5.13.8 Functionality to be Implemented Later This section lists the functionality not yet in Regina, but which is intended to be added later. Most of these are fixes to problems, compatibility modes, etc. [Indirect naming of streams.] Currently, streams are named directly, which is a convenient. However, there are a few problems: for instance, it is difficult to write to a file which name is <stdout>, simply because that is a reserved name. To fix this, an indirect naming scheme will be provided through the STREAM()< built-in function. The functionality will resemble the OPEN() built-in function of ARexx. [Consistence in filehandle swapping.] When a file handle is currently swapped out in order to avoid filling the system file table, very little checking of consistency is currently performed. At least, vital information about the file should be retained, such as the inode and file system for Unix machines retrieval by the fstat() call. When the file is swapped in again, this information must be checked against the file which is reopened. If there is a mismatch, NOTREADY should be raised. Similarly, when reopening a file because of a new access mode is requested, the same checking should be performed. [Files with holes.] Regina will be changed to allow it to generate files with holes for system where this is relevant. Although standard REXX does not allow this, it is a very common programming idiom for certain systems, and should be allowed. It will, however, be controllable through a extension called SparseFiles.