Enum Value 

pub enum Value {
    Null,
    Derived,
    Bool(bool),
    LogicalUnknown,
    Integer(i64),
    Real(f64),
    Text(Arc<str>),
    Binary(Arc<str>),
    Enum(Arc<str>),
    Ref(EntityId),
    List(Vec<Value>),
    Typed {
        type_name: Arc<str>,
        value: Box<Value>,
    },
}

One attribute slot in an entity.

This is deliberately a structural representation: it records what the file said, not what it means. Interpretation is the job of the domain crates.

Variants

Null

$ — the attribute is not set.

Derived

* — inherited/derived in a supertype; distinct from $.

Bool(bool)

.T. / .F.

LogicalUnknown

.U. — logical unknown, the third STEP boolean state.

Integer(i64)

An integer literal.

Real(f64)

A real literal.

Text(Arc<str>)

A quoted string, already unescaped to UTF-8.

Binary(Arc<str>)

A binary literal ("0123ABC").

Enum(Arc<str>)

An unquoted enumeration constant such as .ELEMENT.

Ref(EntityId)

A reference to another entity by its in-file id (#42).

List(Vec<Value>)

An ordered aggregate: list, set, array or bag.

Typed

A typed wrapper such as IFCLENGTHMEASURE(2.5).

Fields

type_name: Arc<str>

The declared type name, upper-cased as written.

value: Box<Value>

The wrapped value.

Implementations

impl Value

pub fn as_ref_id(&self) -> Option<EntityId>

The referenced entity, if this value is a reference.

pub fn as_bool(&self) -> Option<bool>

The boolean, if this value is .T. or .F..

.U. (logical unknown) returns None: it is a third state, not a missing boolean, and collapsing it to either would lose that.

pub fn as_i64(&self) -> Option<i64>

The integer, if this value is an integer literal.

Does not accept a real: IFC distinguishes IfcInteger from IfcReal, and silently truncating 2.7 to 2 would invent precision the file did not state.

pub fn as_text(&self) -> Option<&str>

The text content, if this is a string.

pub fn as_f64(&self) -> Option<f64>

The numeric value, accepting either integer or real.

IFC files are inconsistent about writing 1 versus 1.0 for the same attribute, so a consumer that insists on one variant will misread real files.

pub fn as_list(&self) -> Option<&[Value]>

The items, if this is an aggregate.

pub fn unwrap_typed(&self) -> &Value

Unwrap a Value::Typed to the value inside, otherwise self.

Callers almost always want the payload; the type name matters only to validation and to writers.

pub fn for_each_ref(&self, f: &mut impl FnMut(EntityId))

Visit every entity reference reachable from this value.

References nest arbitrarily deep inside aggregates, so link rewriting and integrity checks need a recursive walk rather than a shallow scan.

Trait Implementations

impl Clone for Value

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Value

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for Value

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Value