Accord.Math.Optimization.LinearConstraint.parseExpression C# (CSharp) Method

        private void parseExpression(IObjectiveFunction function, Expression<Func<bool>> constraint)
        {
            ConstraintType type;

            switch (constraint.Body.NodeType)
            {
                case ExpressionType.Equal:
                    type = ConstraintType.EqualTo; break;

                case ExpressionType.LessThanOrEqual:
                    type = ConstraintType.LesserThanOrEqualTo; break;

                case ExpressionType.GreaterThanOrEqual:
                    type = ConstraintType.GreaterThanOrEqualTo; break;

                default:
                    throw new FormatException("Unexpected expression.");
            }

            BinaryExpression b = constraint.Body as BinaryExpression;
            var terms = new Dictionary<string, double>();
            double value = 0;
            parse(terms, b.Left, ref value);

            ConstantExpression c = b.Right as ConstantExpression;
            value = (double)c.Value - value;

            List<int> indices = new List<int>();
            List<double> scalars = new List<double>();

            foreach (var term in terms)
            {
                indices.Add(function.Variables[term.Key]);
                scalars.Add(term.Value);
            }

            NumberOfVariables = indices.Count;
            VariablesAtIndices = indices.ToArray();
            CombinedAs = scalars.ToArray();
            ShouldBe = type;
            Value = value;
        }