Function assertStringIsValidPauliStrSum

quest/src/core/parser.cpp:396–430

void assertStringIsValidPauliStrSum(string lines, const char* caller) {

    int numPaulis = 0;
    bool nonEmptyLine = false;
    qindex lineIndex = 0;

    // parse each line in-turn
    stringstream stream(lines);

    for (string line; getline(stream, line); lineIndex++) {

        // permit and skip empty lines
        if (isOnlyWhiteSpace(line))
            continue;
        else
            nonEmptyLine = true;
        
        // assert the line is interpretable
        bool validLine = isInterpretablePauliStrSumLine(line);
        validate_parsedPauliStrSumLineIsInterpretable(validLine, line, lineIndex, caller);

        // assert the coeff is parsable (e.g. doesn't exceed valid number range)
        bool validCoeff = isPauliStrSumCoeffWithinQcompRange(line);
        validate_parsedPauliStrSumCoeffWithinQcompRange(validCoeff, line, lineIndex, caller);

        // assert the line has a consistent number of Paulis as previous
        int numLinePaulis = getNumPaulisInLine(line);
        if (!numPaulis)
            numPaulis = numLinePaulis;
        validate_parsedPauliStrSumLineHasConsistentNumPaulis(numPaulis, numLinePaulis, line, lineIndex, caller);
    }

    // ensure we parsed at least 1 Pauli string
    validate_parsedStringIsNotEmpty(nonEmptyLine, caller);
}