-- A Context is a stack of properties

Context: TYPE = Properties.PropList; -- order is preserved!

PropertyLiteral: TYPE = Properties.KeyVal;

PropertyLiterals: TYPE = Properties.PropList;

GetRef: PROC [context: Context, prop: ATOM] RETURNS [REF];

GetAtom: PROC [context: Context, prop: ATOM] RETURNS [ATOM];

GetRope: PROC [context: Context, prop: ATOM] RETURNS [ROPE];

GetInt: PROC [context: Context, prop: ATOM] RETURNS [INT];

GetReal: PROC [context: Context, prop: ATOM] RETURNS [REAL];

PushRef: PROC [context: Context, prop: ATOM, val: REF];

PushAtom: PROC [context: Context, prop: ATOM, val: ATOM];

PushRope: PROC [context: Context, prop: ATOM, val: ROPE];

PushInt: PROC [context: Context, prop: ATOM, val: INT];

PushReal: PROC [context: Context, prop: ATOM, val: REAL];

RegisterRefProperty: PROC [prop: ATOM];

RegisterAtomProperty: PROC [prop: ATOM];

RegisterRopeProperty: PROC [prop: ATOM];

RegisterIntProperty: PROC [prop: ATOM];

RegisterRealProperty: PROC [prop: ATOM];

CreateContext: PROC [init: Context ← NIL, props: PropertyLiterals] RETURNS [Context];

MarkContext: PROC [context: Context, mark: ATOM];

PopContext: PROC [context: Context, mark: ATOM];

StructureProc: TYPE = PROC [context: Context] RETURNS [cellType: Core.CellType];

RegisterStructureProc: PROC [name: ROPE, proc: StructureProc] RETURNS [ROPE];

CreateStructure: PROC [name: ROPE, context: Context] RETURNS [Core.CellType];