private boolean isHashCompatible(DataType type) {
        if (type.equals(DataType.INT)) return true;
        if (type.equals(DataType.LONG)) return true;
        return false;
    }
Hashes a string value to a long or int (by type inference on the target value).

@author bratseth
indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/HashExpression.java