Upgrade Effect to 4.0.0-rc.109

[SandroMaglione]

Summary

• Upgrade the exact Effect peer dependency and companion Effect packages to 4.0.0-rc.109 across the library and examples.
• Remove the consumer-only SchemaAST.Sentinel compatibility declaration that the new RC no longer requires.

Changeset

• Added or updated for a library or package-metadata change
• Not required because this PR does not change src/ or package.json

A minor changeset records the exact peer dependency upgrade.

Validation

• pnpm check
• Relevant example checks, when examples changed
• Automated type-performance measurement passed or was not required
• Automated runtime- and memory-performance measurement passed or was not required

Local smoke checks also completed: pnpm perf:types and pnpm perf:runtime. The automated comparison found no type-instantiation change and no large, noise-adjusted runtime or heap regressions.

[github-actions]

Type performance

Measured with TypeScript 6.0.3 and skipLibCheck=true.

Scenario	Base	PR	Difference
Effect only	55	55	0 (0.0%)
Import effect-machine	55	55	0 (0.0%)
Machine.defineStates (3 states)	3,039	3,039	0 (0.0%)
Machine.make (3 states, 2 events)	13,199	13,199	0 (0.0%)
machine.handle (3 states, 2 transitions)	30,443	30,443	0 (0.0%)
Machine.invoke (state-dependent Effect)	70,236	70,236	0 (0.0%)
machine.handle (depth 24)	188,212	188,212	0 (0.0%)
machine.handle (wide depth 16)	220,710	220,710	0 (0.0%)
machine.handle (parallel/history/choice)	128,069	128,069	0 (0.0%)
machine.handle (4 successive calls)	135,838	135,838	0 (0.0%)
machine exact input/output/error/services	109,952	109,952	0 (0.0%)
execution adapter readiness	121,683	121,683	0 (0.0%)

Marginal instantiations are measured against the matching setup without that API call:

Scenario	Base	PR	Difference
Import effect-machine	0	0	0
Machine.defineStates (3 states)	2,984	2,984	0 (0.0%)
Machine.make (3 states, 2 events)	10,152	10,152	0 (0.0%)
machine.handle (3 states, 2 transitions)	17,244	17,244	0 (0.0%)
Machine.invoke (state-dependent Effect)	59,203	59,203	0 (0.0%)
machine.handle (depth 24)	168,143	168,143	0 (0.0%)
machine.handle (wide depth 16)	201,702	201,702	0 (0.0%)
machine.handle (parallel/history/choice)	102,415	102,415	0 (0.0%)
machine.handle (4 successive calls)	114,587	114,587	0 (0.0%)
machine exact input/output/error/services	93,421	93,421	0 (0.0%)
execution adapter readiness	87,555	87,555	0 (0.0%)

Check times (informational)

Scenario	Base	PR
Effect only	0.03s	0.03s
Import effect-machine	0.03s	0.03s
Machine.defineStates (3 states)	0.11s	0.11s
Machine.make (3 states, 2 events)	0.18s	0.19s
machine.handle (3 states, 2 transitions)	0.27s	0.28s
Machine.invoke (state-dependent Effect)	0.41s	0.41s
machine.handle (depth 24)	0.74s	0.72s
machine.handle (wide depth 16)	0.78s	0.77s
machine.handle (parallel/history/choice)	0.59s	0.59s
machine.handle (4 successive calls)	0.60s	0.61s
machine exact input/output/error/services	0.53s	0.53s
execution adapter readiness	0.54s	0.54s

Type instantiations are the comparison metric. Check time varies with runner load and is informational only.

[github-actions]

Runtime performance

Median of 5 independent benchmark processes on AMD EPYC 7763 64-Core Processor with Node v24.19.0.

Pull request baseline

Scenario	Effect Machine
Plan counter transitions	121,577 transitions/s
Drain burst with terminal fence	371,611 increments/s
Drain burst with a change observer	346,434 increments/s
Lookup and send to one child	309,106 increments/s
Start and stop a machine	149,858 machines/s
Start and stop a parent with one child	30,236 families/s
Plan transitions through a compound state	107,948 transitions/s
Plan transitions through parallel regions	85,692 transitions/s
Drain burst through a compound state	365,028 events/s
Drain burst through two parallel regions	337,676 events/s
Drain a compound-state burst with a change observer	337,174 events/s

Process runtime reference points

Scenario	Effect Machine
Start and stop a raw generic process	14,973 processes/s
Start and stop a raw compiled process	61,084 processes/s

Memory profile	Effect Machine
Idle machine	1.8 KiB
Raw generic managed process	13.9 KiB
Raw compiled process	3.1 KiB
Two independent idle machines	3.4 KiB
Idle parent with one child	5.5 KiB
Parent with observed child registry	9.7 KiB
Parent with observed invoked child snapshots	6.0 KiB

Effect Machine change from base

Metric	Base	Base variability	PR	PR variability	Difference
Plan counter transitions	121,491 transitions/s	1.1% MAD	121,577 transitions/s	1.1% MAD	+0.1%
Drain burst with terminal fence	374,421 increments/s	1.6% MAD	371,611 increments/s	1.8% MAD	-0.8%
Drain burst with a change observer	351,163 increments/s	0.4% MAD	346,434 increments/s	0.9% MAD	-1.3%
Lookup and send to one child	306,986 increments/s	0.2% MAD	309,106 increments/s	2.0% MAD	+0.7%
Start and stop a machine	146,135 machines/s	1.0% MAD	149,858 machines/s	0.6% MAD	+2.5%
Start and stop a parent with one child	28,939 families/s	1.3% MAD	30,236 families/s	2.7% MAD	+4.5%
Plan transitions through a compound state	109,354 transitions/s	1.2% MAD	107,948 transitions/s	3.1% MAD	-1.3%
Plan transitions through parallel regions	84,982 transitions/s	0.3% MAD	85,692 transitions/s	1.6% MAD	+0.8%
Drain burst through a compound state	367,880 events/s	0.6% MAD	365,028 events/s	2.3% MAD	-0.8%
Drain burst through two parallel regions	340,744 events/s	0.4% MAD	337,676 events/s	2.5% MAD	-0.9%
Drain a compound-state burst with a change observer	342,366 events/s	0.2% MAD	337,174 events/s	1.7% MAD	-1.5%
Idle machine heap per unit	1.8 KiB	0.1% MAD	1.8 KiB	0.0% MAD	-0.0%
Raw generic managed process heap per unit	13.9 KiB	0.0% MAD	13.9 KiB	0.0% MAD	-0.0%
Raw compiled process heap per unit	3.1 KiB	0.1% MAD	3.1 KiB	0.1% MAD	+0.0%
Two independent idle machines heap per unit	3.4 KiB	0.0% MAD	3.4 KiB	0.0% MAD	+0.0%
Idle parent with one child heap per unit	5.5 KiB	0.0% MAD	5.5 KiB	0.0% MAD	+0.0%
Parent with observed child registry heap per unit	9.7 KiB	0.0% MAD	9.7 KiB	0.0% MAD	-0.0%
Parent with observed invoked child snapshots heap per unit	6.0 KiB	0.1% MAD	6.0 KiB	0.0% MAD	-0.5%

Process runtime reference change from base

Metric	Base	Base variability	PR	PR variability	Difference
Start and stop a raw generic process	14,938 processes/s	1.7% MAD	14,973 processes/s	1.5% MAD	+0.2%
Start and stop a raw compiled process	61,350 processes/s	0.5% MAD	61,084 processes/s	1.4% MAD	-0.4%

Regression guard

No large, noise-adjusted throughput or heap regressions detected.

Versions and interpretation

• Effect Machine: 0.12.0

Higher throughput is better; lower heap is better. Variability is the median absolute deviation across independent processes, relative to their median. Small differences on shared GitHub-hosted hardware remain informational; the required guard rejects only large changes beyond the measured noise allowance.