Trait mz_sql_parser::ast::AstInfo

source ·

pub trait AstInfo: Clone {
    type NestedStatement: AstDisplay + Clone + Hash + Debug + Eq;
    type ItemName: AstDisplay + Clone + Hash + Debug + Eq + Ord;
    type ColumnName: AstDisplay + Clone + Hash + Debug + Eq + Ord;
    type SchemaName: AstDisplay + Clone + Hash + Debug + Eq + Ord;
    type DatabaseName: AstDisplay + Clone + Hash + Debug + Eq + Ord;
    type ClusterName: AstDisplay + Clone + Hash + Debug + Eq + Ord;
    type DataType: AstDisplay + Clone + Hash + Debug + Eq + Ord;
    type CteId: Clone + Hash + Debug + Eq + Ord;
    type RoleName: AstDisplay + Clone + Hash + Debug + Eq + Ord;
    type ObjectName: AstDisplay + Clone + Hash + Debug + Eq + Ord;
}

Expand description

This represents the metadata that lives next to an AST, as we take it through various stages in the planning process.

Conceptually, when we first receive an AST from the parsing process, it only represents the syntax that the user input, and has no semantic information embedded in it. Later in this process, we want to be able to walk the tree and add additional information to it piecemeal, perhaps without going down the full planning pipeline. AstInfo represents various bits of information that get stored in the tree: for instance, at first, table names are only represented by the names the user input (in the Raw implementor of this trait), but later on, we replace them with both the name along with the ID that it gets resolved to.

Currently this process brings an Ast<Raw> to Ast<Aug>, and lives in sql/src/names.rs:resolve.