Crate ifc_lite_core 

IFC-Lite Core Parser

High-performance STEP/IFC parser built with nom. Provides zero-copy tokenization and fast entity scanning for IFC files.

Overview

This crate provides the core parsing functionality for IFC-Lite:

• STEP Tokenization: Zero-copy parsing of STEP file format
• Entity Scanning: SIMD-accelerated entity discovery using memchr
• Lazy Decoding: On-demand attribute parsing for memory efficiency
• Streaming Parser: Event-based parsing for large files

Quick Start

use ifc_lite_core::{EntityScanner, parse_entity, IfcType};

// Scan for entities
let content = br#"#1=IFCPROJECT('guid',$,$,$,$,$,$,$,$);"#;
let mut scanner = EntityScanner::new(content);

while let Some((id, type_name, start, end)) = scanner.next_entity() {
    println!("Found entity #{}: {}", id, type_name);
}

// Parse individual entity
let input = b"#123=IFCWALL('guid',$,$,$,$,$,$,$);";
let (id, ifc_type, attrs) = parse_entity(input).unwrap();
assert_eq!(ifc_type, IfcType::IfcWall);

Streaming Parser

For large files, use the streaming parser to process entities in batches:

use ifc_lite_core::{parse_stream, StreamConfig, ParseEvent};

let config = StreamConfig::default();
for event in parse_stream(content, config) {
    match event {
        ParseEvent::Entity { id, type_name, .. } => {
            println!("Entity #{}: {}", id, type_name);
        }
        ParseEvent::Progress { percent, .. } => {
            println!("Progress: {:.1}%", percent);
        }
        _ => {}
    }
}

Performance

• Tokenization: ~1,259 MB/s throughput
• Entity scanning: ~650 MB/s with SIMD acceleration
• Number parsing: 10x faster than std using lexical-core

Re-exports

pub use columnar_index::ColumnLengthMismatch;

pub use columnar_index::ColumnarEntityIndex;

pub use compatibility::is_exporter_stratum_alias;

pub use compatibility::EXPORTER_STRATUM_ALIASES;

pub use decoder::build_entity_index;

pub use decoder::EntityDecoder;

pub use decoder::EntityIndex;

pub use decoder::GridAxisIndex;

pub use dense_index::DenseEntityIndex;

pub use error::Error;

pub use error::Result;

pub use fast_parse::extract_coordinate_list_from_entity;

pub use fast_parse::extract_coordinate_list_from_entity_f64;

pub use fast_parse::extract_entity_refs_from_list;

pub use fast_parse::extract_entity_type_name;

pub use fast_parse::extract_face_indices_from_entity;

pub use fast_parse::extract_first_entity_ref;

pub use fast_parse::parse_coordinates_direct;

pub use fast_parse::parse_indices_direct;

pub use fast_parse::process_triangulated_faceset_direct;

pub use fast_parse::should_use_fast_path;

pub use fast_parse::FastMeshData;

pub use generated::attribute_names_for_schema;

pub use generated::entity_info_for_schema;

pub use generated::is_subtype_of_for_schema;

pub use generated::IfcType;

pub use generated::SchemaEntityInfo;

pub use generated::UnknownIfcType;

pub use generated::IFC_TYPES;

pub use georef::GeoRefExtractor;

pub use georef::GeoRefSource;

pub use georef::GeoReference;

pub use limits::RtcVerdict;

pub use limits::MAX_MAPPED_ITEM_DEPTH;

pub use limits::MAX_PLACEMENT_DEPTH;

pub use model_bounds::scan_model_bounds;

pub use model_bounds::scan_placement_bounds;

pub use model_bounds::ModelBounds;

pub use parser::declared_schema_bounded;

pub use parser::entity_count;

pub use parser::find_keyword;

pub use parser::keyword_ends_with;

pub use parser::keyword_eq;

pub use parser::keyword_starts_with;

pub use parser::nth_attribute_is_present;

pub use parser::oversized_id_report;

pub use parser::parse_entity;

pub use parser::report_malformed_records;

pub use parser::report_oversized_ids;

pub use parser::report_scan_diagnostics;

pub use parser::set_report_sink;

pub use parser::skip_step_comment;

pub use parser::EntityScanner;

pub use parser::StepListItems;

pub use parser::Token;

pub use project_units::measure::measure_unit;

pub use project_units::measure::MeasureUnit;

pub use project_units::resolve_unit_by_ref;

pub use project_units::ProjectUnits;

pub use project_units::ResolvedUnit;

pub use schema_gen::AttributeValue;

pub use schema_gen::DecodedEntity;

pub use schema_gen::GeometryCategory;

pub use schema_gen::IfcSchema;

pub use schema_gen::ProfileCategory;

pub use step_encoding::decode_ifc_string;

pub use streaming::parse_stream;

pub use streaming::ParseEvent;

pub use streaming::StreamConfig;

pub use units::extract_length_unit_scale;

pub use units::extract_plane_angle_to_radians;

pub use units::get_si_prefix_multiplier;

pub use units::try_extract_length_unit_scale;

pub use units::try_extract_plane_angle_to_radians;

Modules

columnar_index

Columnar entity index — a compact, binary-searched alternative to the EntityIndex FxHashMap<u32, (usize, usize)>.

compatibility

Bounded interoperability policy for non-EXPRESS exporter spellings.

decoder

Entity Decoder - On-demand entity parsing

dense_index

Direct span lookup for dense express ids, without hash-table bucket padding.

error

express_id

The single place in this crate that decides whether a digit run read from a raw IFC byte slice fits an express id.

fast_parse

Fast Direct Parsing Module

generated

Auto-generated IFC Schema Types

georef

IFC Georeferencing Support

limits

Bounds on walks over file-supplied entity references, plus the large-coordinate threshold every crate gates the RTC re-base on (LARGE_COORD_THRESHOLD_METERS).

model_bounds

Model bounds calculation for large coordinate handling

parser

STEP/IFC Parser using nom

project_units

Canonical resolution of a file’s declared units for display.

schema_gen

IFC Schema - Dynamic type system

step_encoding

STEP string escape decoding (ISO 10303-21 / IFC).

streaming

Streaming IFC Parser

units

Unit extraction and conversion for IFC files

Functions

geometry_flags_by_name

Return the geometry-bearing and representationless-spatial predicates together. The tuple matches has_geometry_by_name and is_representationless_spatial_container_by_name, respectively, while sharing one lookup of the immutable schema classification (#3987).

has_geometry_by_name

Check if a type name (UPPERCASE STEP string) represents an IfcProduct subtype that can bear geometry (has ObjectPlacement + Representation).

ifc_type_from_keyword

Resolve a STEP keyword to its schema-local IfcType. Supported keywords retain their exact generated variants. The three non-EXPRESS exporter stratum aliases remain owned Unknown values and are handled explicitly by has_geometry_by_name. Any pass that classifies or labels an entity must use this helper rather than reimplementing keyword normalization (#4203).

ifc_type_from_record

The schema-resolved type for an entity, recovered from its RAW STEP RECORD.

is_representationless_spatial_container_by_name

Whether type_name is one of the spatial-container types that has_geometry_by_name still blocks by name (IfcBuildingStorey, IfcFacility, IfcFacilityPart, IfcSpatialElement, IfcSpatialStructureElement, and their subtypes) — i.e. IfcProduct subtypes that is_non_geometric_spatial treats as never carrying geometry directly. IfcBuilding (along with IfcSpace, IfcSite and IfcSpatialZone) is handled class-wide by has_geometry_by_name instead — see [is_non_geometric_spatial] — so it is no longer part of this instance-level exception.

is_simple_geometry_type

Check if an IFC entity class is “simple” geometry (processed first for fast first frame). Driven off the EXPRESS inheritance graph rather than a leaf-level blacklist, so new IFC4X3 subtypes (e.g. IfcSolarDevice under IfcEnergyConversionDevice) are categorised correctly without code changes — see PR #585.

type_product_ifc_type

The IfcTypeProduct subtype a STEP keyword names, or None when it is not one.