Line data Source code
1 : /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 : * -------------------------------------------------------------------------- *
3 : * Lepton *
4 : * -------------------------------------------------------------------------- *
5 : * This is part of the Lepton expression parser originating from *
6 : * Simbios, the NIH National Center for Physics-Based Simulation of *
7 : * Biological Structures at Stanford, funded under the NIH Roadmap for *
8 : * Medical Research, grant U54 GM072970. See https://simtk.org. *
9 : * *
10 : * Portions copyright (c) 2013-2016 Stanford University and the Authors. *
11 : * Authors: Peter Eastman *
12 : * Contributors: *
13 : * *
14 : * Permission is hereby granted, free of charge, to any person obtaining a *
15 : * copy of this software and associated documentation files (the "Software"), *
16 : * to deal in the Software without restriction, including without limitation *
17 : * the rights to use, copy, modify, merge, publish, distribute, sublicense, *
18 : * and/or sell copies of the Software, and to permit persons to whom the *
19 : * Software is furnished to do so, subject to the following conditions: *
20 : * *
21 : * The above copyright notice and this permission notice shall be included in *
22 : * all copies or substantial portions of the Software. *
23 : * *
24 : * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
25 : * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
26 : * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
27 : * THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
28 : * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
29 : * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE *
30 : * USE OR OTHER DEALINGS IN THE SOFTWARE. *
31 : * -------------------------------------------------------------------------- *
32 : +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
33 : #ifndef __PLUMED_lepton_ParsedExpression_h
34 : #define __PLUMED_lepton_ParsedExpression_h
35 :
36 : /* -------------------------------------------------------------------------- *
37 : * lepton *
38 : * -------------------------------------------------------------------------- *
39 : * This is part of the lepton expression parser originating from *
40 : * Simbios, the NIH National Center for Physics-Based Simulation of *
41 : * Biological Structures at Stanford, funded under the NIH Roadmap for *
42 : * Medical Research, grant U54 GM072970. See https://simtk.org. *
43 : * *
44 : * Portions copyright (c) 2009=2021 Stanford University and the Authors. *
45 : * Authors: Peter Eastman *
46 : * Contributors: *
47 : * *
48 : * Permission is hereby granted, free of charge, to any person obtaining a *
49 : * copy of this software and associated documentation files (the "Software"), *
50 : * to deal in the Software without restriction, including without limitation *
51 : * the rights to use, copy, modify, merge, publish, distribute, sublicense, *
52 : * and/or sell copies of the Software, and to permit persons to whom the *
53 : * Software is furnished to do so, subject to the following conditions: *
54 : * *
55 : * The above copyright notice and this permission notice shall be included in *
56 : * all copies or substantial portions of the Software. *
57 : * *
58 : * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
59 : * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
60 : * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
61 : * THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
62 : * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
63 : * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE *
64 : * USE OR OTHER DEALINGS IN THE SOFTWARE. *
65 : * -------------------------------------------------------------------------- */
66 :
67 : #include "ExpressionTreeNode.h"
68 : #include "windowsIncludes.h"
69 : #include <map>
70 : #include <string>
71 :
72 : namespace PLMD {
73 : namespace lepton {
74 :
75 : class CompiledExpression;
76 : class ExpressionProgram;
77 :
78 : /**
79 : * This class represents the result of parsing an expression. It provides methods for working with the
80 : * expression in various ways, such as evaluating it, getting the tree representation of the expresson, etc.
81 : */
82 :
83 2040903 : class LEPTON_EXPORT ParsedExpression {
84 : public:
85 : /**
86 : * Create an uninitialized ParsedExpression. This exists so that ParsedExpressions can be put in STL containers.
87 : * Doing anything with it will produce an exception.
88 : */
89 : ParsedExpression();
90 : /**
91 : * Create a ParsedExpression. Normally you will not call this directly. Instead, use the Parser class
92 : * to parse expression.
93 : */
94 : ParsedExpression(const ExpressionTreeNode& rootNode);
95 : /**
96 : * Get the root node of the expression's abstract syntax tree.
97 : */
98 : const ExpressionTreeNode& getRootNode() const;
99 : /**
100 : * Evaluate the expression. If the expression involves any variables, this method will throw an exception.
101 : */
102 : double evaluate() const;
103 : /**
104 : * Evaluate the expression.
105 : *
106 : * @param variables a map specifying the values of all variables that appear in the expression. If any
107 : * variable appears in the expression but is not included in this map, an exception
108 : * will be thrown.
109 : */
110 : double evaluate(const std::map<std::string, double>& variables) const;
111 : /**
112 : * Create a new ParsedExpression which produces the same result as this one, but is faster to evaluate.
113 : */
114 : ParsedExpression optimize() const;
115 : /**
116 : * Create a new ParsedExpression which produces the same result as this one, but is faster to evaluate.
117 : *
118 : * @param variables a map specifying values for a subset of variables that appear in the expression.
119 : * All occurrences of these variables in the expression are replaced with the values
120 : * specified.
121 : */
122 : ParsedExpression optimize(const std::map<std::string, double>& variables) const;
123 : /**
124 : * Create a new ParsedExpression which is the analytic derivative of this expression with respect to a
125 : * particular variable.
126 : *
127 : * @param variable the variable with respect to which the derivate should be taken
128 : */
129 : ParsedExpression differentiate(const std::string& variable) const;
130 : /**
131 : * Create an ExpressionProgram that represents the same calculation as this expression.
132 : */
133 : ExpressionProgram createProgram() const;
134 : /**
135 : * Create a CompiledExpression that represents the same calculation as this expression.
136 : */
137 : CompiledExpression createCompiledExpression() const;
138 : /**
139 : * Create a new ParsedExpression which is identical to this one, except that the names of some
140 : * variables have been changed.
141 : *
142 : * @param replacements a map whose keys are the names of variables, and whose values are the
143 : * new names to replace them with
144 : */
145 : ParsedExpression renameVariables(const std::map<std::string, std::string>& replacements) const;
146 : private:
147 : static double evaluate(const ExpressionTreeNode& node, const std::map<std::string, double>& variables);
148 : static ExpressionTreeNode preevaluateVariables(const ExpressionTreeNode& node, const std::map<std::string, double>& variables);
149 : static ExpressionTreeNode precalculateConstantSubexpressions(const ExpressionTreeNode& node, std::map<int, ExpressionTreeNode>& nodeCache);
150 : static ExpressionTreeNode substituteSimplerExpression(const ExpressionTreeNode& node, std::map<int, ExpressionTreeNode>& nodeCache);
151 : static ExpressionTreeNode differentiate(const ExpressionTreeNode& node, const std::string& variable, std::map<int, ExpressionTreeNode>& nodeCache);
152 : static bool isConstant(const ExpressionTreeNode& node);
153 : static double getConstantValue(const ExpressionTreeNode& node);
154 : static ExpressionTreeNode renameNodeVariables(const ExpressionTreeNode& node, const std::map<std::string, std::string>& replacements);
155 : ExpressionTreeNode rootNode;
156 : };
157 :
158 : LEPTON_EXPORT std::ostream& operator<<(std::ostream& out, const ExpressionTreeNode& node);
159 :
160 : LEPTON_EXPORT std::ostream& operator<<(std::ostream& out, const ParsedExpression& exp);
161 :
162 : } // namespace lepton
163 : } // namespace PLMD
164 :
165 : #endif /*LEPTON_PARSED_EXPRESSION_H_*/
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