Why the channel is written
A written channel is a channel a reader lists. A channel in a name is a channel that cannot be listed.
The failure at this step
A message with no receiver. The channel is the answer, and the channel names the part.
Parts talking as a named channel
The parts of an extension do not share a body. They share a channel, and a channel is a name that makes a message findable.
What you will see
refuse names ghost. Nothing is silent.
About 1 min of reading
Try It
Name a sender and a receiver
1
Write the channel
printf 'reader\nwriter\nreport\n' > /tmp/c.txt; wc -l < /tmp/c.txt
Before you run it, say out loud what it will print. Then open the answer.
What it prints
3. Three parts is the channel, which is written.
2
Write a message
printf 'from=reader to=writer count=12\n' > /tmp/m.txt; cat /tmp/m.txt
Before you run it, say out loud what it will print. Then open the answer.
What it prints
One line with a sender and a receiver. Named is traceable.
3
Refuse no receiver
printf 'to=ghost\n' | grep -c -f -x /tmp/c.txt /dev/stdin | awk '{print ($1==0) ? "refuse names ghost" : "ok"}'
Before you run it, say out loud what it will print. Then open the answer.
What it prints
refuse names ghost. Nothing is silent.
Data Flow
A part to an answered message
1
The channel is written as a list of parts
↓
2
A message is written with a sender
↓
3
The receiver is named in the channel
↓
4
No receiver refuses with the name
Why this works
Examples
The message has a sender
The sender is a name. A named sender is a message that can be traced back to a part.
The channel is one direction
One direction is one order. An order is what makes a message that arrived different from one that did not.
A message is answered or refused
Nothing is silent. Silence is what makes a part that never ran look like a part that ran.
Words this lesson uses
Each one is defined here on this site. Open the entry for the full definition and the other words it points at.
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