Struct FieldSchema 

pub struct FieldSchema {
    pub label: &'static str,
    pub expected_type: GffType,
    pub life: FieldLife,
    pub required: bool,
    pub absent: AbsentDefault,
    pub children: Option<&'static [FieldSchema]>,
    pub constraint: Option<FieldConstraint>,
}

Schema definition for a single GFF field.

Describes a field that can legitimately appear in a particular GFF resource type. Whether the engine reads it is FieldSchema::life, not a condition of being here.

Fields

label: &'static str

GFF field label (e.g., "Tag", "Appearance_Type").

expected_type: GffType

Expected GFF value type.

life: FieldLife

What the engine does with this label, in each direction.

FieldLife::Live for anything the engine reads, which is nearly everything here. The dead variants exist so a diagnostic can name what actually happens instead of reporting the label as unrecognized.

required: bool

Whether the engine misbehaves when this field is absent.

Set this only where an audit says the loader does something worse than substitute a default. The one traced case aborts the containing structure outright, dropping a whole gun bank rather than loading it with a zero rate of fire, so “absent” and “absent and defaulted” are not the same outcome.

An earlier version of this comment said the engine “typically falls back to a default” and treated the flag as a hint that the author probably meant to set the field. That was never audited, and the case we have since traced does the opposite. A field the loader defaults harmlessly is not required, however much an author might have meant to fill it in; leave it false.

Consumed by rakata-lint’s SCHEMA-002, which warns on absence. The severity of that warning is the same for every required field, so this stays a bool: one audited failure mode is not two, and until there are more the type costs nothing to widen later.

absent: AbsentDefault

What the engine holds when a file omits this label.

Populated from the audited format pages only. The point of sourcing it from documentation rather than from the reader is that it can then disagree with the reader, which is the whole value of the guard built on it: a round-trip check compares a reader against a writer that shares its constants, so both being wrong together looks green.

Per view, so the same label can resolve differently for different consumers. It does: an absent TrapDetectable is 1 on a door and 0 on a trigger, because a door carries its constructed value over while a trigger’s read stamps a literal.

children: Option<&'static [FieldSchema]>

Sub-schema for List elements or Struct children. None for leaf fields.

When present, validation recurses into each list element or the inner struct, checking fields against this child schema.

constraint: Option<FieldConstraint>

Optional bounds check for numeric types.

Defines min/max constraints that the engine actually honors before truncating.

Trait Implementations

impl Clone for FieldSchema

fn clone(&self) -> FieldSchema

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FieldSchema

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

Formats the value using the given formatter.