Appendix C — Sources
This appendix contains only public, reader-verifiable references. Claims should distinguish official mechanism documentation, public package documentation, public source observations, public test assertions, and editorial proposals.
C.1 S7 mechanism documentation
- S7 package site and vignettes
- Classes and objects
- Generics and methods
S7::new_property()reference- S7 repository and public tests
- Public S4 property-type discussion
Official documentation is the authority for supported mechanisms. Version-sensitive runtime claims should also identify released R and S7 versions used by a reproducible probe.
C.2 Principal public exhibits
C.2.1 rtemis
- Repository and source
PropertySpecand property declarations- Immutable
PropertySpecsource at revisionf60ac02
Public source observation. The linked implementation supports the chapter’s claims about constraints as data, separate tuning intent, defaults, conditional applicability, contextual data bounds, and multiple consumers. Whether every generated projection remains aligned is an obligation proposed by the chapter, not a fact inferred from one implementation.
C.2.2 deputy
- Repository and README
- Package site
- Getting started
- Permissions
- Runtime integration
- Immutable repository snapshot at revision
2a4bda5
Public package documentation and source observation. These sources support the distinction among declarative tools and policies, host-enforced permissions, live agent execution, streaming, and completed run results. The chapter’s ownership vocabulary is an editorial interpretation of those public mechanisms.
C.2.3 sqlr
- Repository and README
- Immutable README at revision
8325581 - Public generic definitions at revision
8325581
Public documentation and source observation. The README and generic definitions support the claims about a semantic schema representation shared by rendering, reflection, equality, and diffing; dialect objects; refusal of a generic fallback; dependency-aware rendering; and bounded reflection. Calling this an “earned IR” is the chapter’s editorial evaluation.
C.3 Focused contrasts
C.3.1 S7schema
Official package documentation. The package page and manual support the claims that YAML content is validated against JSON Schema through AJV/V8 and that S7 supplies surrounding configuration and extension machinery. The authority comparison with stacbuildr is editorial synthesis.
C.3.2 resultr
Public source observation. The implementation supports the claims about Success and Failure, short-circuiting and_then(), and the wrap_in_result() adapter between conditions and values. The recommendation to choose one deliberate boundary is editorial.
C.3.3 stacbuildr
Public package documentation and source observation. These sources support the claims about STAC document classes, validation against published schemas, native geospatial boundary constructors, and tabular or spatial projections. The claim that the native layer and external schema have different authority is editorial synthesis.
C.4 Additional exhibits used in prose
C.4.1 quickr
- Repository
- Published source mirror
- Immutable
quick.Rsource at revisionedd4037 - Immutable repository snapshot at revision
edd4037
Public source observation. The source supports the bounded claim that quickr compiles R toward Fortran and passes structured, typed artifacts such as FortranSubroutine through compilation. The broader lesson that a typed IR must be earned by analysis and translation is editorial.
C.4.2 typedjson
Public package documentation. The README supports the claims that ordinary values remain readable JSON, annotations are introduced for distinctions JSON cannot preserve, and the intended law is an R-value round trip. “Minimum metadata” is the chapter’s summary of that documented design.
C.4.3 s7contract
Official package documentation and public source observation. These sources support the claims about structural interfaces, explicit traits, runtime argument and return contracts, and generative laws with shrinking. The limits of sampled laws are an editorial caution, not a package guarantee.
C.4.4 optimizers7 and parameters7
- optimizers7 repository
- parameters7 repository
- Immutable optimizers7 README at revision
c50e414 - Immutable parameters7 README at revision
21076ad
Public package documentation. The linked READMEs support the claims that stopping rules are modeled separately and compositionally, and that constrained parameters expose reusable maps, inverses, and derivatives. The decision threshold for promoting policy to an object is editorial.
C.5 Other public package references
- ellmer: documentation,
Chat,Turn, andModel - ragnar:
MarkdownDocumentandmarkdown_chunk() - s7x: package site and enum note
- rapid
- tooey
- structr
- reflect/datarr: repository and S7 source
Ellmer appears in the deputy discussion only to identify the public chat abstraction with which deputy composes; the linked official documentation is the source for that identification. The remaining packages are retained as descriptive public references used elsewhere in the book. Inclusion is not a claim about popularity, maturity, or comparative quality.
C.6 Public theory and engineering references
- Alexis King, “Parse, don’t validate”
- Robert Harper, “Boolean blindness”
- Gary Bernhardt, “Boundaries”
- Yaron Minsky, “Effective ML”
- Philip Wadler, “The expression problem”
- Rich Hickey, “The Value of Values”
- LANGSEC resources
- Hadley Wickham, Advanced R, “Translating R code”
- Hadley Wickham, Tidy design principles
- S7 0.2.0 release notes, including native-serialization limitations
- R serialization reference
- NVD, CVE-2024-27322 on untrusted R deserialization
- CERT Coordination Center, VU#238194
- BiocGenerics
updateObject()reference - future guidance for package developers and non-exportable objects
Conceptual background also includes Bertrand Meyer’s Object-Oriented Software Construction; Eric Evans’s Domain-Driven Design; Gamma, Helm, Johnson, and Vlissides’s Design Patterns; Scott Wlaschin’s Domain Modeling Made Functional; and David Parnas’s “On the Criteria To Be Used in Decomposing Systems into Modules.”
C.7 Evidence labels
- Official mechanism: documented by S7 or another authoritative public specification.
- Public source observation: visible in a linked public repository; behavior may change. Version-sensitive observations should use an immutable revision link.
- Public test assertion: encoded in a linked package test suite.
- Released-version probe: reproducible execution naming R, S7, and package versions.
- Editorial proposal: guidance offered for evaluation, not a claim that a package implements it.
A source comment, README statement, or single implementation can motivate a question. It should not become a universal claim without corroborating evidence.