Grouping: r()

Sometimes we want to repeat several edit descriptors rather than a single one. In this case, you can group several edit descriptors together using (). This grouping descriptor has the following general forms:

r() and ()

The meaning of r() and () are:

For the form of r(....), the edit descriptors within () repeat r times. For example,
```
(1X, 3(I5, F5.2), A)
```
is equivalent to the following:
```
(1X, I5, F5.2, I5, F5.2, I5, F5.2, A)
```
More precisely, the edit descriptors within (), I5 and F5.2, are repeated three times (i.e., r = 3).
Grouping can also be nested. Suppose we have the following
```
(1X, 3(I5, 2(I4, A3)), A)
```
Then, we can expand 3(...) into the following:
```
(1X, I5, 2(I4, A3), I5, 2(I4, A3), I5, 2(I4, A3), A)
```
After expanding all 2(...)'s, we have the final equivalent format:
```
(1X, I5, I4, A3, I4, A3, I5, I4, A3, I4, A3, I5, I4, A3, I4, A3, A)
```
The form of (...) is equivalent to 1(....). That is, the edit descriptors within (...) are repeated once. This seems redundant. But, as will be discussed in Scanning a Format: III, the parenthesis in grouping plays a very special role.
Please continue with programming examples. If you are not familiar with format scanning, please click here for the simplest rules, followed by here for a subtle but important (to latter topics) extension.