[Indigo]<AlgebraStructures>ExprsImpl.mesa!1

ExprsImpl.mesa

Last Edited by: Arnon, July 19, 1985 2:54:46 pm PDT

DIRECTORY

AlgebraClasses,

Exprs;

ExprsImpl: CEDAR PROGRAM

IMPORTS AlgebraClasses

EXPORTS Exprs

= BEGIN OPEN AC: AlgebraClasses;

Types

Object: TYPE = AC.Object;

Method: TYPE = AC.Method;

Miscellaneous Procs

Recast: AC.UnaryOp = {

toExprMethod: Method ← AC.LookupMethodForStructure[$toExpr, arg.class];

RETURN[AC.ApplyMethodNoChecks[toExprMethod, LIST[arg] ];

};

CanRecast: AC.UnaryPredicate = {

RETURN[TRUE];

};

ToExpr: AC.ToExprOp = { -- Should become a noop when MathExpr.EXPR redone as Object

data: IntData ← NARROW[in.data];

RETURN[MathConstructors.MakeInt[Convert.RopeFromInt[data^] ] ];

};

MakeCompoundExpr: AC.BinaryOp = { -- Should become a BinaryOp when MathExpr.EXPR redone as Object

};

Start Code

ExprsClass: Object ← AC.MakeClass["ExprsClass", NIL, NIL];

Exprs: PUBLIC Object ← AC.MakeStructure["Exprs", ExprsClass, NIL];

categoryMethod: Method ← AC.MakeMethod[Value, FALSE, Exprs, NEW[AC.Category ← set], NIL, NIL];

recastMethod: Method ← AC.MakeMethod[UnaryOp, TRUE, Exprs, NEW[AC.UnaryOp ← Recast], NIL, "recast"];

canRecastMethod: Method ← AC.MakeMethod[UnaryPredicate, TRUE, Exprs, NEW[AC.UnaryPredicate ← CanRecast], NIL, "canRecast"];

toExprMethod: Method ← AC.MakeMethod[ToExprOp, TRUE, Exprs, NEW[AC.ToExprOp ← ToExpr], NEW[AC.UnaryToListOp ← AC.DefaultDesiredArgStructures], "toExpr"];

compoundExprMethod: Method ← AC.MakeMethod[BinaryOp, TRUE, Exprs, NEW[AC.BinaryOp ← MakeCompoundExpr], NIL, "compoundExpr"];

AC.AddMethodToClass[$category, categoryMethod, ExprsClass];

AC.AddMethodToClass[$recast, recastMethod, ExprsClass];

AC.AddMethodToClass[$canRecast, canRecastMethod, ExprsClass];

AC.AddMethodToClass[$toExpr, toExprMethod, ExprsClass];

AC.AddMethodToClass[$compoundExpr, compoundExprMethod, ExprsClass];

AC.InstallStructure[Exprs];

END.