private void consumeList(int dimension) {
            consume('[');
            indexes[dimension] = 0;
            while ( ! atListEnd() ) {
                if (isInnerMostDimension(dimension)) {
                    consumeNumber();
                } else {
                    consumeList(dimension + 1);
                }
                indexes[dimension]++;
                consumeOptional(',');
            }
            consume(']');
        }
Parses unbound tensor short forms - e.g. tensor(x[],y[]):[[1,2,3],[4,5,6]]
vespajlib/src/main/java/com/yahoo/tensor/TensorParser.java