Add consumer machine type extractors

[SandroMaglione]

Summary

• add Machine.Value and Machine.SnapshotAt for definition- or machine-bound state extraction
• allow Machine.Snapshot to extract from either typeof States or typeof machine
• make Machine.Machine.Input return decoded startup input, with InputSchema retaining schema access
• document canonical consumer annotations and rejected transition-context extraction patterns

Changeset

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

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 validation also confirmed unchanged Pokémon type instantiations and negligible Playground impact from adopting the new public extractors.

[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.states (3 states)	3,039	3,039	0 (0.0%)
Machine.make (3 states, 2 events)	10,759	10,759	0 (0.0%)
machine.handle (3 states, 2 transitions)	28,192	28,192	0 (0.0%)
fluent transition (10 named branches)	106,006	106,006	0 (0.0%)
fluent invocation (state-dependent Effect)	92,756	92,756	0 (0.0%)
machine.handle (depth 24)	192,588	192,588	0 (0.0%)
machine.handle (wide depth 16)	220,950	220,950	0 (0.0%)
machine.handle (parallel/history/choice)	128,389	128,389	0 (0.0%)
machine definition (3 independent implementations)	127,342	127,342	0 (0.0%)
machine exact input/output/error/services	113,853	113,924	+71 (+0.1%)
execution adapter readiness	118,896	118,896	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.states (3 states)	2,984	2,984	0 (0.0%)
Machine.make (3 states, 2 events)	7,712	7,712	0 (0.0%)
machine.handle (3 states, 2 transitions)	17,433	17,433	0 (0.0%)
fluent transition (10 named branches)	95,757	95,757	0 (0.0%)
fluent invocation (state-dependent Effect)	83,491	83,491	0 (0.0%)
machine.handle (depth 24)	171,892	171,892	0 (0.0%)
machine.handle (wide depth 16)	201,461	201,461	0 (0.0%)
machine.handle (parallel/history/choice)	108,126	108,126	0 (0.0%)
machine definition (3 independent implementations)	111,373	111,373	0 (0.0%)
machine exact input/output/error/services	99,342	99,413	+71 (+0.1%)
execution adapter readiness	89,084	89,084	0 (0.0%)

Check times (informational)

Scenario	Base	PR
Effect only	0.03s	0.03s
Import effect-machine	0.03s	0.03s
Machine.states (3 states)	0.11s	0.11s
Machine.make (3 states, 2 events)	0.17s	0.17s
machine.handle (3 states, 2 transitions)	0.27s	0.26s
fluent transition (10 named branches)	0.52s	0.51s
fluent invocation (state-dependent Effect)	0.53s	0.50s
machine.handle (depth 24)	0.82s	0.82s
machine.handle (wide depth 16)	0.85s	0.83s
machine.handle (parallel/history/choice)	0.65s	0.64s
machine definition (3 independent implementations)	0.67s	0.64s
machine exact input/output/error/services	0.58s	0.59s
execution adapter readiness	0.60s	0.58s

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 Intel(R) Xeon(R) 6973P-C with Node v24.19.0.

Pull request baseline

Scenario	Effect Machine
Plan counter transitions	175,799 transitions/s
Drain burst with terminal fence	578,617 increments/s
Drain burst with a change observer	537,287 increments/s
Lookup and send to one child	489,963 increments/s
Start and stop a machine	225,225 machines/s
Start and stop a parent with one child	65,041 families/s
Plan transitions through a compound state	156,042 transitions/s
Plan transitions through parallel regions	125,171 transitions/s
Drain burst through a compound state	466,969 events/s
Drain burst through two parallel regions	462,513 events/s
Drain a compound-state burst with a change observer	437,855 events/s

Process runtime reference points

Scenario	Effect Machine
Start and stop a raw generic process	44,707 processes/s
Start and stop a raw compiled process	104,210 processes/s

Memory profile	Effect Machine
Idle machine	1.8 KiB
Raw generic managed process	13.9 KiB
Raw compiled process	3.2 KiB
Two independent idle machines	3.4 KiB
Idle parent with one child	5.8 KiB
Parent with observed child registry	10.0 KiB
Parent with observed invoked child snapshots	6.4 KiB

Effect Machine change from base

Metric	Base	Base variability	PR	PR variability	Difference
Plan counter transitions	186,279 transitions/s	0.6% MAD	175,799 transitions/s	2.7% MAD	-5.6%
Drain burst with terminal fence	602,159 increments/s	5.1% MAD	578,617 increments/s	3.1% MAD	-3.9%
Drain burst with a change observer	527,535 increments/s	4.3% MAD	537,287 increments/s	1.6% MAD	+1.8%
Lookup and send to one child	499,353 increments/s	1.8% MAD	489,963 increments/s	0.2% MAD	-1.9%
Start and stop a machine	221,141 machines/s	2.6% MAD	225,225 machines/s	2.5% MAD	+1.8%
Start and stop a parent with one child	65,240 families/s	1.5% MAD	65,041 families/s	3.1% MAD	-0.3%
Plan transitions through a compound state	146,791 transitions/s	2.4% MAD	156,042 transitions/s	2.0% MAD	+6.3%
Plan transitions through parallel regions	121,094 transitions/s	3.7% MAD	125,171 transitions/s	1.5% MAD	+3.4%
Drain burst through a compound state	429,361 events/s	5.5% MAD	466,969 events/s	1.8% MAD	+8.8%
Drain burst through two parallel regions	445,634 events/s	2.0% MAD	462,513 events/s	3.2% MAD	+3.8%
Drain a compound-state burst with a change observer	435,140 events/s	2.4% MAD	437,855 events/s	1.3% MAD	+0.6%
Idle machine heap per unit	1.8 KiB	0.1% MAD	1.8 KiB	0.1% MAD	-0.1%
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	3.2 KiB	0.3% MAD	3.2 KiB	0.0% MAD	-0.0%
Two independent idle machines heap per unit	3.4 KiB	0.1% MAD	3.4 KiB	0.0% MAD	-0.1%
Idle parent with one child heap per unit	5.8 KiB	0.0% MAD	5.8 KiB	0.0% MAD	0.0%
Parent with observed child registry heap per unit	10.0 KiB	0.0% MAD	10.0 KiB	0.0% MAD	+0.0%
Parent with observed invoked child snapshots heap per unit	6.4 KiB	0.0% MAD	6.4 KiB	0.0% MAD	+0.0%

Process runtime reference change from base

Metric	Base	Base variability	PR	PR variability	Difference
Start and stop a raw generic process	44,142 processes/s	6.0% MAD	44,707 processes/s	2.2% MAD	+1.3%
Start and stop a raw compiled process	101,482 processes/s	5.2% MAD	104,210 processes/s	0.8% MAD	+2.7%

Regression guard

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

Versions and interpretation

• Effect Machine: 0.17.0

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.