ViewExpr.mesa
Carl Waldspurger, July 31, 1986 4:39:51 pm PDT
DIRECTORY
MathExpr USING [EXPR],
ViewerClasses USING [Viewer],
Rope USING [ROPE];
ViewExpr: CEDAR DEFINITIONS ~
BEGIN
Type Abbreviations for Imported Interfaces
ROPE: TYPE ~ Rope.ROPE;
Viewer: TYPE ~ ViewerClasses.Viewer;
EXPR: TYPE ~ MathExpr.EXPR;
Operations
Create: PROC[expr: EXPRNIL, name: ROPE] RETURNS[Viewer];
effects: Creates a new instance of an expression viewer with banner name.
Viewer will contain math expression expr. If expr = NIL, then
Viewer will contain an empty "placeholder".
GetContents: PROC[viewer: Viewer] RETURNS[ROPE];
effects: Returns the contents of viewer as a ROPE in
a format understood by the AlgebraStructures parser.
SetContents: PROC[viewer: Viewer, expr: EXPR];
modifies: viewer
effects: Changes the contents of math expression viewer viewer
to be expr.
END.