# `StatifierDatamodel`
[🔗](https://github.com/riddler/statifier_datamodel/blob/v0.7.1/lib/statifier_datamodel.ex#L1)

The datamodel document and what can be decided from it, with no dependency
on the block editor, the compiler, or the UI.

A datamodel document is a host's typed description of the data universe an
author writes conditions against: three scopes - `global`, `local`,
`event` - each carrying entries with a `name`, an absolute dotted `path`, a
`type` and a `label`, plus a `types` key of named record and shape
declarations, and the optional `events` and `sends` keys declaring, per
event name, the type of a payload a chart receives or sends. This package
is the reader of that document and the home of every question that can be
answered from the document alone:

  * the path/type index over an admitted document, and its projection to
    the declared-path set;
  * the declared types, and the read check - identity, then a record read
    as a shape is admitted when the record's fields cover the shape's
    required set;
  * compatibility of a redefined declaration against the one it replaces;
  * required-field coverage of a map against a shape;
  * the events a chart receives and sends, each with its payload's type,
    and the entries whose type names nothing the document declares;
  * the projection of the index to per-path value kinds an expression
    editor consumes.

Every function is pure and total over an admitted document. What is not
here, on purpose: the environment walk over a block document, which needs
the block tree and stays in `statifier_blocks`; anything that renders,
which is `statifier_ui`'s; and any runtime enforcement, which no record in
the family has asked for. Both of those packages depend on this one, and
this one depends on nothing in the family.

The document shape and the index are re-homed here from `statifier_blocks`
(its ADR-0006, accepted 2026-08-29), and ADR-0001 in this repository is the
record of the re-homing: the same three scopes, the same closed scalar set
plus `date`, the same declared-path projection, and the `types` key that
the re-homing adds.

This module is the package's root and holds no functions. The document
and its index are `StatifierDatamodel.Index` and
`StatifierDatamodel.Document`; the document's declared types are
`StatifierDatamodel.Declarations` and the type expressions over them, with
the read check, are `StatifierDatamodel.Types`. What is decided across two
declarations is `StatifierDatamodel.Compatibility`, and what is decided
between a declaration and a map is `StatifierDatamodel.Coverage`, and
whether a value conforms to a type is `StatifierDatamodel.Conformance`.
The `events` and `sends` keys are `StatifierDatamodel.Events`.

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*Consult [api-reference.md](api-reference.md) for complete listing*