Critical Mass Modula-3: m3tk/src/sem/M3CRaisesSet.m3

m3tk/src/sem/M3CRaisesSet.m3

MODULE M3CRaisesSet;

************************************************************************* 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 M3AST_AS,  M3AST_SM;

IMPORT M3AST_AS_F, M3AST_SM_F;

IMPORT SeqM3AST_AS_Qual_used_id;

The algorithm used is only suitable for small RAISES lists but then most RAISES lists are small. It allows duplication in RAISES lists

TYPE
  DefIdList = RECORD
    array: ARRAY [0..15] OF RECORD defId: M3AST_AS.DEF_ID; mark: CARDINAL END;
    count: CARDINAL;
    next: REF DefIdList;
  END;

TYPE
  InList = {Nil, Absent, PresentSameMark, PresentOtherMark};

VAR (* CONST *)
  null_raisees_some_g := NEW(M3AST_AS.Raisees_some).init();

PROCEDURE Check(
    defId: M3AST_SM.DEF_ID_UNSET;
    mark: CARDINAL;
    VAR list: DefIdList)
    : InList
    RAISES {}=
  BEGIN
    IF defId = NIL THEN RETURN InList.Nil END;
    FOR i := 0 TO list.count - 1 DO
      WITH entry = list.array[i] DO
        IF entry.defId = defId THEN
          IF entry.mark = mark THEN
            RETURN InList.PresentSameMark;
          ELSE
            entry.mark := mark;
            RETURN InList.PresentOtherMark;
          END;
        END;
      END;
    END;
    IF list.count = NUMBER(list.array) THEN
      IF list.next = NIL THEN
        list.next := NEW(REF DefIdList, count := 0, next := NIL)
      END;
      RETURN Check(defId, mark, list.next^);
    ELSE
      WITH entry = list.array[list.count] DO
        entry.defId := defId;
        entry.mark := mark;
      END;
      INC(list.count);
      RETURN InList.Absent;
    END;
  END Check;

PROCEDURE Compare(xr1, xr2: M3AST_AS.RAISEES_NULL): Comparison RAISES {}=
  VAR r1, r2: M3AST_AS.Raisees_some;
  BEGIN
    IF xr1 = NIL THEN r1 := null_raisees_some_g
    ELSIF ISTYPE(xr1, M3AST_AS.Raisees_any) THEN r1 := NIL;
    ELSE r1 := xr1
    END;
    IF xr2 = NIL THEN r2 := null_raisees_some_g
    ELSIF ISTYPE(xr2, M3AST_AS.Raisees_any) THEN r2 := NIL;
    ELSE r2 := xr2
    END;

    IF r1 # NIL AND r2 # NIL THEN
      VAR
        dl: DefIdList;
        r: M3AST_AS.Raisees_some;
        iter: SeqM3AST_AS_Qual_used_id.Iter;
        qualId: M3AST_AS.Qual_used_id;
        count1, count2 := 0;
      BEGIN
        dl.next := NIL;
        dl.count := 0;
        FOR i := 1 TO 2 DO
          IF i = 1 THEN r := r1 ELSE r := r2 END;
          iter := SeqM3AST_AS_Qual_used_id.NewIter(r.as_raisees_s);
          WHILE SeqM3AST_AS_Qual_used_id.Next(iter, qualId) DO
            WITH inList = Check(qualId.as_id.sm_def, i, dl) DO
              IF i = 1 THEN
                IF inList = InList.Absent THEN INC(count1) END;
              ELSE
                CASE inList OF
                | InList.Absent =>
                    INC(count2);
                    IF count1 = 0 THEN
                      RETURN Comparison.ProperSubSet;
                    END;
                | InList.PresentOtherMark =>
                    DEC(count1);
                    IF count1 = 0 AND count2 > 0 THEN
                      RETURN Comparison.ProperSubSet
                    END;
                ELSE
                END;
              END;
            END;
          END;
        END;
        IF count1 = 0 THEN
          RETURN Comparison.Equal;
        ELSIF count2 = 0 THEN
          RETURN Comparison.ProperSuperSet;
        ELSE
          RETURN Comparison.Disjoint;
        END;
      END;
    ELSIF r1 = NIL AND r2 = NIL THEN
      (* neither has raises clause *)
      RETURN Comparison.Equal;
    ELSE
      (* only one has raises clause; the one without the raises clause is
       a superset of the other (because no raises clause => raises set of
       all exceptions) *)
      IF r1 = NIL THEN
        RETURN Comparison.ProperSuperSet;
      ELSE
        RETURN Comparison.ProperSubSet;
      END; (* if *)
    END; (* if *)
  END Compare;

BEGIN
END M3CRaisesSet.