Version 1.1.0-alpha.4b

src/FreeOberon.Mod

@@ -19,7 +19,7 @@ along with Free Oberon.  If not, see <http://www.gnu.org/licenses/>.
 IMPORT T := TermBox, Files, Args, Utf8,
        OV, Editor, Term, FoStrings, Config, Strings, Int, Out, Kernel;
 CONST
-  version* = '1.1.0-alpha.4';
+  version* = '1.1.0-alpha.4b';
   year = 2022;
 
   (* Direction of Selection *)

src/Texts0.Mod

@@ -1,938 +0,0 @@
-MODULE Texts;  (** CAS/HM 23.9.93 -- interface based on Texts by JG/NW 6.12.91**)  (* << RC, MB, JT *)
-  IMPORT
-    s := SYSTEM, Files, Modules, Reals;
-
-  TYPE
-    SHORTINT = s.INT8; INTEGER = s.INT16; LONGINT = s.INT32; HUGEINT = s.INT64;
-    CHAR = s.CHAR8; LONGCHAR = s.CHAR16; REAL = s.REAL32; LONGREAL = s.REAL64;
-
-  (*--- insert field e: Elem into Texts.Scanner and change Texts.Scan to set it in case of class=6 *)
-
-
-  CONST
-    Displaywhite = 15;
-    ElemChar* = 1CX;
-    TAB = 9X; CR = 0DX; maxD = 9;
-    (**FileMsg.id**)
-      load* = 0; store* = 1;
-    (**Notifier op**)
-      replace* = 0; insert* = 1; delete* = 2; unmark* = 3;
-    (**Scanner.class**)
-      Inval* = 0; Name* = 1; String* = 2; Int* = 3; Real* = 4; LongReal* = 5; Char* = 6;
-
-    textTag = 0F0X; DocBlockId = 0F7X; version = 01X;
-
-  TYPE
-    FontsFont = POINTER TO FontDesc;
-    FontDesc = RECORD
-      name: ARRAY 32 OF CHAR;
-    END ;
-
-    Run = POINTER TO RunDesc;
-    RunDesc = EXTENSIBLE RECORD
-      prev, next: Run;
-      len: LONGINT;
-      fnt: FontsFont;
-      col, voff: SHORTINT;
-      ascii: BOOLEAN  (* << *)
-    END;
-
-    Piece = POINTER TO PieceDesc;
-    PieceDesc = RECORD (RunDesc)
-      file: Files.File;
-      org: LONGINT
-    END;
-
-    Elem* = POINTER TO ElemDesc;
-    Buffer* = POINTER TO BufDesc;
-    Text* = POINTER TO TextDesc;
-
-    ElemMsg* = EXTENSIBLE RECORD END;
-    Handler* = PROCEDURE (e: Elem; VAR msg: ElemMsg);
-
-    ElemDesc* = EXTENSIBLE RECORD (RunDesc)
-      W*, H*: LONGINT;
-      handle*: Handler;
-      base: Text
-    END;
-
-    FileMsg* = RECORD (ElemMsg)
-      id*: INTEGER;
-      pos*: LONGINT;
-      r*: Files.Rider
-    END;
-
-    CopyMsg* = RECORD (ElemMsg)
-      e*: Elem
-    END;
-
-    IdentifyMsg* = RECORD (ElemMsg)
-      mod*, proc*: ARRAY 32 OF CHAR
-    END;
-
-
-    BufDesc* = RECORD
-      len*: LONGINT;
-      head: Run
-    END;
-
-    Notifier* = PROCEDURE (T: Text; op: INTEGER; beg, end: LONGINT);
-    TextDesc* = RECORD
-      len*: LONGINT;
-      notify*: Notifier;
-      head, cache: Run;
-      corg: LONGINT
-    END;
-
-    Reader* = EXTENSIBLE RECORD
-      eot*: BOOLEAN;
-      fnt*: FontsFont;
-      col*, voff*: SHORTINT;
-      elem*: Elem;
-      rider: Files.Rider;
-      run: Run;
-      org, off: LONGINT
-    END;
-
-    Scanner* = RECORD (Reader)
-      nextCh*: CHAR;
-      line*, class*: INTEGER;
-      i*: LONGINT;
-      x*: REAL;
-      y*: LONGREAL;
-      c*: CHAR;
-      len*: SHORTINT;
-      s*: ARRAY 64 OF CHAR  (* << *)
-    END;
-
-    Writer* = RECORD
-      buf*: Buffer;
-      fnt*: FontsFont;
-      col*, voff*: SHORTINT;
-      rider: Files.Rider;
-      file: Files.File
-    END;
-
-    Alien = POINTER TO RECORD (ElemDesc)
-      file: Files.File;
-      org, span: LONGINT;
-      mod, proc: ARRAY 32 OF CHAR
-    END;
-
-  VAR
-    new*: Elem;
-    del: Buffer;
-    FontsDefault: FontsFont;
-
-
-  PROCEDURE FontsThis(VAR name: ARRAY OF CHAR): FontsFont;
-    VAR F: FontsFont;
-  BEGIN
-    NEW(F); F.name := name$; RETURN F
-  END FontsThis;
-
-  (* run primitives *)
-
-  PROCEDURE Find (T: Text; VAR pos: LONGINT; VAR u: Run; VAR org, off: LONGINT);
-    VAR v: Run; m: LONGINT;
-  BEGIN
-    IF pos >= T.len THEN pos := T.len; u := T.head; org := T.len; off := 0; T.cache := T.head; T.corg := 0
-    ELSE v := T.cache.next; m := pos - T.corg;
-      IF pos >= T.corg THEN
-        WHILE m >= v.len DO DEC(m, v.len); v := v.next END
-      ELSE
-        WHILE m < 0 DO v := v.prev; INC(m, v.len) END;
-      END;
-      u := v; org := pos - m; off := m; T.cache := v.prev; T.corg := org
-    END
-  END Find;
-
-  PROCEDURE Split (off: LONGINT; VAR u, un: Run);
-    VAR p, U: Piece;
-  BEGIN
-    IF off = 0 THEN un := u; u := un.prev
-    ELSIF off >= u.len THEN un := u.next
-    ELSE NEW(p); un := p; U := u(Piece);
-      p^ := U^; INC(p.org, off); DEC(p.len, off); DEC(U.len, p.len);
-      p.ascii := u.ascii; p.prev := U; p.next := U.next; p.next.prev := p; U.next := p  (* << *)
-    END
-  END Split;
-
-  PROCEDURE Merge (T: Text; u: Run; VAR v: Run);
-    VAR p, q: Piece;
-  BEGIN
-    IF (u IS Piece) & (v IS Piece) & (u.fnt.name = v.fnt.name) & (u.col = v.col) & (u.voff = v.voff)
-    & (u(Piece).ascii = v(Piece).ascii) THEN  (* << *)
-      p := u(Piece); q := v(Piece);
-      IF (p.file = q.file) & (p.org + p.len = q.org) THEN
-        IF T.cache = u THEN INC(T.corg, q.len)
-        ELSIF T.cache = v THEN T.cache := T.head; T.corg := 0
-        END;
-        INC(p.len, q.len); v := v.next
-      END
-    END
-  END Merge;
-
-  PROCEDURE Splice (un, v, w: Run; base: Text);  (* (u, un) -> (u, v, w, un) *)
-    VAR u: Run;
-  BEGIN
-    IF v # w.next THEN u := un.prev;
-      u.next := v; v.prev := u; un.prev := w; w.next := un;
-      REPEAT
-        IF v IS Elem THEN v(Elem).base := base END;
-        v := v.next
-      UNTIL v = un
-    END
-  END Splice;
-
-  PROCEDURE ClonePiece (p: Piece): Piece;
-    VAR q: Piece;
-  BEGIN NEW(q); q^ := p^; RETURN q
-  END ClonePiece;
-
-  PROCEDURE CloneElem (e: Elem): Elem;
-    VAR msg: CopyMsg;
-  BEGIN msg.e := NIL; e.handle(e, msg); RETURN msg.e
-  END CloneElem;
-
-
-  (** Elements **)
-
-  PROCEDURE CopyElem* (SE, DE: Elem);
-  BEGIN DE.len := SE.len; DE.fnt := SE.fnt; DE.col := SE.col; DE.voff := SE.voff;
-    DE.W := SE.W; DE.H := SE.H; DE.handle := SE.handle
-  END CopyElem;
-
-  PROCEDURE ElemBase* (E: Elem): Text;
-  BEGIN RETURN E.base
-  END ElemBase;
-
-  PROCEDURE ElemPos* (E: Elem): LONGINT;
-    VAR u: Run; pos: LONGINT;
-  BEGIN u := E.base.head.next; pos := 0;
-    WHILE u # E DO pos := pos + u.len; u := u.next END;
-    RETURN pos
-  END ElemPos;
-
-
-  PROCEDURE HandleAlien (E: Elem; VAR msg: ElemMsg);
-    VAR e: Alien; r: Files.Rider; i: LONGINT; ch: CHAR;
-  BEGIN
-    WITH E: Alien DO
-      IF msg IS CopyMsg THEN
-        WITH msg: CopyMsg DO NEW(e); CopyElem(E, e);
-          e.file := E.file; e.org := E.org; e.span := E.span; e.mod := E.mod; e.proc := E.proc;
-          msg.e := e
-        END
-      ELSIF msg IS IdentifyMsg THEN
-        WITH msg: IdentifyMsg DO
-          msg.mod := E.mod$; msg.proc := E.proc$; msg.mod[31] := 1X (*alien*)
-        END
-      ELSIF msg IS FileMsg THEN
-        WITH msg: FileMsg DO
-          IF msg.id = store THEN Files.Set(r, E.file, E.org); i := E.span;
-            WHILE i > 0 DO Files.ReadChar(r, ch); Files.WriteChar(msg.r, ch); DEC(i) END
-          END
-        END
-      END
-    END
-  END HandleAlien;
-
-
-  (** Buffers **)
-
-  PROCEDURE OpenBuf* (B: Buffer);
-    VAR u: Run;
-  BEGIN NEW(u); u.next := u; u.prev := u; B.head := u; B.len := 0
-  END OpenBuf;
-
-  PROCEDURE Copy* (SB, DB: Buffer);
-    VAR u, v, vn: Run;
-  BEGIN u := SB.head.next; v := DB.head.prev;
-    WHILE u # SB.head DO
-      IF u IS Piece THEN vn := ClonePiece(u(Piece)) ELSE vn := CloneElem(u(Elem)) END;
-      v.next := vn; vn.prev := v; v := vn; u := u.next
-    END;
-    v.next := DB.head; DB.head.prev := v;
-    INC(DB.len, SB.len)
-  END Copy;
-
-  PROCEDURE Recall* (VAR B: Buffer);
-  BEGIN B := del; del := NIL
-  END Recall;
-
-
-  (** Texts **)
-
-  PROCEDURE Save* (T: Text; beg, end: LONGINT; B: Buffer);
-    VAR u, v, w, wn: Run; uo, ud, vo, vd: LONGINT;
-  BEGIN Find(T, beg, u, uo, ud); Find(T, end, v, vo, vd);
-    w := B.head.prev;
-    WHILE u # v DO
-      IF u IS Piece THEN wn := ClonePiece(u(Piece)); DEC(wn.len, ud); INC(wn(Piece).org, ud)
-      ELSE wn := CloneElem(u(Elem))
-      END;
-      w.next := wn; wn.prev := w; w := wn; u := u.next; ud := 0
-    END;
-    IF vd > 0 THEN (*v IS Piece*) wn := ClonePiece(v(Piece)); wn.len := vd - ud; INC(wn(Piece).org, ud);
-      w.next := wn; wn.prev := w; w := wn
-    END;
-    w.next := B.head; B.head.prev := w;
-    INC(B.len, end - beg)
-  END Save;
-
-  PROCEDURE Insert* (T: Text; pos: LONGINT; B: Buffer);
-    VAR u, un, v: Run; p, q: Piece; uo, ud, len: LONGINT;
-  BEGIN Find(T, pos, u, uo, ud); Split(ud, u, un);
-    len := B.len; v := B.head.next;
-    Merge(T, u, v); Splice(un, v, B.head.prev, T);
-    INC(T.len, len); B.head.next := B.head; B.head.prev := B.head; B.len := 0;
-    IF T.notify # NIL THEN T.notify(T, insert, pos, pos+len) END
-  END Insert;
-
-  PROCEDURE Append* (T: Text; B: Buffer);
-    VAR v: Run; pos, len: LONGINT;
-  BEGIN pos := T.len; len := B.len; v := B.head.next;
-    Merge(T, T.head.prev, v); Splice(T.head, v, B.head.prev, T);
-    INC(T.len, len); B.head.next := B.head; B.head.prev := B.head; B.len := 0;
-    IF T.notify # NIL THEN T.notify(T, insert, pos, pos+len) END
-  END Append;
-
-  PROCEDURE Delete* (T: Text; beg, end: LONGINT);
-    VAR c, u, un, v, vn: Run; co, uo, ud, vo, vd: LONGINT;
-  BEGIN
-    Find(T, beg, u, uo, ud); Split(ud, u, un); c := T.cache; co := T.corg;
-    Find(T, end, v, vo, vd); Split(vd, v, vn); T.cache := c; T.corg := co;
-    NEW(del); OpenBuf(del); del.len := end - beg;
-    Splice(del.head, un, v, NIL);
-    Merge(T, u, vn); u.next := vn; vn.prev := u;
-    DEC(T.len, end - beg);
-    IF T.notify # NIL THEN T.notify(T, delete, beg, end) END
-  END Delete;
-
-  PROCEDURE ChangeLooks* (T: Text; beg, end: LONGINT; sel: SET; fnt: FontsFont; col, voff: SHORTINT);
-    VAR c, u, un, v, vn: Run; co, uo, ud, vo, vd: LONGINT;
-  BEGIN Find(T, beg, u, uo, ud); Split(ud, u, un); c := T.cache; co := T.corg;
-    Find(T, end, v, vo, vd); Split(vd, v, vn); T.cache := c; T.corg := co;
-    WHILE un # vn DO
-      IF (0 IN sel) & (fnt # NIL) THEN un.fnt := fnt END;
-      IF 1 IN sel THEN un.col := col END;
-      IF 2 IN sel THEN un.voff := voff END;
-      Merge(T, u, un);
-      IF u.next = un THEN u := un; un := un.next ELSE u.next := un; un.prev := u END
-    END;
-    Merge(T, u, un); u.next := un; un.prev := u;
-    IF T.notify # NIL THEN T.notify(T, replace, beg, end) END
-  END ChangeLooks;
-
-
-  (** Readers **)
-
-  PROCEDURE OpenReader* (VAR R: Reader; T: Text; pos: LONGINT);
-    VAR u: Run;
-  BEGIN
-    IF pos >= T.len THEN pos := T.len ELSIF pos < 0 THEN pos := 0 END;
-    Find(T, pos, u, R.org, R.off); R.run := u; R.eot := FALSE;
-    IF u IS Piece THEN
-      Files.Set(R.rider, u(Piece).file, u(Piece).org + R.off)
-    END
-  END OpenReader;
-
-  PROCEDURE Read* (VAR R: Reader; OUT ch: CHAR);
-    VAR u: Run; pos: LONGINT; nextch: CHAR;
-  BEGIN u := R.run; R.fnt := u.fnt; R.col := u.col; R.voff := u.voff; INC(R.off);
-    IF u IS Piece THEN Files.ReadChar(R.rider, ch); R.elem := NIL;
-      IF (ch = 0AX) & u(Piece).ascii THEN ch := CR (* << LF to CR *)
-      ELSIF (ch = CR) & u(Piece).ascii THEN (* << CR LF to CR *)
-         pos := SHORT(Files.Pos(R.rider)); Files.ReadChar(R.rider, nextch);
-         IF nextch = 0AX THEN INC(R.off) ELSE Files.Set(R.rider, u(Piece).file, pos) END
-      END
-    ELSIF u IS Elem THEN ch := ElemChar; R.elem := u(Elem)
-    ELSE ch := 0X; R.elem := NIL; R.eot := TRUE
-    END;
-    IF R.off = u.len THEN INC(R.org, u.len); u := u.next;
-      IF u IS Piece THEN
-        WITH u: Piece DO Files.Set(R.rider, u.file, u.org) END
-      END;
-      R.run := u; R.off := 0
-    END
-  END Read;
-
-  PROCEDURE ReadLong* (VAR R: Reader; OUT longch: LONGCHAR): BOOLEAN;
-    VAR ch: CHAR; val: LONGINT;
-  BEGIN Read(R, ch);
-    IF ch < 80X THEN
-      longch := ch
-    ELSIF ch < 0E0X THEN
-      val := ORD(ch) - 192;
-      IF val < 0 THEN RETURN FALSE END;
-      Read(R, ch); val := val * 64 + ORD(ch) - 128;
-      IF (ch < 80X) OR (ch >= 0E0X) THEN RETURN FALSE END;
-      longch := CHR(val)
-    ELSIF ch < 0F0X THEN 
-      val := ORD(ch) - 224;
-      Read(R, ch); val := val * 64 + ORD(ch) - 128;
-      IF (ch < 80X) OR (ch >= 0E0X) THEN RETURN FALSE END;
-      Read(R, ch); val := val * 64 + ORD(ch) - 128;
-      IF (ch < 80X) OR (ch >= 0E0X) THEN RETURN FALSE END;
-      longch := CHR(val)
-    ELSE
-      RETURN FALSE
-    END;
-    RETURN TRUE
-  END ReadLong;
-
-  PROCEDURE ReadElem* (VAR R: Reader);
-    VAR u, un: Run;
-  BEGIN u := R.run;
-    WHILE u IS Piece DO INC(R.org, u.len); u := u.next END;
-    IF u IS Elem THEN un := u.next; R.run := un; INC(R.org); R.off := 0;
-      R.fnt := u.fnt; R.col := u.col; R.voff := u.voff; R.elem := u(Elem);
-      IF un IS Piece THEN
-        WITH un: Piece DO Files.Set(R.rider, un.file, un.org) END
-      END
-    ELSE R.eot := TRUE; R.elem := NIL
-    END
-  END ReadElem;
-
-  PROCEDURE ReadPrevElem* (VAR R: Reader);
-    VAR u: Run;
-  BEGIN u := R.run.prev;
-    WHILE u IS Piece DO DEC(R.org, u.len); u := u.prev END;
-    IF u IS Elem THEN R.run := u; DEC(R.org); R.off := 0;
-      R.fnt := u.fnt; R.col := u.col; R.voff := u.voff; R.elem := u(Elem)
-    ELSE R.eot := TRUE; R.elem := NIL
-    END
-  END ReadPrevElem;
-
-  PROCEDURE Pos* (VAR R: Reader): LONGINT;
-  BEGIN RETURN R.org + R.off
-  END Pos;
-
-
-  (** Scanners --------------- NW --------------- **)
-
-  PROCEDURE OpenScanner* (VAR S: Scanner; T: Text; pos: LONGINT);
-  BEGIN OpenReader(S, T, pos); S.line := 0; S.nextCh := " "
-  END OpenScanner;
-
-  (*IEEE floating point formats:
-    x = 2^(e-127) * 1.m    bit 0: sign, bits 1- 8: e, bits  9-31: m
-    x = 2^(e-1023) * 1.m   bit 0: sign, bits 1-11: e, bits 12-63: m *)
-
-  PROCEDURE Scan* (VAR S: Scanner);
-    CONST maxD = 32;
-    VAR ch, term: CHAR;
-      neg, negE, hex: BOOLEAN;
-      i, j, h: SHORTINT;
-      e: INTEGER; k: LONGINT;
-      x, f: REAL; y, g: LONGREAL;
-      d: ARRAY maxD OF CHAR;
-
-    PROCEDURE ReadScaleFactor;
-    BEGIN Read(S, ch);
-      IF ch = "-" THEN negE := TRUE; Read(S, ch)
-      ELSE negE := FALSE;
-        IF ch = "+" THEN Read(S, ch) END
-      END;
-      WHILE ("0" <= ch) & (ch <= "9") DO
-        e := SHORT(e*10 + ORD(ch) - 30H); Read(S, ch)
-      END
-    END ReadScaleFactor;
-
-  BEGIN ch := S.nextCh; i := 0;
-    LOOP
-      IF ch = CR THEN INC(S.line)
-      ELSIF (ch # " ") & (ch # TAB) THEN EXIT
-      END ;
-      Read(S, ch)
-    END;
-    IF ("A" <= CAP(ch)) & (CAP(ch) <= "Z") OR (ch = "/") OR (ch = ".") THEN (*name*)  (* << *)
-      REPEAT S.s[i] := ch; INC(i); Read(S, ch)
-      UNTIL (CAP(ch) > "Z") & (ch # "_")  (* << *)
-        OR ("A" > CAP(ch)) & (ch > "9")
-        OR ("0" > ch) & (ch # ".") & (ch # "/")  (* << *)
-        OR (i = 63);  (* << *)
-      S.s[i] := 0X; S.len := i; S.class := 1
-    ELSIF ch = 22X THEN (*literal string*)
-      Read(S, ch);
-      WHILE (ch # 22X) & (ch >= " ") & (i # 63) DO  (* << *)
-        S.s[i] := ch; INC(i); Read(S, ch)
-      END;
-      S.s[i] := 0X; S.len := SHORT(SHORT(i+1)); Read(S, ch); S.class := 2
-    ELSE
-      IF ch = "-" THEN neg := TRUE; Read(S, ch) ELSE neg := FALSE END ;
-      IF ("0" <= ch) & (ch <= "9") THEN (*number*)
-        hex := FALSE; j := 0;
-        LOOP d[i] := ch; INC(i); Read(S, ch);
-          IF ch < "0" THEN EXIT END;
-          IF "9" < ch THEN
-            IF ("A" <= ch) & (ch <= "F") THEN hex := TRUE; ch := SHORT(CHR(ORD(ch)-7))
-            ELSIF ("a" <= ch) & (ch <= "f") THEN hex := TRUE; ch := SHORT(CHR(ORD(ch)-27H))
-            ELSE EXIT
-            END
-          END
-        END;
-        IF ch = "H" THEN (*hex number*)
-          Read(S, ch); S.class := 3;
-          IF i-j > 8 THEN j := SHORT(SHORT(i-8)) END;
-          k := ORD(d[j]) - 30H; INC(j);
-          IF (i-j = 7) & (k >= 8) THEN DEC(k, 16) END ;
-          WHILE j < i DO k := k*10H + (ORD(d[j]) - 30H); INC(j) END ;
-          IF neg THEN S.i := -k ELSE S.i := k END
-        ELSIF ch = "." THEN (*read real*)
-          Read(S, ch); h := i;
-          WHILE ("0" <= ch) & (ch <= "9") DO d[i] := ch; INC(i); Read(S, ch) END ;
-          IF ch = "D" THEN
-            e := 0; y := 0; g := 1;
-            REPEAT y := y*10 + (ORD(d[j]) - 30H); INC(j) UNTIL j = h;
-            WHILE j < i DO g := g/10; y := (ORD(d[j]) - 30H)*g + y; INC(j) END ;
-            ReadScaleFactor;
-            IF negE THEN
-              IF e <= 308 THEN y := y / Reals.TenL(e) ELSE y := 0 END
-            ELSIF e > 0 THEN
-              IF e <= 308 THEN y := Reals.TenL(e) * y ELSE HALT(40) END
-            END ;
-            IF neg THEN y := -y END ;
-            S.class := 5; S.y := y
-          ELSE e := 0; x := 0; f := 1;
-            REPEAT x := x*10 + (ORD(d[j]) - 30H); INC(j) UNTIL j = h;
-            WHILE j < i DO f := f/10; x := (ORD(d[j])-30H)*f + x; INC(j) END;
-            IF ch = "E" THEN ReadScaleFactor END ;
-            IF negE THEN
-              IF e <= 38 THEN x := x / Reals.Ten(e) ELSE x := 0 END
-            ELSIF e > 0 THEN
-              IF e <= 38 THEN x := Reals.Ten(e) * x ELSE HALT(40) END
-            END ;
-            IF neg THEN x := -x END ;
-            S.class := 4; S.x := x
-          END ;
-          IF hex THEN S.class := 0 END
-        ELSE (*decimal integer*)
-          S.class := 3; k := 0;
-          REPEAT k := k*10 + (ORD(d[j]) - 30H); INC(j) UNTIL j = i;
-          IF neg THEN S.i := -k ELSE S.i := k END;
-          IF hex THEN S.class := 0 ELSE S.class := 3 END
-        END
-      ELSE S.class := 6;
-        IF neg THEN S.c := "-" ELSE S.c := ch; Read(S, ch) END
-      END
-    END;
-    S.nextCh := ch
-  END Scan;
-
-
-  (** Writers **)
-
-  PROCEDURE OpenWriter* (VAR W: Writer);
-  BEGIN NEW(W.buf); OpenBuf(W.buf);
-    W.fnt := FontsDefault; W.col := Displaywhite; W.voff := 0;
-    W.file := Files.New(""); Files.Set(W.rider, W.file, 0)
-  END OpenWriter;
-
-  PROCEDURE SetFont* (VAR W: Writer; fnt: FontsFont);
-  BEGIN W.fnt := fnt
-  END SetFont;
-
-  PROCEDURE SetColor* (VAR W: Writer; col: SHORTINT);
-  BEGIN W.col := col
-  END SetColor;
-
-  PROCEDURE SetOffset* (VAR W: Writer; voff: SHORTINT);
-  BEGIN W.voff := voff
-  END SetOffset;
-
-
-  PROCEDURE Write* (VAR W: Writer; ch: CHAR);
-    VAR u, un: Run; p: Piece;
-  BEGIN Files.WriteChar(W.rider, ch); INC(W.buf.len); un := W.buf.head; u := un.prev;
-    IF (u IS Piece) & (u(Piece).file = W.file) & (u.fnt.name = W.fnt.name) & (u.col = W.col) & (u.voff = W.voff)
-    & ~u(Piece).ascii THEN (* << *)
-      INC(u.len)
-    ELSE NEW(p); u.next := p; p.prev := u; p.next := un; un.prev := p;
-      p.len := 1; p.fnt := W.fnt; p.col := W.col; p.voff := W.voff;
-      p.file := W.file; p.org := SHORT(Files.Length(W.file)) - 1; p.ascii := FALSE (* << *)
-    END
-  END Write;
-
-  PROCEDURE WriteElem* (VAR W: Writer; e: Elem);
-    VAR u, un: Run;
-  BEGIN
-    IF e.base # NIL THEN HALT(99) END;
-    INC(W.buf.len); e.len := 1; e.fnt := W.fnt; e.col := W.col; e.voff := W.voff;
-    un := W.buf.head; u := un.prev; u.next := e; e.prev := u; e.next := un; un.prev := e
-  END WriteElem;
-
-  PROCEDURE WriteLn* (VAR W: Writer);
-  BEGIN Write(W, CR)
-  END WriteLn;
-
-  PROCEDURE WriteString* (VAR W: Writer; IN s: ARRAY OF CHAR);
-    VAR i: INTEGER;
-  BEGIN i := 0;
-    WHILE s[i] >= " " DO Write(W, s[i]); INC(i) END
-  END WriteString;
-
-  PROCEDURE WriteInt* (VAR W: Writer; x, n: LONGINT);
-  VAR
-    i: INTEGER; x0: LONGINT;
-    a: ARRAY 22 OF CHAR;
-  BEGIN i := 0;
-    IF x < 0 THEN
-      IF x = MIN(LONGINT) THEN
-        IF SIZE(LONGINT) = 4 THEN
-          WriteString(W, " -2147483648")
-        ELSE
-          WriteString(W, " -9223372036854775808")
-        END;
-        RETURN
-      ELSE DEC(n); x0 := -x
-      END
-    ELSE x0 := x
-    END;
-    REPEAT
-      a[i] := SHORT(CHR(x0 MOD 10 + 30H)); x0 := x0 DIV 10; INC(i)
-    UNTIL x0 = 0;
-    WHILE n > i DO Write(W, " "); DEC(n) END;
-    IF x < 0 THEN Write(W, "-") END;
-    REPEAT DEC(i); Write(W, a[i]) UNTIL i = 0
-  END WriteInt;
-
-  PROCEDURE WriteLongInt* (VAR W: Writer; x: HUGEINT; n: LONGINT);
-  VAR
-    i: LONGINT; x0: HUGEINT;
-    a: ARRAY 22 OF CHAR;
-  BEGIN i := 0;
-    IF x < 0 THEN
-      IF x = MIN(HUGEINT) THEN
-        IF SIZE(HUGEINT) = 4 THEN
-          WriteString(W, " -2147483648")
-        ELSE
-          WriteString(W, " -9223372036854775808")
-        END;
-        RETURN
-      ELSE DEC(n); x0 := -x
-      END
-    ELSE x0 := x
-    END;
-    REPEAT
-      a[i] := SHORT(CHR(x0 MOD 10 + 30H)); x0 := x0 DIV 10; INC(i)
-    UNTIL x0 = 0;
-    WHILE n > i DO Write(W, " "); DEC(n) END;
-    IF x < 0 THEN Write(W, "-") END;
-    REPEAT DEC(i); Write(W, a[i]) UNTIL i = 0
-  END WriteLongInt;
-
-  PROCEDURE WriteHex* (VAR W: Writer; x: LONGINT);
-    VAR i: INTEGER; y: LONGINT;
-      a: ARRAY 8 OF CHAR;
-  BEGIN i := 0; Write(W, " ");
-    REPEAT y := x MOD 10H;
-      IF y < 10 THEN a[i] := SHORT(CHR(y + 30H)) ELSE a[i] := SHORT(CHR(y + 37H)) END;
-      x := x DIV 10H; INC(i)
-    UNTIL i = 8;
-    REPEAT DEC(i); Write(W, a[i]) UNTIL i = 0
-  END WriteHex;
-
-  PROCEDURE WriteLongHex* (VAR W: Writer; x: HUGEINT);
-    VAR i: INTEGER; y: LONGINT;
-      a: ARRAY 16 OF CHAR;
-  BEGIN i := 0; Write(W, " ");
-    REPEAT y := SHORT(x) MOD 10H;
-      IF y < 10 THEN a[i] := SHORT(CHR(y + 30H)) ELSE a[i] := SHORT(CHR(y + 37H)) END;
-      x := x DIV 10H; INC(i)
-    UNTIL i = 16;
-    REPEAT DEC(i); Write(W, a[i]) UNTIL i = 0
-  END WriteLongHex;
-
-  PROCEDURE WriteReal* (VAR W: Writer; x: REAL; n: INTEGER);
-    VAR e: INTEGER; x0: REAL;
-      d: ARRAY maxD OF CHAR;
-  BEGIN e := Reals.Expo(x);
-    IF e = 0 THEN
-      WriteString(W, "0.0");
-      REPEAT DEC(n) UNTIL n <= 3
-    ELSIF e = 255 THEN
-      WriteString(W, "NaN");
-    ELSE
-      IF n <= 9 THEN n := 3 ELSE DEC(n, 6) END;
-      REPEAT DEC(n) UNTIL n <= 8;
-      (*there are 2 < n <= 8 digits to be written*)
-      IF x < 0.0 THEN Write(W, "-"); x := -x END;
-      e := SHORT((e - 127) * 77 DIV 256);
-      IF e >= 0 THEN x := x / Reals.Ten(e) ELSE x := Reals.Ten(SHORT(-e)) * x END;
-      IF x >= 10.0 THEN x := 0.1*x; INC(e) END;
-      x0 := Reals.Ten(SHORT(n-1)); x := x0*x + 0.5;
-      IF x >= 10.0*x0 THEN x := x*0.1; INC(e) END;
-      Reals.Convert(x, n, d);
-      DEC(n); Write(W, d[n]); Write(W, ".");
-      REPEAT DEC(n); Write(W, d[n]) UNTIL n = 0;
-      Write(W, "E");
-      IF e >= 0 THEN Write(W, "+") END;
-      WriteInt(W, e, 0)
-    END
-  END WriteReal;
-
-  PROCEDURE WriteRealFix* (VAR W: Writer; x: REAL; n, k: INTEGER);
-    VAR e, i: INTEGER; sign: CHAR; x0: REAL;
-      d: ARRAY maxD OF CHAR;
-
-    PROCEDURE seq(ch: CHAR; n: INTEGER);
-    BEGIN WHILE n > 0 DO Write(W, ch); DEC(n) END
-    END seq;
-
-    PROCEDURE dig(n: INTEGER);
-    BEGIN
-      WHILE n > 0 DO
-        DEC(i); Write(W, d[i]); DEC(n)
-      END
-    END dig;
-
-  BEGIN e := Reals.Expo(x);
-    IF k < 0 THEN k := 0 END;
-    IF e = 0 THEN seq(" ", SHORT(n-k-2)); Write(W, "0"); seq(" ", SHORT(k+1))
-    ELSIF e = 255 THEN WriteString(W, " NaN"); seq(" ", SHORT(n-4))
-    ELSE e := SHORT((e - 127) * 77 DIV 256);
-      IF x < 0 THEN sign := "-"; x := -x ELSE sign := " " END;
-      IF e >= 0 THEN  (*x >= 1.0,  77/256 = log 2*) x := x/Reals.Ten(e)
-        ELSE (*x < 1.0*) x := Reals.Ten(SHORT(-e)) * x
-      END;
-      IF x >= 10.0 THEN x := 0.1*x; INC(e) END;
-      (* 1 <= x < 10 *)
-      IF k+e >= maxD-1 THEN k := SHORT(maxD-1-e)
-        ELSIF k+e < 0 THEN k := SHORT(-e); x := 0.0
-      END;
-      x0 := Reals.Ten(SHORT(k+e)); x := x0*x + 0.5;
-      IF x >= 10.0*x0 THEN INC(e) END;
-      (*e = no. of digits before decimal point*)
-      INC(e); i := SHORT(k+e); Reals.Convert(x, i, d);
-      IF e > 0 THEN
-        seq(" ", SHORT(n-e-k-2)); Write(W, sign); dig(e);
-        Write(W, "."); dig(k)
-      ELSE seq(" ", SHORT(n-k-3));
-        Write(W, sign); Write(W, "0"); Write(W, ".");
-        seq("0", SHORT(-e)); dig(SHORT(k+e))
-      END
-    END
-  END WriteRealFix;
-
-  PROCEDURE WriteRealHex* (VAR W: Writer; x: REAL);
-    VAR i: INTEGER;
-      d: ARRAY 8 OF CHAR;
-  BEGIN Reals.ConvertH(x, d); i := 0;
-    REPEAT Write(W, d[i]); INC(i) UNTIL i = 8
-  END WriteRealHex;
-
-  PROCEDURE WriteLongReal* (VAR W: Writer; x: LONGREAL; n: INTEGER);
-    VAR ch: CHAR; i: INTEGER; dotzero: BOOLEAN;
-      d: ARRAY 28 OF CHAR;
-  BEGIN
-    Reals.RealToStr(x, n, d);
-    i := 0; ch := d[0]; dotzero := TRUE;
-    WHILE (ch # 0X) & (ch # "E") DO
-      IF (ch = ".") OR (ch > "9") THEN dotzero := FALSE END; (* NaN, -INF/+INF *)
-      Write(W, ch); INC(i); ch := d[i]
-    END;
-    IF ch = "E" THEN
-      Write(W, "E"); INC(i); ch := d[i];
-      IF (ch = "+") OR (ch = "-") THEN Write(W, ch); INC(i); ch := d[i] END;
-      IF ch = "0" THEN INC(i); ch := d[i];
-        IF ch = "0" THEN INC(i); ch := d[i] END
-      END;
-      WHILE ch # 0X DO Write(W, ch); INC(i); ch := d[i] END
-    ELSIF dotzero THEN
-      Write(W, "."); Write(W, "0")
-    END
-  END WriteLongReal;
-
-  PROCEDURE WriteLongRealHex* (VAR W: Writer; x: LONGREAL);
-    VAR i: INTEGER;
-      d: ARRAY 16 OF CHAR;
-  BEGIN Reals.ConvertHL(x, d); i := 0;
-    REPEAT Write(W, d[i]); INC(i) UNTIL i = 16
-  END WriteLongRealHex;
-
-  PROCEDURE WriteDate* (VAR W: Writer; t, d: LONGINT);
-
-    PROCEDURE WritePair(ch: CHAR; x: LONGINT);
-    BEGIN Write(W, ch);
-      Write(W, SHORT(CHR(x DIV 10 + 30H))); Write(W, SHORT(CHR(x MOD 10 + 30H)))
-    END WritePair;
-
-  BEGIN
-    WritePair(" ", d MOD 32); WritePair(".", d DIV 32 MOD 16); WritePair(".", d DIV 512 MOD 128);
-    WritePair(" ", t DIV 4096 MOD 32); WritePair(":", t DIV 64 MOD 64); WritePair(":", t MOD 64)
-  END WriteDate;
-
-
-  (** Text Filing **)
-
-  PROCEDURE Load0 (VAR r: Files.Rider; T: Text);
-    VAR u, un: Run; p: Piece; e: Elem;
-      org, pos, hlen, plen: LONGINT; ecnt, fno, fcnt, col, voff: SHORTINT;
-      f: Files.File;
-      msg: FileMsg;
-      mods, procs: ARRAY 64, 32 OF CHAR;
-      name: ARRAY 32 OF CHAR;
-      fnts: ARRAY 32 OF FontsFont;
-
-    PROCEDURE LoadElem (VAR r: Files.Rider; pos, span: LONGINT; VAR e: Elem);
-      VAR M: Modules.Module; Cmd: Modules.Command; a: Alien;
-        org, ew, eh: LONGINT; eno: SHORTINT;
-    BEGIN new := NIL;
-      Files.ReadInt(r, ew); Files.ReadInt(r, eh); Files.ReadByte(r, eno);
-      IF eno > ecnt THEN ecnt := eno; Files.ReadString(r, mods[eno]); Files.ReadString(r, procs[eno]) END;
-      org := SHORT(Files.Pos(r)); M := Modules.ThisMod(mods[eno]);
-      IF M # NIL THEN Cmd := Modules.ThisCommand(M, procs[eno]);
-        IF Cmd # NIL THEN Cmd END
-      END;
-      e := new;
-      IF e # NIL THEN e.W := ew; e.H := eh; e.base := T;
-        msg.pos := pos; e.handle(e, msg);
-        IF SHORT(Files.Pos(r)) # org + span THEN e := NIL END
-      END;
-      IF e = NIL THEN Files.Set(r, f, org + span);
-        NEW(a); a.W := ew; a.H := eh; a.handle := HandleAlien; a.base := T;
-        a.file := f; a.org := org; a.span := span;
-        a.mod := mods[eno]$; a.proc := procs[eno]$;
-        e := a
-      END
-    END LoadElem;
-
-  BEGIN pos := SHORT(Files.Pos(r)); f := Files.Base(r);
-    NEW(u); u.len := MAX(LONGINT); (*u.fnt := FontsDefault;*)u.fnt := NIL; u.col := Displaywhite;
-    T.head := u; ecnt := 0; fcnt := 0;
-    msg.id := load; msg.r := r;
-    Files.ReadInt(msg.r, hlen); (*!!!org := pos + hlen;*) org := pos -2 + hlen; pos := org; Files.ReadByte(msg.r, fno);
-    WHILE fno # 0 DO
-      IF fno > fcnt THEN fcnt := fno; Files.ReadString(msg.r, name); fnts[fno] := FontsThis(name) END;
-      Files.ReadByte(msg.r, col); Files.ReadByte(msg.r, voff); Files.ReadInt(msg.r, plen);
-      IF plen > 0 THEN NEW(p); p.file := f; p.org := pos; p.ascii := FALSE; un := p; un.len := plen
-      ELSE LoadElem(msg.r, pos - org, -plen, e); un := e; un.len := 1
-      END;
-      (*un.fnt := fnts[fno];*) un.col := col; un.voff := voff;
-      INC(pos, un.len); u.next := un; un.prev := u; u := un; Files.ReadByte(msg.r, fno)
-    END;
-    u.next := T.head; T.head.prev := u; T.cache := T.head; T.corg := 0;
-    Files.ReadInt(msg.r, T.len); Files.Set(r, f, SHORT(Files.Pos(msg.r)) + T.len)
-  END Load0;
-
-  PROCEDURE Load* (VAR r: Files.Rider; T: Text);
-    CONST oldTag = -4095;
-    VAR tag: INTEGER;
-  BEGIN
-    (* for compatibility inner text tags are checked and skipped; remove this in a later version *)
-    Files.ReadSInt(r, tag); IF tag # oldTag THEN Files.Set(r, Files.Base(r), Files.Pos(r)-2) END;
-    Load0(r, T)
-  END Load;
-
-  PROCEDURE Open* (T: Text; IN name: ARRAY OF CHAR);
-    VAR f: Files.File; r: Files.Rider; u: Run; p: Piece; tag, version, bom: CHAR; hlen: LONGINT;
-  BEGIN f := Files.Old(name);
-    IF f = NIL THEN f := Files.New("") END;
-    Files.Set(r, f, 0); Files.ReadChar(r, tag); Files.ReadChar(r, version);
-    IF (tag = textTag) OR (tag = 01X) & (version = textTag) THEN Load0(r, T)
-    ELSE (*ascii*)
-      NEW(u); u.len := MAX(LONGINT); u.fnt := NIL; u.col := Displaywhite;
-      NEW(p);
-      IF (tag = DocBlockId) & (version = 07X) THEN (* extract ascii text from System 3 text document *)
-        Files.Set(r, f, 28); Files.ReadInt(r, hlen);
-        Files.Set(r, f, 22 + hlen); Files.ReadInt(r, T.len); p.org := 26 + hlen
-      ELSE
-        T.len := SHORT(Files.Length(f));
-        (* checking isn't it UTF-8 encoded text with BOM? *)
-        Files.ReadChar(r, bom);
-        IF (tag = 0EFX) & (version = 0BBX) & (bom = 0BFX) THEN p.org := 3
-        ELSE p.org := 0
-        END;
-      END ;
-      IF T.len > 0 THEN p.len := T.len; p.fnt := FontsDefault;
-        p.col := Displaywhite; p.voff := 0; p.file := f; p.ascii := TRUE;
-        u.next := p; u.prev := p; p.next := u; p.prev := u
-      ELSE u.next := u; u.prev := u
-      END;
-      T.head := u; T.cache := T.head; T.corg := 0
-    END
-  END Open;
-
-  PROCEDURE Store* (VAR r: Files.Rider; T: Text);
-    VAR r1: Files.Rider; u, un: Run; e: Elem; org, pos, delta, hlen, rlen: LONGINT; ecnt, fno, fcnt: SHORTINT; ch: CHAR;  (* << *)
-      msg: FileMsg; iden: IdentifyMsg;
-      mods, procs: ARRAY 64, 32 OF CHAR;
-      fnts: ARRAY 32 OF FontsFont;
-      block: ARRAY 1024 OF CHAR;
-
-    PROCEDURE StoreElem (VAR r: Files.Rider; pos: LONGINT; e: Elem);
-      VAR r1: Files.Rider; org, span: LONGINT; eno: SHORTINT;
-    BEGIN mods[ecnt] := iden.mod$; procs[ecnt] := iden.proc$; eno := 1;
-      WHILE (mods[eno] # iden.mod) OR (procs[eno] # iden.proc) DO INC(eno) END;
-      Files.Set(r1, Files.Base(r), Files.Pos(r));
-      Files.WriteInt(r, 0); Files.WriteInt(r, 0); Files.WriteInt(r, 0); (*fixup slot*)
-      Files.WriteByte(r, eno);
-      IF eno = ecnt THEN INC(ecnt); Files.WriteString(r, iden.mod); Files.WriteString(r, iden.proc) END;
-      msg.pos := pos; org := SHORT(Files.Pos(r)); e.handle(e, msg); span := SHORT(Files.Pos(r)) - org;
-      Files.WriteInt(r1, -span); Files.WriteInt(r1, e.W); Files.WriteInt(r1, e.H) (*fixup*)
-    END StoreElem;
-
-  BEGIN
-    org := SHORT(Files.Pos(r)); msg.id := store; msg.r := r; Files.WriteInt(msg.r, 0); (*fixup slot*)
-    u := T.head.next; pos := 0; delta := 0; fcnt := 1; ecnt := 1;
-    WHILE u # T.head DO
-      IF u IS Elem THEN iden.mod[0] := 0X; u(Elem).handle(u(Elem), iden) ELSE iden.mod[0] := 1X END;
-      IF iden.mod[0] # 0X THEN
-        fnts[fcnt] := u.fnt; fno := 1;
-        WHILE fnts[fno].name # u.fnt.name DO INC(fno) END;
-        Files.WriteByte(msg.r, fno);
-        IF fno = fcnt THEN INC(fcnt); Files.WriteString(msg.r, u.fnt.name) END;
-        Files.WriteByte(msg.r, u.col); Files.WriteByte(msg.r, u.voff)
-      END;
-      IF u IS Piece THEN rlen := u.len; un := u.next;
-        WHILE (un IS Piece) & (un.fnt = u.fnt) & (un.col = u.col) & (un.voff = u.voff) DO
-          INC(rlen, un.len); un := un.next
-        END;
-        Files.WriteInt(msg.r, rlen); INC(pos, rlen); u := un
-      ELSIF iden.mod[0] # 0X THEN StoreElem(msg.r, pos, u(Elem)); INC(pos); u := u.next
-      ELSE INC(delta); u := u.next
-      END
-    END;
-    Files.WriteByte(msg.r, 0); Files.WriteInt(msg.r, T.len - delta);
-    (*!!!hlen := Files.Pos(msg.r) - org;*) hlen := SHORT(Files.Pos(msg.r)) - org + 2;
-    Files.Set(r1, Files.Base(msg.r), org); Files.WriteInt(r1, hlen); (*fixup*)
-    u := T.head.next;
-    WHILE u # T.head DO
-      IF u IS Piece THEN
-        WITH u: Piece DO
-          IF u.ascii THEN Files.Set(r1, u.file, u.org); delta := u.len;  (* << LF to CR *)
-            WHILE delta > 0 DO Files.ReadChar(r1, ch); DEC(delta);
-              IF ch = 0AX THEN Files.WriteChar(msg.r, CR) ELSE Files.WriteChar(msg.r, ch) END
-            END
-          ELSE Files.Set(r1, u.file, u.org); delta := u.len;
-            WHILE delta > LEN(block) DO
-              Files.ReadBytes(r1, s.THISARR(s.ADR(block), LEN(block)), LEN(block));
-              Files.WriteBytes(msg.r, s.THISARR(s.ADR(block), LEN(block)), LEN(block));
-              DEC(delta, LEN(block))
-            END;
-            Files.ReadBytes(r1, s.THISARR(s.ADR(block), LEN(block)), delta);
-            Files.WriteBytes(msg.r, s.THISARR(s.ADR(block), LEN(block)), delta)
-          END
-        END
-      ELSE iden.mod[0] := 0X; u(Elem).handle(u(Elem), iden);
-        IF iden.mod[0] # 0X THEN Files.WriteChar(msg.r, ElemChar) END
-      END;
-      u := u.next
-    END;
-    r := msg.r;
-    IF T.notify # NIL THEN T.notify(T, unmark, 0, 0) END
-  END Store;
-
-  PROCEDURE Close* (T: Text; IN name: ARRAY OF CHAR);
-    VAR f: Files.File; r: Files.Rider; i, res: LONGINT; bak: ARRAY 64 OF CHAR;
-  BEGIN
-    f := Files.New(name); Files.Set(r, f, 0); Files.WriteChar(r, textTag); Files.WriteChar(r, version); Store(r, T);
-    i := 0; WHILE name[i] # 0X DO INC(i) END;
-    bak := name$; bak[i] := "."; bak[i+1] := "B"; bak[i+2] := "a"; bak[i+3] := "k"; bak[i+4] := 0X;
-    Files.Rename(name, bak, res); Files.Register(f)
-  END Close;
-
-BEGIN del := NIL; NEW(FontsDefault); FontsDefault.name := "Syntax10.Scn.Fnt"
-END Texts.