Struct TypeMapping 

pub struct TypeMapping {
    pub column_name: String,
    pub source_native_type: String,
    pub rivet_type: RivetType,
    pub arrow_type: Option<DataType>,
    pub fidelity: TypeFidelity,
    pub nullable: bool,
    pub warnings: Vec<String>,
}

One row of the Type Mapping Pipeline (roadmap §6 TypeMapping).

Carries the full provenance from a source-DB column to its eventual Arrow representation. The struct is what the type-report CLI prints and what TypePolicy validates against.

Fields

column_name: String

Column name (matches SourceColumn::name).

source_native_type: String

Native source-DB type identifier (numeric(18,2), timestamptz, jsonb, …).

rivet_type: RivetType

The canonical Rivet type produced by the vendor mapper.

arrow_type: Option<DataType>

Resolved Arrow type, or None for RivetType::Unsupported until a policy turns it into something exportable.

Kept as arrow::DataType (not a stringly-typed name) so the pipeline can build an arrow::Schema directly from a Vec<TypeMapping>.

fidelity: TypeFidelity

Fidelity classification — see TypeFidelity.

nullable: bool

True when the source schema declares the column nullable. Threaded from SourceColumn::nullable so build_arrow_field doesn’t need the original column.

warnings: Vec<String>

Diagnostic strings emitted by the mapper or the policy. Surfaced by the type-report and the strict-mode failure message.

Implementations

impl TypeMapping

pub fn from_source(source: &SourceColumn, rivet_type: RivetType) -> Self

Build a mapping from a SourceColumn and an already-resolved RivetType. The Arrow type is computed by rivet_type_to_arrow and the fidelity by derive_fidelity.

This is the canonical constructor used by every vendor mapper — Chunks 2/3 will call this once per source column.

pub fn with_warning(self, msg: impl Into<String>) -> Self

Append a warning visible to the type-report and to logs.

Trait Implementations

impl Clone for TypeMapping

fn clone(&self) -> TypeMapping

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TypeMapping

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

Formats the value using the given formatter.

impl Serialize for TypeMapping

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.