Message Bus Live Coding Exercise - Revision history

Jwgranville: /* Phase 3: Explore shell command data by hand */

2026-06-16T16:50:09Z

Phase 3: Explore shell command data by hand

← Older revision		Revision as of 16:50, 16 June 2026
Line 656:		Line 656:
	The dictionary contains the information, but it does not document the shape of the event. A typo is discovered only when the field is used. A named event class makes the processor code easier to read and easier to explain.		The dictionary contains the information, but it does not document the shape of the event. A typo is discovered only when the field is used. A named event class makes the processor code easier to read and easier to explain.

	Positional encoding like tuples and CSV-like records also suffer from this innate limitation. They are inherently detached from the structural contract of the record type; they describe ~~the~~ data they carry, not any particular schema or type contract to which it belongs.		Positional encoding like tuples and CSV-like records also suffer from this innate limitation. They are inherently detached from the structural contract of the record type; they describe only whatever data they carry, not any particular schema or type contract to which the record itself belongs.

	== Phase 4: Persist the event record classes ==		== Phase 4: Persist the event record classes ==

Jwgranville: /* Phase 3: Explore shell command data by hand */

2026-06-16T16:48:57Z

Phase 3: Explore shell command data by hand

← Older revision		Revision as of 16:48, 16 June 2026
Line 72:		Line 72:
	** Build the capture history helper.		** Build the capture history helper.

	Estimated time: 1.5-3 hours (1-2 hours work, 0.5-1 hours setup)		Estimated time: 1-3 hours (1-2 hours work, 0.5-1 hours setup)

	; Session 2 - Shell commands and milestones		; Session 2 - Shell commands and milestones
Line 655:		Line 655:

	The dictionary contains the information, but it does not document the shape of the event. A typo is discovered only when the field is used. A named event class makes the processor code easier to read and easier to explain.		The dictionary contains the information, but it does not document the shape of the event. A typo is discovered only when the field is used. A named event class makes the processor code easier to read and easier to explain.

			Positional encoding like tuples and CSV-like records also suffer from this innate limitation. They are inherently detached from the structural contract of the record type; they describe the data they carry, not any particular schema or type contract to which it belongs.

	== Phase 4: Persist the event record classes ==		== Phase 4: Persist the event record classes ==

Jwgranville: /* Suggested group session flow */

2026-06-16T15:04:16Z

Suggested group session flow

← Older revision		Revision as of 15:04, 16 June 2026
Line 72:		Line 72:
	** Build the capture history helper.		** Build the capture history helper.

	Estimated time: 1-3 hours (1-2 hours work, 0.5-1 hours setup)		Estimated time: 1.5-3 hours (1-2 hours work, 0.5-1 hours setup)

	; Session 2 - Shell commands and milestones		; Session 2 - Shell commands and milestones

Jwgranville: /* Phase 14: Add a randomized processor scheduler */

2026-06-16T05:31:58Z

Phase 14: Add a randomized processor scheduler

← Older revision		Revision as of 05:31, 16 June 2026
Line 2,212:		Line 2,212:
	* The scheduler varies which processor gets a chance to run first.		* The scheduler varies which processor gets a chance to run first.
	* This simulates uncertainty from processing time, scheduling priority, startup timing, or transmission delay.		* This simulates uncertainty from processing time, scheduling priority, startup timing, or transmission delay.
	* The graph example should converge to the same final path facts even when processor scheduling, and ~~hence~~ the order of intermediate derived processor events, differs.		* The graph example should converge to the same final path facts even when processor scheduling - and the order of intermediate derived processor events - differs.

	; File edit		; File edit

Jwgranville: /* Phase 9: Introduce graph events */

2026-06-16T05:14:54Z

Phase 9: Introduce graph events

← Older revision		Revision as of 05:14, 16 June 2026
Line 1,431:		Line 1,431:
	; Goal		; Goal

	Switch to a small graph problem that can demonstrate feedback loops ~~safely~~.		Switch to a small graph problem that can demonstrate safe feedback loops in an illustratable form.

	; Discussion points		; Discussion points

Jwgranville: /* Phase 3: Explore shell command data by hand */

2026-06-16T04:56:50Z

Phase 3: Explore shell command data by hand

← Older revision		Revision as of 04:56, 16 June 2026
Line 74:		Line 74:
	Estimated time: 1-3 hours (1-2 hours work, 0.5-1 hours setup)		Estimated time: 1-3 hours (1-2 hours work, 0.5-1 hours setup)

	; Session 2 - Shell ~~command~~ and ~~regex~~ milestones		; Session 2 - Shell commands and milestones

	* '''Phase 3:'''		* '''Phase 3:'''
Line 81:		Line 81:
	** Replace it with <code>ShellCommandEvent</code>.		** Replace it with <code>ShellCommandEvent</code>.
	* '''Phase 5:'''		* '''Phase 5:'''
	** Manually evaluate ~~regex~~ milestone expressions.		** Manually evaluate milestone expressions.
	* '''Phase 6:'''		* '''Phase 6:'''
	** Implement <code>RegexMilestoneProcessor</code>.		** Implement <code>RegexMilestoneProcessor</code>.
Line 92:		Line 92:
	* '''Phase 7:'''		* '''Phase 7:'''
	** Create raw TTY read, write, and line events.		** Create raw TTY read, write, and line events.
	** Show why ~~regex~~ milestones need reconstructed shell command events.		** Show why milestones need reconstructed shell command events.
	* '''Phase 8:'''		* '''Phase 8:'''
	** Implement keystroke timing.		** Implement keystroke timing.
Line 596:		Line 596:
	; Goal		; Goal

	Identify the high-level event shape needed by a ~~regex~~ milestone processor.		Identify the high-level event shape needed by a milestone processor.

	; Discussion points		; Discussion points
Line 622:		Line 622:
	</pre>		</pre>

	Inspect the fields used by ~~regex~~ milestone checks:		Inspect the fields used by milestone checks:

	<pre lang="python">		<pre lang="python">
Line 660:		Line 660:
	; Goal		; Goal

	Create reusable payload classes for the TTY, shell command, and ~~regex~~ milestone examples.		Create reusable payload classes for the TTY, shell command, and milestone examples.

	; File edit		; File edit
Line 797:		Line 797:
	The event shape is now explicit. Other code can depend on a named <code>ShellCommandEvent</code> instead of assuming that a loose dictionary has the expected fields.		The event shape is now explicit. Other code can depend on a named <code>ShellCommandEvent</code> instead of assuming that a loose dictionary has the expected fields.

	== Phase 5: Evaluate ~~regex~~ milestones manually ==		== Phase 5: Evaluate milestones manually ==

	; Goal		; Goal
Line 805:		Line 805:
	; Discussion points		; Discussion points

	* A ~~regex~~ milestone expression names one check against one shell command field.		* A milestone expression names one check against one shell command field.
	* The field may be command input, command output, working directory, or host context.		* The field may be command input, command output, working directory, or host context.
	* The result records whether the expression matched and, when available, the matched text.		* The result records whether the expression matched and, when available, the matched text.
Line 1,163:		Line 1,163:
	* TTY reads, TTY writes, and line-discipline lines are lower-level observations.		* TTY reads, TTY writes, and line-discipline lines are lower-level observations.
	* A shell command event is reconstructed by correlating those observations.		* A shell command event is reconstructed by correlating those observations.
	* Keeping reconstruction separate prevents the ~~regex~~ milestone processor from becoming a large TTY parser.		* Keeping reconstruction separate prevents the milestone processor from becoming a large TTY parser.

	; Interpreter exploration		; Interpreter exploration
Line 2,557:		Line 2,557:
	; Goal		; Goal

	Connect the TTY examples back to the shell command event shape used by ~~regex~~ milestones.		Connect the TTY examples back to the shell command event shape used by milestones.

	; Discussion points		; Discussion points

	* <code>ShellCommandEvent</code> is the high-level event consumed by the ~~regex~~ milestone processor.		* <code>ShellCommandEvent</code> is the high-level event consumed by the milestone processor.
	* <code>TTYReadEvent</code>, <code>TTYWriteEvent</code>, and <code>LineDisciplineEvent</code> are lower-level observations.		* <code>TTYReadEvent</code>, <code>TTYWriteEvent</code>, and <code>LineDisciplineEvent</code> are lower-level observations.
	* A reconstructor can subscribe to line-discipline events and query recent related observations.		* A reconstructor can subscribe to line-discipline events and query recent related observations.
Line 2,576:		Line 2,576:
	</pre>		</pre>

	This is an appropriate follow-up exercise after the team understands both ~~regex~~ milestone processing and history queries.		This is an appropriate follow-up exercise after the team understands both milestone processing and history queries.

	= Related =		= Related =

Jwgranville: /* Create the demonstration package */

2026-06-16T04:30:40Z

Create the demonstration package

← Older revision		Revision as of 04:30, 16 June 2026
Line 54:		Line 54:
	touch demos/event_processors/__init__.py		touch demos/event_processors/__init__.py
	</pre>		</pre>


	== Important note about capture records ==		== Important note about capture records ==

Jwgranville: /* Audience and scope */

2026-06-16T04:30:06Z

Audience and scope

← Older revision		Revision as of 04:30, 16 June 2026
Line 33:		Line 33:
	** Simulate nondeterministic processor scheduling while keeping source input fixed.		** Simulate nondeterministic processor scheduling while keeping source input fixed.

	The shell examples draw from EDURange's institutional knowledge. The graph examples provide a ~~compact computer science~~ model for ~~safe~~ feedback loops.		The shell examples draw from EDURange's institutional knowledge. The graph examples provide a common model problem family for meaningful use of feedback loops.

	== Running the examples ==		== Running the examples ==

Jwgranville: /* Audience and scope */

2026-06-16T04:27:57Z

Audience and scope

← Older revision		Revision as of 04:27, 16 June 2026
Line 16:		Line 16:
	__init__.py		__init__.py
	</pre>		</pre>

			Pre-release copies of <code>mbus</code> and <code>aostore</code> are available on the Discord fileshare channel. Modules may be released under other package names; see also the EDURange GitHub.

	The exercise uses two problem families.		The exercise uses two problem families.

Jwgranville at 04:09, 16 June 2026

2026-06-16T04:09:15Z

← Older revision		Revision as of 04:09, 16 June 2026
Line 2,578:		Line 2,578:
	This is an appropriate follow-up exercise after the team understands both regex milestone processing and history queries.		This is an appropriate follow-up exercise after the team understands both regex milestone processing and history queries.

	== Related ==		= Related =

	=== Top-level topic page ===		== Top-level topic page ==
	[[Message Bus Service]]		[[Message Bus Service]]