gadgetlib2::FConst Class Reference

#include <variable.hpp>

Inheritance diagram for gadgetlib2::FConst:

Collaboration diagram for gadgetlib2::FConst:

Public Member Functions
	FConst (const FConst &src)
virtual FConst &	operator= (const long n)
virtual FConst &	operator= (const FConst &src)
virtual ::std::string	asString () const
virtual FieldType	fieldType () const
virtual FConst &	operator+= (const FElemInterface &other)
virtual FConst &	operator-= (const FElemInterface &other)
virtual FConst &	operator*= (const FElemInterface &other)
virtual bool	operator== (const FElemInterface &other) const
virtual bool	operator== (const FConst &other) const
virtual bool	operator== (const long n) const
virtual FElemInterfacePtr	clone () const
virtual FElemInterfacePtr	inverse () const
long	asLong () const
int	getBit (unsigned int i) const
virtual FElemInterface &	power (long exponent)
Public Member Functions inherited from gadgetlib2::FElemInterface
virtual	~FElemInterface ()

Friends
class	FElem

Detailed Description

A field agnostic constant. All fields have constants 1 and 0 and this class allows us to hold an element agnostically while the context field is not known. For example, when given the very useful expression '1 - x' where x is a field agnostic formal variable, we must store the constant '1' without knowing over which field this expression will be evaluated. Constants can also hold integer values, which will be evaluated if possible, in runtime. For instance the expression '42 + x' will be evaluated in runtime in the trivial way when working over the prime characteristic Galois Field GF_43 but will cause a runtime error when evaluated over a GF2 extension field in which '42' has no obvious meaning, other than being the answer to life, the universe and everything.

Definition at line 189 of file variable.hpp.

Constructor & Destructor Documentation

FConst()

gadgetlib2::FConst::FConst ( const FConst &  src )

inline

Definition at line 196 of file variable.hpp.

: contents_(src.contents_) {}

Member Function Documentation

asLong()

long gadgetlib2::FConst::asLong ( ) const

inlinevirtual

Implements gadgetlib2::FElemInterface.

Definition at line 232 of file variable.hpp.

{ return contents_; }

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asString()

virtual ::std::string gadgetlib2::FConst::asString ( ) const

inlinevirtual

Implements gadgetlib2::FElemInterface.

Definition at line 207 of file variable.hpp.

    {
        return GADGETLIB2_FMT("%ld", contents_);
    }

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clone()

virtual FElemInterfacePtr gadgetlib2::FConst::clone ( ) const

inlinevirtual

Returns

a unique_ptr to a new copy of the element

Implements gadgetlib2::FElemInterface.

Definition at line 225 of file variable.hpp.

    {
        return FElemInterfacePtr(new FConst(*this));
    }

fieldType()

virtual FieldType gadgetlib2::FConst::fieldType ( ) const

inlinevirtual

Implements gadgetlib2::FElemInterface.

Definition at line 211 of file variable.hpp.

{ return AGNOSTIC; }

getBit()

int gadgetlib2::FConst::getBit ( unsigned int  i ) const

inlinevirtual

Implements gadgetlib2::FElemInterface.

Definition at line 233 of file variable.hpp.

    {
        libff::UNUSED(i);
        GADGETLIB_FATAL("Cannot get bit from FConst.");
    }

inverse()

FElemInterfacePtr gadgetlib2::FConst::inverse ( ) const

virtual

Returns

a unique_ptr to a new copy of the element's multiplicative inverse

Implements gadgetlib2::FElemInterface.

Definition at line 176 of file variable.cpp.

{
    GADGETLIB_FATAL("Attempted to invert an FConst element.");
}

operator*=()

FConst & gadgetlib2::FConst::operator*= ( const FElemInterface &  other )

virtual

Implements gadgetlib2::FElemInterface.

Definition at line 170 of file variable.cpp.

{
    contents_ *= dynamic_cast<const FConst &>(other).contents_;
    return *this;
}

operator+=()

FConst & gadgetlib2::FConst::operator+= ( const FElemInterface &  other )

virtual

Implements gadgetlib2::FElemInterface.

Definition at line 158 of file variable.cpp.

{
    contents_ += dynamic_cast<const FConst &>(other).contents_;
    return *this;
}

operator-=()

FConst & gadgetlib2::FConst::operator-= ( const FElemInterface &  other )

virtual

Implements gadgetlib2::FElemInterface.

Definition at line 164 of file variable.cpp.

{
    contents_ -= dynamic_cast<const FConst &>(other).contents_;
    return *this;
}

operator=() [1/2]

virtual FConst& gadgetlib2::FConst::operator= ( const FConst &  src )

inlinevirtual

FConst will be field agnostic, allowing us to hold values such as 0 and 1 without knowing the underlying field. This assignment operator will convert to the correct field element.

Implements gadgetlib2::FElemInterface.

Definition at line 202 of file variable.hpp.

    {
        contents_ = src.contents_;
        return *this;
    }

operator=() [2/2]

virtual FConst& gadgetlib2::FConst::operator= ( const long  n )

inlinevirtual

Implements gadgetlib2::FElemInterface.

Definition at line 197 of file variable.hpp.

    {
        contents_ = n;
        return *this;
    }

operator==() [1/3]

virtual bool gadgetlib2::FConst::operator== ( const FConst &  other ) const

inlinevirtual

Implements gadgetlib2::FElemInterface.

Definition at line 219 of file variable.hpp.

    {
        return contents_ == other.contents_;
    }

operator==() [2/3]

virtual bool gadgetlib2::FConst::operator== ( const FElemInterface &  other ) const

inlinevirtual

Implements gadgetlib2::FElemInterface.

Definition at line 215 of file variable.hpp.

    {
        return other == *this;
    }

operator==() [3/3]

virtual bool gadgetlib2::FConst::operator== ( const long  n ) const

inlinevirtual

This operator is not always mathematically well defined. 'n' will be checked in runtime for fields in which integer values are not well defined.

Implements gadgetlib2::FElemInterface.

Definition at line 223 of file variable.hpp.

{ return contents_ == n; }

power()

FElemInterface & gadgetlib2::FConst::power ( long  exponent )

virtual

Implements gadgetlib2::FElemInterface.

Definition at line 181 of file variable.cpp.

{
    contents_ = 0.5 + ::std::pow(double(contents_), double(exponent));
    return *this;
}

Friends And Related Function Documentation

FElem

friend class FElem

friend

Definition at line 240 of file variable.hpp.

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The documentation for this class was generated from the following files:

• /home/runner/work/libsnark/libsnark/libsnark/gadgetlib2/variable.hpp
• /home/runner/work/libsnark/libsnark/libsnark/gadgetlib2/variable.cpp