Struct MappingSchema 

pub struct MappingSchema { /* private fields */ }

A schema backed by in-memory hash maps, supporting 3-level nesting: catalog → database → table → column → type.

Analogous to Python sqlglot’s MappingSchema.

Identifiers are normalized according to the configured dialect:

• Case-insensitive dialects (most): identifiers are lowercased for lookup.
• Case-sensitive dialects (e.g. BigQuery, Hive): identifiers are kept as-is.
• Quoted identifiers are always stored verbatim (not normalized).

Implementations

impl MappingSchema

pub fn new(dialect: Dialect) -> Self

Create a new empty schema for the given dialect.

pub fn replace_table( &mut self, table_path: &[&str], columns: Vec<(String, DataType)>, ) -> Result<(), SchemaError>

Replace a table if it already exists, or add it if it doesn’t.

pub fn remove_table(&mut self, table_path: &[&str]) -> Result<bool, SchemaError>

Remove a table from the schema. Returns true if the table existed.

pub fn add_udf(&mut self, name: &str, return_type: DataType)

Register a UDF (user-defined function) with its return type.

pub fn get_udf_type(&self, name: &str) -> Option<&DataType>

Get the return type of a registered UDF.

pub fn table_names(&self) -> Vec<(String, String, String)>

List all registered tables as (catalog, database, table) triples.

Trait Implementations

impl Clone for MappingSchema

fn clone(&self) -> MappingSchema

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MappingSchema

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

Formats the value using the given formatter.

impl Schema for MappingSchema

fn add_table( &mut self, table_path: &[&str], columns: Vec<(String, DataType)>, ) -> Result<(), SchemaError>

Register a table with its column definitions.

fn column_names(&self, table_path: &[&str]) -> Result<Vec<String>, SchemaError>

Get the column names for a table, in definition order.

fn get_column_type( &self, table_path: &[&str], column: &str, ) -> Result<DataType, SchemaError>

Get the data type of a specific column in a table.

fn has_column(&self, table_path: &[&str], column: &str) -> bool

Check whether a column exists in the given table.

fn dialect(&self) -> Dialect

Get the dialect used for identifier normalization.

fn get_udf_type(&self, name: &str) -> Option<&DataType>

Get the return type of a registered UDF (user-defined function).