DEFINITION MODULE Check;

(* Resolve / check pass (two-phase, part 2).  A walk over a parsed unit's
   AST that binds identifiers to symbols, resolves and completes types,
   and emits the 2xx diagnostics -- run by the driver between Parse and
   Lower.  See docs/plan-resolve-check.md. *)

IMPORT AST;

PROCEDURE BeginSession (progName: ARRAY OF CHAR);
(* Per-session setup (alongside Lower.BeginSession). *)

PROCEDURE BeginUnit;
(* Per-unit setup (called before Parse). *)

PROCEDURE NoteForward (id: INTEGER);
(* Records a forward module-level reference noted by the parser (Design);
   FlushForward resolves it once the unit's declarations are complete. *)

PROCEDURE FlushForward;
(* Resolve every noted forward reference against the unit's declarations;
   an unresolved name is 201. *)

PROCEDURE Resolve (unit: AST.Node);
(* Resolve and check the parsed unit. *)

PROCEDURE EndSession;
(* Per-session teardown. *)

END Check.