github.com/consensys/gnark@v0.11.0/frontend/variable.go (about)

     1  /*
     2  Copyright © 2020 ConsenSys
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package frontend
    18  
    19  import (
    20  	"github.com/consensys/gnark/frontend/internal/expr"
    21  )
    22  
    23  // Variable represents a variable in the circuit. Any integer type (e.g. int, *big.Int, fr.Element)
    24  // can be assigned to it. It is also allowed to set a base-10 encoded string representing an integer value.
    25  // The only purpose of putting this definition here is to avoid the import cycles (cs/plonk <-> frontend) and (cs/r1cs <-> frontend)
    26  type Variable interface{}
    27  
    28  // IsCanonical returns true if the Variable has been normalized in a (internal) LinearExpression
    29  // by one of the constraint system builder. In other words, if the Variable is a circuit input OR
    30  // returned by the API.
    31  func IsCanonical(v Variable) bool {
    32  	switch v.(type) {
    33  	case expr.LinearExpression, *expr.LinearExpression, expr.Term, *expr.Term:
    34  		return true
    35  	}
    36  	return false
    37  }