snarkjs/src/r1cs_print.js

zkSNARKs implementation in JavaScript

/*
    Copyright 2018 0KIMS association.

    This file is part of snarkJS.

    snarkJS is a free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    snarkJS is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
    License for more details.

    You should have received a copy of the GNU General Public License
    along with snarkJS. If not, see <https://www.gnu.org/licenses/>.
*/

export default function r1csPrint(r1cs, syms, logger) {
    for (let i=0; i<r1cs.constraints.length; i++) {
        printCostraint(r1cs.constraints[i]);
    }
    function printCostraint(c) {
        const lc2str = (lc) => {
            let S = "";
            const keys = Object.keys(lc);
            keys.forEach( (k) => {
                let name = syms.varIdx2Name[k];
                if (name == "one") name = "1";

                let vs = r1cs.curve.Fr.toString(lc[k]);
                if (vs == "1") vs = "";  // Do not show ones
                if (vs == "-1") vs = "-";  // Do not show ones
                if ((S!="")&&(vs[0]!="-")) vs = "+"+vs;
                if (S!="") vs = " "+vs;
                S= S + vs   + name;
            });
            return S;
        };
        const S = `[ ${lc2str(c[0])} ] * [ ${lc2str(c[1])} ] - [ ${lc2str(c[2])} ] = 0`;
        if (logger) logger.info(S);
    }

}