Make expressions immutable and improve performance

include/fintamath/core/IMathObject.hpp

@@ -36,6 +36,10 @@ class IMathObject {
   virtual MathObjectClass getClass() const noexcept = 0;
 
   friend bool operator==(const IMathObject &lhs, const IMathObject &rhs) {
+    if (&lhs == &rhs) {
+      return true;
+    }
+
     return lhs.equalsAbstract(rhs);
   }
 

include/fintamath/core/IMathObjectCRTP.hpp

@@ -19,6 +19,10 @@ class IMathObjectCRTP_ : public IMathObject {
   }
 
   bool operator==(const I_MATH_OBJECT_CRTP &rhs) const {
+    if (this == &rhs) {
+      return true;
+    }
+
     return equals(cast<Derived>(rhs));
   }
 

include/fintamath/expressions/Expression.hpp

@@ -19,6 +19,7 @@
 #include "fintamath/functions/IFunction.hpp"
 #include "fintamath/functions/IOperator.hpp"
 #include "fintamath/literals/Variable.hpp"
+#include "fintamath/numbers/Real.hpp"
 
 namespace fintamath {
 
@@ -78,29 +79,20 @@ class Expression : public IExpressionCRTP<Expression> {
 
   Expression(int64_t val);
 
-  std::string toString() const override;
-
   const std::shared_ptr<IFunction> &getFunction() const override;
 
   const ArgumentPtrVector &getChildren() const override;
 
-  void setChildren(const ArgumentPtrVector &childVect) override;
+  std::string toString() const override;
 
-  void setVariables(const std::vector<std::pair<Variable, ArgumentPtr>> &varsToVals) override;
+  std::unique_ptr<IMathObject> toMinimalObject() const override;
 
-  void setVariable(const Variable &var, const Expression &val);
+  friend Expression approximate(const Expression &rhs, unsigned precision);
 
   template <typename Function>
   static void registerExpressionConstructor(ExpressionConstructor constructor);
 
-protected:
-  ArgumentPtr simplify() const override;
-
 private:
-  void simplifyMutable() const;
-
-  void updateStringMutable() const;
-
   static detail::TermVector tokensToTerms(detail::TokenVector &tokens);
 
   static detail::ObjectStack termsToObjects(detail::TermVector &terms);
@@ -147,20 +139,16 @@ class Expression : public IExpressionCRTP<Expression> {
 
   friend std::unique_ptr<IMathObject> parseRawExpr(const std::string &str);
 
-  friend Expression approximate(const Expression &rhs, unsigned precision);
-
   static ExpressionMaker &getExpressionMaker();
 
 private:
-  mutable ArgumentPtr child;
+  ArgumentPtr child;
 
-  mutable ArgumentPtrVector childrenCached = {{}};
-
-  mutable std::string stringCached;
-
-  mutable bool isSimplified = false;
+  mutable ArgumentPtrVector childrenCached;
 };
 
+Expression approximate(const Expression &rhs, unsigned precision = Real::getPrecisionStatic());
+
 std::unique_ptr<IMathObject> parseRawExpr(const std::string &str);
 
 template <typename Function>

include/fintamath/expressions/ExpressionFunctions.hpp

@@ -103,8 +103,7 @@ Expression negInf();
 
 Expression complexInf();
 
+// TODO! move to Expression
 Expression solve(const Expression &rhs);
 
-extern Expression approximate(const Expression &rhs, unsigned precision = Real::getPrecision());
-
 }

include/fintamath/expressions/ExpressionUtils.hpp

@@ -29,23 +29,6 @@ ArgumentPtr useSimplifyFunctions(const std::vector<SimplifyFunction> &simplFuncs
   return {};
 }
 
-ArgumentPtr simplifyUndefined(const IFunction &func, const std::same_as<ArgumentPtr> auto &...args) {
-  ArgumentPtr res;
-
-  if ((is<Undefined>(args) || ...)) {
-    static const MathObjectClass undefinedReturnType = Undefined{}.getReturnClass();
-    const MathObjectClass funcReturnType = func.getReturnClass();
-
-    if (is(undefinedReturnType, funcReturnType) ||
-        is(funcReturnType, undefinedReturnType)) {
-
-      res = Undefined{}.clone();
-    }
-  }
-
-  return res;
-}
-
 bool isInfinity(const ArgumentPtr &arg);
 
 bool isMulInfinity(const ArgumentPtr &arg);

include/fintamath/expressions/IExpression.hpp

@@ -22,6 +22,22 @@ namespace fintamath {
 class IExpression : public IMathObject {
   FINTAMATH_PARENT_CLASS_BODY(IExpression, IMathObject)
 
+protected:
+  enum class State : uint8_t {
+    Unknown,
+    PreSimplify,
+    Simplify,
+    Solve,
+    Approximate,
+  };
+
+private:
+  struct CallFunctionCached {
+    ArgumentPtr value;
+    std::optional<unsigned> precision;
+    bool areArgsPrecise = true;
+  };
+
 public:
   using VariableSet = std::set<Variable, ToStringComparator<std::less<>>>;
 
@@ -30,45 +46,48 @@ class IExpression : public IMathObject {
 
   virtual const ArgumentPtrVector &getChildren() const = 0;
 
-  virtual void setChildren(const ArgumentPtrVector &childVect) = 0;
+  const VariableSet &getVariables() const;
 
-  VariableSet getVariables() const;
-
-  virtual void setVariables(const std::vector<std::pair<Variable, ArgumentPtr>> &varsToVals);
-
-  std::unique_ptr<IMathObject> toMinimalObject() const final;
+  std::unique_ptr<IMathObject> toMinimalObject() const override;
 
   virtual const std::shared_ptr<IFunction> &getOutputFunction() const;
 
-protected:
-  virtual ArgumentPtr simplify() const;
+  std::string toString() const override;
 
+protected:
   virtual ArgumentPtr preSimplify() const;
 
-  virtual ArgumentPtr postSimplify() const;
+  virtual ArgumentPtr simplify() const;
 
   virtual ArgumentPtr approximate() const;
 
-  virtual ArgumentPtr setPrecision(unsigned precision, const Integer &maxInt) const;
+  virtual ArgumentPtr toState(State newState) const;
 
-  static void simplifyChild(ArgumentPtr &child);
+  State getState() const;
+
+  ArgumentPtr callFunction() const;
 
   static void preSimplifyChild(ArgumentPtr &child);
 
-  static void postSimplifyChild(ArgumentPtr &child);
+  static void simplifyChild(ArgumentPtr &child);
 
   static void approximateChild(ArgumentPtr &child);
 
-  static void setPrecisionChild(ArgumentPtr &child, unsigned precision, const Integer &maxInt);
+  static void callFunctionChild(ArgumentPtr &child);
 
-  static ArgumentPtr callFunction(const IFunction &func, const ArgumentPtrVector &argPtrs);
+  static void toStateChild(ArgumentPtr &child, State newState);
 
 private:
+  ArgumentPtr simplifyUndefined() const;
+
   static std::unique_ptr<INumber> convertToApproximated(const INumber &num);
 
-  static std::unique_ptr<INumber> convertToApproximated(const INumber &num, unsigned precision, const Integer &maxInt);
+private:
+  mutable std::optional<VariableSet> variablesCached;
+
+  mutable std::optional<CallFunctionCached> callFunctionCached;
 
-  static ArgumentPtrVector convertToApproximatedNumbers(const ArgumentPtrVector &args);
+  mutable State state = State::Unknown;
 };
 
 template <typename Derived>

include/fintamath/expressions/interfaces/IBinaryExpression.hpp

@@ -19,13 +19,11 @@ class IBinaryExpression : public IExpression {
 public:
   explicit IBinaryExpression(const IFunction &inFunc, ArgumentPtr lhs, ArgumentPtr rhs);
 
-  std::string toString() const override;
-
   const std::shared_ptr<IFunction> &getFunction() const final;
 
   const ArgumentPtrVector &getChildren() const final;
 
-  void setChildren(const ArgumentPtrVector &childVect) final;
+  std::string toString() const override;
 
 protected:
   using SimplifyFunction = std::function<ArgumentPtr(const IFunction &, const ArgumentPtr &, const ArgumentPtr &)>;
@@ -34,14 +32,9 @@ class IBinaryExpression : public IExpression {
 
   virtual SimplifyFunctionVector getFunctionsForPreSimplify() const;
 
-  virtual SimplifyFunctionVector getFunctionsForPostSimplify() const;
+  virtual SimplifyFunctionVector getFunctionsForSimplify() const;
 
-  ArgumentPtr preSimplify() const override;
-
-  ArgumentPtr postSimplify() const override;
-
-private:
-  ArgumentPtr simplifyRec(bool isPostSimplify) const;
+  ArgumentPtr toState(State newState) const override;
 
 protected:
   std::shared_ptr<IFunction> func;
@@ -51,7 +44,7 @@ class IBinaryExpression : public IExpression {
   ArgumentPtr rhsChild;
 
 private:
-  mutable ArgumentPtrVector childrenCached = {{}, {}};
+  mutable ArgumentPtrVector childrenCached;
 };
 
 template <typename Derived>

include/fintamath/expressions/interfaces/IPolynomExpression.hpp

@@ -21,13 +21,11 @@ class IPolynomExpression : public IExpression {
 public:
   explicit IPolynomExpression(const IFunction &inFunc, ArgumentPtrVector args);
 
-  std::string toString() const override;
-
   const std::shared_ptr<IFunction> &getFunction() const final;
 
   const ArgumentPtrVector &getChildren() const final;
 
-  void setChildren(const ArgumentPtrVector &childVect) final;
+  std::string toString() const override;
 
 protected:
   using SimplifyFunction = std::function<ArgumentPtr(const IFunction &, const ArgumentPtr &, const ArgumentPtr &)>;
@@ -36,28 +34,24 @@ class IPolynomExpression : public IExpression {
 
   virtual SimplifyFunctionVector getFunctionsForPreSimplify() const;
 
-  virtual SimplifyFunctionVector getFunctionsForPostSimplify() const;
+  virtual SimplifyFunctionVector getFunctionsForSimplify() const;
 
   virtual std::string childToString(const IOperator &oper, const ArgumentPtr &inChild, const ArgumentPtr &prevChild) const;
 
   ArgumentPtr preSimplify() const override;
 
-  ArgumentPtr postSimplify() const override;
-
   virtual bool isTermOrderInversed() const noexcept;
 
   virtual bool isComparableOrderInversed() const noexcept;
 
   virtual std::strong_ordering compare(const ArgumentPtr &lhs, const ArgumentPtr &rhs) const;
 
 private:
-  void simplifyRec(bool isPostSimplify);
-
-  void simplifyChildren(bool isPostSimplify);
+  ArgumentPtr toState(State newState) const override;
 
-  void compress();
+  void compress(ArgumentPtrVector &newChildren) const;
 
-  void sort();
+  void sort(ArgumentPtrVector &newChildren) const;
 
 protected:
   std::shared_ptr<IFunction> func;

include/fintamath/expressions/interfaces/IUnaryExpression.hpp

@@ -19,13 +19,11 @@ class IUnaryExpression : public IExpression {
 public:
   explicit IUnaryExpression(const IFunction &inFunc, ArgumentPtr rhs);
 
-  std::string toString() const override;
-
   const std::shared_ptr<IFunction> &getFunction() const final;
 
   const ArgumentPtrVector &getChildren() const override;
 
-  void setChildren(const ArgumentPtrVector &childVect) override;
+  std::string toString() const override;
 
 protected:
   using SimplifyFunction = std::function<ArgumentPtr(const IFunction &, const ArgumentPtr &)>;
@@ -34,22 +32,18 @@ class IUnaryExpression : public IExpression {
 
   virtual SimplifyFunctionVector getFunctionsForPreSimplify() const;
 
-  virtual SimplifyFunctionVector getFunctionsForPostSimplify() const;
-
-  ArgumentPtr preSimplify() const override;
-
-  ArgumentPtr postSimplify() const override;
+  virtual SimplifyFunctionVector getFunctionsForSimplify() const;
 
 protected:
   std::shared_ptr<IFunction> func;
 
   ArgumentPtr child;
 
 private:
-  ArgumentPtr simplifyRec(bool isPostSimplify) const;
+  ArgumentPtr toState(State newState) const override;
 
 private:
-  mutable ArgumentPtrVector childrenCached = {{}};
+  mutable ArgumentPtrVector childrenCached;
 };
 
 template <typename Derived>

include/fintamath/numbers/Complex.hpp

@@ -48,7 +48,7 @@ class Complex : public INumberCRTP<Complex> {
 
   std::unique_ptr<IMathObject> toMinimalObject() const override;
 
-  bool isPrecise() const noexcept override;
+  std::optional<unsigned> getPrecision() const noexcept override;
 
   bool isComplex() const noexcept override;
 

include/fintamath/numbers/INumber.hpp

@@ -2,6 +2,7 @@
 
 #include <concepts>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 
@@ -17,8 +18,8 @@ class INumber : public IComparable {
   FINTAMATH_PARENT_CLASS_BODY(INumber, IComparable)
 
 public:
-  virtual bool isPrecise() const noexcept {
-    return true;
+  virtual std::optional<unsigned> getPrecision() const noexcept {
+    return {};
   }
 
   virtual bool isComplex() const noexcept {