Lucas de Vries
28 lines
977 B
C++
28 lines
977 B
C++
#pragma once
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#include <string>
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typedef double varInterpreter(void*,const std::string*);
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typedef double varIndexInterpreter(void*,int);
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typedef int varIndexConverter(const std::string*);
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double nullConverter(void*,const std::string*);
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struct FormulaError {
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std::string msg;
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FormulaError(const char* message) : msg(message) {}
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FormulaError(std::string message) : msg(message) {}
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};
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class Formula {
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public:
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//Evaluates the formula
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//Variables in the formula will be passed to <VarConverter>, which receives
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//the name of the variable, and the <UserPointer> passed to evaluate
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virtual double evaluate(varInterpreter VarConverter = nullConverter, void* UserPointer = nullptr, varIndexInterpreter VarIndexConverter = 0) = 0;
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virtual ~Formula() {}
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//Creates a formula from infix notation
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//Can throw FormulaError if there is an error in the expression
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static Formula* fromInfix(const char* expression, varIndexConverter VarConverter = 0, bool catchErrors = true);
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};
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;
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