Requiring a reset to load files into file input communicators might be awkward

[btzy]

Currently, after selecting a file for the file input communicator, a reset is required to start reading from the selected file.

This is because:

• Circuits should be allowed to assume that once the file communicator reports an EOF, there cannot be any more data from the file communicator;
• So the file communicator should not be allowed to load a new file while the circuit is in progress.

The most straightforward way to satisfy these requirements is to only load the selected files on reset, which is the current implementation.

Some possible alternatives that could be considered:

• Only allow loading a new file if the circuit has not received an EOF. (Issue: This behaviour might be unexpected by the user.)
• Have some way to signal the circuit about a new file being loaded. (Issue: More complex protocol means that the circuit has to be more complicated.)

[btzy]

This has been closed by a9c9b194b97ad7d2ca5e91ec7bffcce9f0c2d399.