Crate ifc_model 

ifc-model — the IFC entity graph, free of both domain semantics and serialization.

The two separations this crate exists to enforce

1. Model vs. domain meaning. Model stores entities. It does not know what a cost item, a task, a wall, or a material is. Domain crates (ifc-cost, ifc-schedule, ifc-properties, …) borrow a &Model and interpret it. Consequences:

• a thin application compiles only the domains it uses;
• data we do not understand still round-trips perfectly, because it is stored structurally rather than as a domain struct. A file full of cost entities parses and re-exports intact in a build with no cost crate at all. This is verified by tests/roundtrip.rs.

2. Model vs. serialization. Model is not “the STEP model”. STEP, ifcXML and a prospective IFC-JSON are encodings of the same graph, and each is a separate crate implementing codec::Codec. Nothing here depends on any of them — which is why format conversion is just “read with one, write with another”.

  ifc-step ──┐                        ┌── ifc-cost
  ifc-xml  ──┼── Codec ──> Model <────┼── ifc-schedule      (views)
  ifc-json ──┘   (this crate)         └── ifc-properties

Modules

Module	Role
value	The serialization-independent value model
entity	Type name plus positional attributes
model	Storage, ordering, type index, reference integrity
header	File metadata and the declared schema token
codec	The read/write trait every serialization implements
guid	IFC’s base-64 GlobalId encoding
diagnostic	Non-fatal findings a codec attaches after a recovered read
index	Derived indices: inverse references
mutation	Transactional authoring: staged edits, preflight, commit
relation	Structural relationship traversal (no domain meaning)
spatial	The spatial containment tree
traverse	Graph walks over references
error	Failure modes

Re-exports

pub use codec::Codec;

pub use diagnostic::Diagnostic;

pub use diagnostic::Severity;

pub use entity::Entity;

pub use error::ModelError;

pub use error::ModelResult;

pub use header::Header;

pub use index::Referrer;

pub use index::ReverseIndex;

pub use model::Model;

pub use mutation::Applied;

pub use mutation::Conflict;

pub use mutation::Edit;

pub use mutation::Transaction;

pub use traverse::breadth_first;

pub use traverse::depth_first;

pub use traverse::find_cycle;

pub use traverse::Budget;

pub use traverse::Stop;

pub use traverse::Walk;

pub use value::EntityId;

pub use value::Value;

Modules

codec

The serialization seam.

diagnostic

Codec-neutral, non-fatal problems found while reading a model.

entity

The entity record — a type name plus positional attributes.

error

Why a model operation failed.

guid

IFC GlobalId: the 22-character compressed GUID.

header

File-level metadata, independent of serialization.

index

Type buckets and reverse-reference indices.

model

The entity graph — storage, lookup, and nothing else.

mutation

Mutation: checked edits to entities already in the model.

traverse

Graph walks with cycle protection.

value

The IFC value model — serialization-independent.

Traits

EntitySource

Decodes the entities of a lazily loaded Model.