Here is a snippet of a code I am writing in Q#(QDK by Microsoft) trying to program the HHL algorithm.

`  operation PrepareBState(register: Qubit[], coefficients: Double[]): Unit is Adj + Ctl {
        let n = Length(register);
        if (n != Length(coefficients)) {
            fail "The length of coefficients array must match the number of qubits.";
        }

        // Normalize the coefficients
        let norm = Sqrt(Sum([x * x | x in coefficients]));

        mutable normalizedCoefficients = coefficients;
        for (i in 0 .. Length(coefficients) - 1) {
            set normalizedCoefficients w/= i <- coefficients[i] / norm;
        }

        // Prepare |b⟩ state using the normalized coefficients
        for (i in 0 .. n - 1) {
            Ry(2.0 * ArcCos(normalizedCoefficients[i]), register[i]);
        }
    }`

However each time I get the following errors “syntax error: expected ), found keyword in(Qsc.Parse.Token)”, “syntax error: expected }, found keyword for(Qsc.Parse.Token)” and “syntax error: expected EOF, found }(Qsc.Parse.Token)”

I wonder if anyone knows what those errors mean or how to fix them

I tried using list comprehension syntax in Q# to compute the sum of squares of the coefficients. I thought that this should resolve the syntax error on the normalization line. But alas, it does not.