purify::ExprBuilder Class Reference

Small runtime builder that flattens affine combinations into one expression. More...

#include <expr.hpp>

Public Member Functions
ExprBuilder &	reserve (std::size_t terms)
	Reserves storage for approximately terms linear slots.
ExprBuilder &	add (const FieldElement &value)
	Adds a constant field term to the pending affine expression.
ExprBuilder &	add (std::int64_t value)
	Adds an integer constant term to the pending affine expression.
ExprBuilder &	add_term (Symbol symbol, const FieldElement &scale)
	Adds one scaled symbolic variable term.
ExprBuilder &	add (const Expr &expr)
	Adds an existing expression with implicit coefficient one.
ExprBuilder &	subtract (const Expr &expr)
	Subtracts an existing expression with implicit coefficient minus one.
ExprBuilder &	add_scaled (const Expr &expr, const FieldElement &scale)
	Adds an existing expression scaled by a field element.
ExprBuilder &	add_scaled (const Expr &expr, std::int64_t scale)
	Adds an existing expression scaled by an integer constant.
Expr	build ()
	Materializes the flattened affine expression.

Static Public Member Functions
static ExprBuilder	reserved (std::size_t terms)
	Returns a builder with storage reserved for approximately terms linear slots.

Detailed Description

This avoids repeated intermediate Expr allocations in gadgets that know they are constructing a linear combination of existing expressions.

Definition at line 170 of file expr.hpp.

Member Function Documentation

add() [1/3]

ExprBuilder & purify::ExprBuilder::add

(

const Expr &

expr

)

Definition at line 187 of file expr.cpp.

References purify::Expr::constant(), and purify::Expr::linear().

add() [2/3]

ExprBuilder & purify::ExprBuilder::add

(

const FieldElement &

value

)

Definition at line 171 of file expr.cpp.

Referenced by add(), add_scaled(), purify::circuit_1bit(), purify::circuit_2bit(), purify::circuit_3bit(), purify::circuit_combine(), purify::circuit_ec_add(), and purify::circuit_ec_add_x().

add() [3/3]

ExprBuilder & purify::ExprBuilder::add

(

std::int64_t

value

)

Definition at line 176 of file expr.cpp.

References add(), and purify::FieldElement::from_int().

add_scaled() [1/2]

ExprBuilder & purify::ExprBuilder::add_scaled	(	const Expr &	expr,
		const FieldElement &	scale
	)

Definition at line 214 of file expr.cpp.

References add(), purify::Expr::constant(), purify::FieldElement::from_int(), purify::FieldElement::is_one(), purify::FieldElement::is_zero(), purify::Expr::linear(), and subtract().

Referenced by add_scaled(), purify::circuit_1bit(), purify::circuit_2bit(), purify::circuit_3bit(), and purify::circuit_combine().

add_scaled() [2/2]

ExprBuilder & purify::ExprBuilder::add_scaled	(	const Expr &	expr,
		std::int64_t	scale
	)

Definition at line 238 of file expr.cpp.

References add_scaled(), and purify::FieldElement::from_int().

add_term()

ExprBuilder & purify::ExprBuilder::add_term	(	Symbol	symbol,
		const FieldElement &	scale
	)

Definition at line 180 of file expr.cpp.

References purify::FieldElement::is_zero().

build()

Expr purify::ExprBuilder::build

(

)

Definition at line 242 of file expr.cpp.

Referenced by purify::circuit_1bit(), purify::circuit_2bit(), purify::circuit_3bit(), purify::circuit_combine(), purify::circuit_ec_add(), and purify::circuit_ec_add_x().

reserve()

ExprBuilder & purify::ExprBuilder::reserve

(

std::size_t

terms

)

Definition at line 166 of file expr.cpp.

reserved()

ExprBuilder purify::ExprBuilder::reserved ( std::size_t  terms )

static

Definition at line 160 of file expr.cpp.

Referenced by purify::circuit_1bit(), purify::circuit_2bit(), purify::circuit_3bit(), purify::circuit_combine(), purify::circuit_ec_add(), and purify::circuit_ec_add_x().

subtract()

ExprBuilder & purify::ExprBuilder::subtract

(

const Expr &

expr

)

Definition at line 199 of file expr.cpp.

References purify::Expr::constant(), purify::FieldElement::is_zero(), purify::Expr::linear(), and purify::FieldElement::negate().

Referenced by add_scaled(), purify::circuit_combine(), purify::circuit_ec_add(), and purify::circuit_ec_add_x().

---

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

• include/purify/expr.hpp
• src/protocol/expr.cpp