Module default_expr 

DefaultExpr — column default expression.

Three kinds:

• DefaultExpr::Literal: a typed literal (numbers, strings, bytea, NULL, etc.).
• DefaultExpr::Sequence: nextval('seq') references — recognized as desugared identity / SERIAL sources.
• DefaultExpr::Expr: any other expression, stored as a NormalizedExpr.

Real AST normalization (cast stripping, paren folding, commutative-operand sorting) lands in phase 2 once pg_query is wired in. Phase 1 ships the structural types.

Structs

NormalizedExpr

A normalized SQL expression — its canonical text plus a hash of the canonical AST.

Enums

DefaultExpr

A column-default expression.

LiteralValue

A typed literal default value.