tom_som_cpp_runtime — generic C++ SOM runtime

> Cross-references. > tom_specs_model/doc/som_multiplatform_spec_model.md > is the SOM authority: SOM §9 decides what a runtime must contain, SOM §6 > decides the split between the generic and the typed access path, SOM §11 and > SOM §12 decide the *.md and *.docspecs.yaml formats, and SOM §19 > decides the conformance corpus this port is measured against. > tom_specs_model/doc/som_toolchains.md > decides this language plane's build and verify toolchain. This README says how > to use this package's code; those documents own the model, the formats and > the rules, and nothing here restates them.

Generic TomSpecs object-model runtime (C++). Paths, model, reflection, document, validator, YAML/Markdown codecs, in idiomatic C++17 with RAII; zero external dependencies (C++ standard library only).

Where this fits

TomSpecs specifications are documents with a typed shape: a spec model describes which sections exist, what each may contain and how it serializes. The SOM makes that model usable from nine languages, and each language is a pair — a hand-written runtime (this library) holding everything that is the same everywhere, and a generated tom_som_cpp_v0 facade holding the typed classes for one model version. Without the split, every regeneration would rewrite the document store, the codecs and the validator; with it, the generator emits only what actually changes when the model changes.

This library is a faithful transcription of the C reference, tom_som_c_runtime, which itself ports the Dart reference and the Python/Java/JavaScript/TypeScript/Go/Rust ports — it invents nothing, and "faithful" is a measured claim rather than an intention: every port is validated against the same goldens, byte for byte (SOM §19). Reach for it directly when you drive the generic API by section path; otherwise link the typed facade, which links this in.

Overview

A SOM document is sparse and path-keyed: values live in three stores (content, form fields, list sequences) under the globally-unique section-ID path they belong to, and an absent key means "no value" rather than an empty one. SpecDocument is that store. Everything else in the library is a layer over it — the meta-model (SpecModel, SpecReflection) that makes generic navigation possible without generated classes, the byte-stable YAML and Markdown codecs, the editing and validation tiers, and the Phase-4 CodeSpecs extractor.

Where the C port shipped its own growable buffer / list / byte-sorted map, this port uses std::string, std::vector, and std::map<std::string, …> (which iterates in byte order for std::string keys, matching the C SomMap's strcmp ordering — the byte-stable codecs rely on it).

It holds no document values of its own and contains no generated typed classes — those belong to the per-language tom_som_<lang>_v0 projects. include/tom_som_cpp_runtime.hpp is the umbrella header; the per-module headers may also be included directly.

Installation

C++ has no universal package registry, so the library is distributed as a library + headers + pkg-config file, or as a source tarball:

make install PREFIX=/usr/local   # headers, static/shared libs, and the .pc file
make dist                        # build/tom_som_cpp_runtime-<version>.tar.gz

make install honours DESTDIR for staged / packaged installs and lays down the versioned .so soname symlinks. The pkg-config Version tracks the TomSpecs model version, and tom_som_cpp_v0 pins the same one — upgrade both together (SOM §4.2). See readme_howtointegrate.md for the pkg-config / vendored-tarball / in-tree-monorepo routes and how to pin.

Features

Modules

File	Responsibility
`spec_paths.cpp`	The section-path grammar (root / child / list-item segments).
`spec_model.cpp`	The meta-data loader — the exported class graph ( `SpecModel` , `SpecRoot` , `SpecClass` , `SpecField` , …).
`spec_reflection.cpp`	Value-free enumeration + path resolution ( `SpecReflection` , `SpecResolution` , node-kind constants).
`spec_document.cpp`	A sparse in-memory document — values keyed by section path.
`spec_typed_values.cpp`	Parse/format at the store boundary — the one place the text form of an `int` / `double` / `num` / `bool` / enum-name is decided.
`spec_editor.cpp`	The generic meta-model-driven modification API ( `SpecEditor` , YRD7) — typed edits over any path, without a generated facade.
`spec_validator.cpp`	Validates a document's values against the model.
`spec_text_pattern.cpp`	The portable pattern subset ( `SomTextPattern` ) — a hand-written leftmost-first backtracker over UTF-16 code units, so match spans agree with every other runtime ( `std::regex` is a different grammar with locale-sensitive folding).
`spec_query.cpp`	The lexical/structural query surface ( `SpecQueryEngine` , `SpecQuery` , `SpecQueryCursor` ) plus the flat tier-1 node projection ( `SpecNodeProjection` ).
`spec_node_creation.cpp`	The constrained node-creation gate ( `checkAddNode` , `SpecNodeCreator::add` ) — a document may only grow in ways the model permits.
`spec_codespecs_extract.cpp`	The Phase-4 CodeSpecs specification extract generator ( `CodeSpecsExtractor` , `CodeSpecsAreaCatalog` , `CodeSpecsExtract` ) — routes annotated nodes to areas and emits the byte-stable per-area YAML/Markdown extracts. Walks one `@Document` root, resolved at construction from an optional root-type argument ( `codespecs_prompt.md` §5).
`spec_document_yaml.cpp`	Byte-stable `*.docspecs.yaml` codec (`SOM §12`).
`spec_document_markdown.cpp`	Meta-data-driven Markdown import/export codec (`SOM §11`).
`som_facade.cpp`	Editing-facade base types ( `SomNode` , `SomList` , `joinPath` , `checkSomModelVersion` ) for the generated `tom_som_cpp_v0` .
`yaml.cpp`	Hand-rolled, dependency-free reader for the constrained docspecs YAML subset.
`som_json.cpp`	Hand-rolled, dependency-free JSON reader/encoder.
`som_util.cpp`	Small numeric/string helpers.

Quick start

#include "tom_som_cpp_runtime.hpp"

SpecDocument doc;
doc.setContent("SBP/content", "A unifying order platform.");
std::cout << doc.content("SBP/content") << '\n';
// A unifying order platform.

Usage

The generic path

Load the exported class graph, then resolve paths against it — no generated classes involved:

std::string err;
auto model = SpecModel::fromJsonStr(metaJson, err);
SpecReflection reflection(*model);

std::cout << reflection.resolve("SBP/content").has_value() << '\n';
// 1
std::cout << validateDocument(*model, doc).empty() << '\n';
// 1

Zero external dependencies

The library depends only on the C++ standard library. JSON parsing uses the hand-rolled som_json module; YAML uses the hand-rolled yaml module (the constrained docspecs subset). Byte-stable *.docspecs.yaml output requires a quoting helper that matches JavaScript's JSON.stringify exactly — it delegates to jsonEncodeStr.

Idiomatic-C++ surface

The C port was an accessor-function API over plain structs with manual ownership; this port is RAII classes and value semantics:

SpecDocument owns its three sparse byte-sorted stores; accessors return

std::string / const std::string* (the latter distinguishes unset from empty, replacing the C NULL-returning accessors). - SpecResolution is a value struct holding borrowed const pointers into the model (root / field / targetClass); resolve() returns std::optional<SpecResolution>. - SomNode holds a borrowed SpecDocument& plus an owned path; the document must outlive every facade bound to it. SomList is a path-based view over a list field. checkSomModelVersion throws SomVersionError on rejection. - validateDocument returns std::vector<SpecValidationError>; markdownParse returns a SpecMarkdownResult value. - The YAML decoder drops the review: pass — the runtime is review-agnostic and nothing in the conformance contract reads it.

Building and running the tests

Correctness is defined by the shared, language-agnostic conformance corpus in tom_som_conformance/corpus, generated from the Dart reference. This port is validated against the exact same goldens every other port uses (SOM §19):

make                 # builds the static + shared library + pkg-config file
make test            # builds + runs the conformance harness → "OK: N checks passed"
make unittest        # builds + runs the standalone unit tests
./run_conformance.sh # same as `make test`, via the wrapper script
./run_tests.sh       # conformance + the per-module suites

make produces build/libtom_som_cpp_runtime.a (static), build/libtom_som_cpp_runtime.so (shared), and build/tom_som_cpp_runtime.pc (pkg-config metadata whose Version tracks the TomSpecs model version).

The conformance harness (tests/conformance.cpp) reproduces the same checks as every other port — model meta, state.json round-trip, YAML encode/decode, Markdown export/parse/landing, reflection, validation, the imperative operations script, and the Phase-4 CodeSpecs extract tier (routing verdicts, the per-area extracts and their YAML/Markdown goldens, ROUTE-TOTAL refusals). Exit 0 == all green. The corpus directory can be overridden:

make test CORPUS=/path/to/corpus
./run_conformance.sh /path/to/corpus

Architecture

        typed path                          generic path
    tom_som_cpp_v0        ─────▶   SomNode / SomScalar / SomList
            │                                   │
            └───────────────┬───────────────────┘
                            ▼
                      SpecDocument         sparse, path-keyed value stores
                            │
        ┌───────────────────┼────────────────────┐
        ▼                   ▼                    ▼
  SpecReflection       SpecEditor          spec_document_yaml.cpp
  SpecQueryEngine      validateDocument    spec_document_markdown.cpp
        │
        ▼
     SpecModel  ◀── meta/spec_model.meta.json

Type	Responsibility
`SpecDocument`	The sparse, path-keyed store of a document's content, form and list values.
`SpecModel`	The exported class graph — roots, classes, fields, annotations.
`SpecReflection`	Resolves and enumerates paths against the model without reading values.
`SpecEditor`	Typed edits over any path, driven by the meta-model rather than by generated classes.
`SpecNodeCreator`	The creation gate — a document may only grow in ways the model permits.
`validateDocument`	The instance tier: a filled document's values checked against the model.
`SpecDocumentYaml`	Byte-stable `*.docspecs.yaml` encode/decode.
`SpecDocumentMarkdown`	DocSpecs-conform Markdown export, parse and round-trip.
`SpecQueryEngine`	Lexical/structural search over a document, matching with `SomTextPattern`.
`CodeSpecsExtractor`	The Phase-4 extract generator — one verbatim, cited extract per CodeSpecs area.
`SomNode` / `SomList`	The editing-facade base types the generated `tom_som_cpp_v0` classes extend.

Ecosystem

  tom_specs_model ──▶ tom_specs_clitool ──generate_som──▶ tom_som_cpp_v0
   (the model)          (the generator)                     (typed facade)
                                                                  │ links
                                                                  ▼
                                                      tom_som_cpp_runtime  ← this library
                                                                  │ validated against
                                                                  ▼
                                                         tom_som_conformance
                                                          (shared corpus)

Further documentation

TomSpecs subject matter — the authorities this library implements:

Document	Authority for
index.md	The catalogue of every TomSpecs subject-matter document, and the `§` citation convention.
som_multiplatform_spec_model.md	What a SOM runtime must contain, the two access paths, the `.md` and `.docspecs.yaml` formats, the validator, and the conformance corpus.
som_toolchains.md	This language plane's build and verify toolchain, and the reference host.
tom_specs_model_meta_schema.md	The on-disk schema of `meta/spec_model.meta.json`, which `SpecModel` loads.

This library — its own guides:

Guide	Covers
readme_howtointegrate.md	Every dependency route and how to pin the version.

Siblings — packages you will reach for next:

Package	What it is
tom_som_cpp_v0	The generated typed facade over this runtime — the normal path.
tom_som_c_runtime	The C reference this port transcribes.
tom_som_dart_runtime	The Dart reference the whole plane transcribes.
tom_som_conformance	The shared corpus and the cross-language drivers that run every port against it.

Status

Version 1.1.0, tracking the TomSpecs model version. Requires a C++17 compiler. Covered by 10 test files; the conformance runner reports OK: 1924 checks passed and ./run_tests.sh is green.