# AttrOperator.java

    package io.github.js0ny.ilp_coursework.util;

    public enum AttrOperator {
        EQ("="),
        NE("!="),
        GT(">"),
        LT("<");

        private final String symbol;

        AttrOperator(String symbol) {
            this.symbol = symbol;
        }

        public static AttrOperator fromString(String symbol) {
            for (AttrOperator op : AttrOperator.values()) {
                if (op.symbol.equals(symbol)) {
                    return op;
                }
            }
            throw new IllegalArgumentException("Unknown operator: " + symbol);
        }
    }