m3tk/src/gast/ASTCopy.m3

MODULE ASTCopy EXPORTS ASTCopy, AST_CopyRep;
************************************************************************* Copyright (C) Olivetti 1989 All Rights reserved Use and copy of this software and preparation of derivative works based upon this software are permitted to any person, provided this same copyright notice and the following Olivetti warranty disclaimer are included in any copy of the software or any modification thereof or derivative work therefrom made by any person. This software is made available AS IS and Olivetti disclaims all warranties with respect to this software, whether expressed or implied under any law, including all implied warranties of merchantibility and fitness for any purpose. In no event shall Olivetti be liable for any damages whatsoever resulting from loss of use, data or profits or otherwise arising out of or in connection with the use or performance of this software. ************************************************************************* 

IMPORT AST;
IMPORT ASTWalk;

REVEAL
  Handle = Handle_public BRANDED OBJECT
    ignoreChildren := FALSE;
    callOnEntry: BOOLEAN := FALSE;
    callOnExit: BOOLEAN := FALSE;
    closure: Closure := NIL;
  OVERRIDES
      Copy := DoCopy;
  END;

  Closure = OBJECT
    METHODS
      callback(n, ncopy: AST.NODE; vm: ASTWalk.VisitMode) RAISES ANY;
      init(): Closure;
    END
    BRANDED OBJECT
      handle: Handle := NIL;
    OVERRIDES
      init := Init;
  END;

PROCEDURE Nodes(
    n: AST.NODE;
    ): AST.NODE RAISES {}=
  BEGIN
    RETURN DoNodes(NEW(Handle), n);
  END Nodes;

PROCEDURE ModeNodes(
    n: AST.NODE;
    c: Closure;
    vm : ASTWalk.VisitModeControl;
    ): AST.NODE=
  VAR
    handle := NEW(Handle);
  BEGIN
    c.handle := handle;
    handle.closure := c;
    handle.callOnEntry := ASTWalk.VisitMode.Entry IN vm;
    handle.callOnExit := ASTWalk.VisitMode.Exit IN vm;
    RETURN DoNodes(handle, n);
  END ModeNodes;

PROCEDURE DoNodes(handle: Handle; n: AST.NODE): AST.NODE=
  BEGIN
    IF n = NIL THEN RETURN NIL END;
    RETURN DoCopy(handle, n);
  END DoNodes;

PROCEDURE DoCopy(handle: Handle; n: AST.NODE): AST.NODE=
  <*FATAL ANY*>
  VAR
    cn: AST.NODE := NIL;
  BEGIN
    IF handle.callOnEntry THEN
      handle.closure.callback(n, cn, ASTWalk.VisitMode.Entry);
    END;
    IF NOT handle.ignoreChildren THEN
      cn := n.copy(handle)
    END;
    IF handle.callOnExit THEN
      handle.closure.callback(n, cn, ASTWalk.VisitMode.Exit);
    END;
    RETURN cn;
  END DoCopy;
PUBLIC 
PROCEDURE IgnoreChildren(c: Closure) RAISES {} =
  BEGIN
    c.handle.ignoreChildren := TRUE;
  END IgnoreChildren;

PROCEDURE Null(<*UNUSED*> n: NODE; <*UNUSED*>handle: Handle): AST.NODE RAISES {}=
  BEGIN
    RETURN NIL;
  END Null;

PROCEDURE Init(c: Closure): Closure RAISES {}=
  BEGIN
    RETURN c;
  END Init;

BEGIN

END ASTCopy.