) to this object. It registers new variables
		 * in the atoms, and adds the expressions to expr, and left
		 * names to lname2expr. The information about dynamical part
		 * of substitutions is ignored, since we are now in the static
		 * world. */
		void apply_subst(const AtomSubstitutions::Toldnamemap& mm);
		/** Debug print. */
		void print() const;
	};

	/** This class basically evaluates the atom assignments
	 * AtomAssignings, so it inherits from ogp::FormulaEvaluator. It
	 * is also a storage for the results of the evaluation stored as a
	 * vector, so the class inherits from std::vector<double> and
	 * ogp::FormulaEvalLoader. As the expressions for atoms are
	 * evaluated, the results are values for atoms which will be
	 * used in subsequent evaluations. For this reason, the class
	 * inherits also from AtomValues. */
	class AtomAsgnEvaluator : public FormulaEvalLoader,
							  public AtomValues,
							  protected FormulaEvaluator,
							  public std::vector<double> {
	protected:
		typedef std::map<int, double> Tusrvalmap;
		Tusrvalmap user_values;
		const AtomAssignings& aa;
	public:
		AtomAsgnEvaluator(const AtomAssignings& a)
			: FormulaEvaluator(a.expr),
			  std::vector<double>(a.expr.nformulas()), aa(a) {}
		virtual ~AtomAsgnEvaluator() {}
		/** This sets all initial values to NaNs, all constants and
		 * all values set by user by call set_value. This is called by
		 * FormulaEvaluator::eval() method, which is called by eval()
		 * method passing this argument as AtomValues. So the
		 * ogp::EvalTree will be always this->etree. */
		void setValues(EvalTree& et) const;
		/** User setting of the values. For example in initval,
		 * parameters are known and should be set to their values. In
		 * constrast endogenous variables are set initially to NaNs by
		 * AtomValues::setValues. */
		void set_user_value(const char* name, double val);
		/** This sets the result of i-th expression in aa to res, and
		 * also checks whether the i-th expression is an atom. If so,
		 * it sets the value of the atom in ogp::EvalTree
		 * this->etree. */
		void load(int i, double res);
		/** After the user values have been set, the assignments can
		 * be evaluated. For this purpose we have eval() method. The
		 * result is that this object as std::vector<double> will
		 * contain the values. It is ordered given by formulas in
		 * expr. */
		void eval()
			{FormulaEvaluator::eval(*this, *this);}
		/** This returns a value for a given name. If the name is not
		 * found among atoms, or there is no assignment for the atom,
		 * NaN is returned. */
		double get_value(const char* name) const;
	};

};

#endif

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