FieldGen

The name of the per-instance cache of this field's base value.

Whether the field's element is a message, generated here or protobuf's own.

The test that decides whether an implicit-presence field is written.

Floats compare by raw bits rather than by value, because -0.0 == 0.0 and a value comparison would silently drop the sign of a negative zero.

Reads one element and maps it to the field's Scala type.

Reads one base-typed element.

Size of one element without its tag, for the packed encoding.

Size of one element including its tag, given an expression for the base value.

Converts a Scala-typed expression back to the base type.

Writes one element, tag included.

A value to give the field in defaultInstance when it has no constructor default.

Only reached for a required or no_box field: those deliberately have no default in the constructor, so that forgetting one is a compile error, but defaultInstance still has to produce something.

The other tag a parser must also accept for a packable repeated field.

protobuf requires readers to accept both encodings whatever the schema says, because the schema may have changed since the bytes were written.

The Scala type of one element at the proto level, before any mapping.

The field's declared Scala type, collections and Option included.

The default for the constructor parameter, or None when there must not be one.

The Scala type of one element as it appears in the generated API.

Whether parsing must fail when the field is absent.

Whether the field tracks presence, i.e. whether its Scala type is an Option.

Asks the descriptor rather than the syntax. hasPresence is resolved from the edition's field_presence feature for an editions file, from optional/required for proto2 and from the optional keyword for proto3, so one question covers all three.

Whether the field's Scala type is wrapped in Option.

Presence is necessary but not sufficient. A required field has presence - protobuf tracks whether it was set, and rejects a message where it was not - yet wrapping it would be backwards: the whole point is that it is always there. It gets a bare type and no constructor default instead, so omitting it is a compile error. no_box says the same thing for a field the schema cannot mark required.

Whether a repeated field uses the packed encoding, resolved from the features.

proto2's required, and editions' LEGACY_REQUIRED.

The TypeMapper expression, when the element's Scala type is not the base type.

The Scala name, from (field).scala_name or the camel-cased proto name.

The tag protoc writes for this field in its declared encoding.