Struct MappingSpec 

pub struct MappingSpec {
    pub version: u32,
    pub tables: Vec<TableMapping>,
}

Top-level mapping file.

version: 1
tables:
  - table: lake.social.users
    mode: incremental
    pipeline:
      - vertex: { label: Person, id_column: user_id, properties: [name] }
      - fk_edges:
          type: WORKS_AT
          src: { label: Person,  column: user_id }
          dst: { label: Company, column: company_id }
          properties: [since]          # edge property columns
          rename: { since: joined_at } # optional column → prop renaming

Fields

version: u32

tables: Vec<TableMapping>

Implementations

impl MappingSpec

pub fn from_yaml(yaml: &str) -> Result<Self>

pub fn load(path: impl AsRef<Path>) -> Result<Self>

pub fn from_ron(ron: &str) -> Result<Self>

Parse a MappingSpec from RON — the constellation’s RON-as-description form, sibling to from_yaml.

RON parity closes the seam the findings doc named: the Iceberg→graph mapping is now a first-class RON object like every other spec, and RON is what from_arrow_schema emits. YAML stays accepted — this is additive.

pub fn to_ron(&self) -> Result<String>

Render this spec to RON text (pretty, stable field order via the struct derive) — the round-trip partner of from_ron.

pub fn load_ron(path: impl AsRef<Path>) -> Result<Self>

Load a MappingSpec from a .ron file.

pub fn from_arrow_schema(table: &str, schema: &Schema) -> SchemaMappingCandidate

Derive a candidate MappingSpec from an Iceberg table’s Arrow schema — the schema→mapping codegen half of the RON seam.

The generator emits ONE vertex per table, a best-guess id column, the remaining scalar columns as vertex properties, and one fk_edges candidate per foreign-key-shaped (*_id) column. It is meant to be emitted as RON, reviewed, and corrected by a human — it is a starting point, not an oracle.

Honest by construction (the findings-doc law): no column is ever silently dropped. Every input field is accounted for exactly once — mapped as the id, a property, or an FK edge endpoint, or else SURFACED in SchemaMappingCandidate::unmapped (a nested/complex type that cannot become a scalar graph property). Every guessed role (the id column, each FK edge) is recorded in SchemaMappingCandidate::guesses so a reviewer knows precisely what to check.

Trait Implementations

impl Clone for MappingSpec

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 MappingSpec

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for MappingSpec

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl GraphMapping for MappingSpec

fn compile(&self) -> Result<MappingSpec>

impl Serialize for MappingSpec

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

where __S: Serializer,

Serialize this value into the given Serde serializer.