From d4878eaf0861679d6af935c2078ab43cf59dcf67 Mon Sep 17 00:00:00 2001
From: DeaDDooMER <deaddoomer@deadsoftware.ru>
Date: Fri, 15 Sep 2017 20:25:44 +0300
Subject: [PATCH] =?utf8?q?=D0=9F=D0=BE=D0=BF=D1=80=D0=B0=D0=BB=D0=B5=D0=BD?=
 =?utf8?q?=D1=8B=20=D0=BE=D0=B1=D1=80=D0=B0=D1=89=D0=B5=D0=BD=D0=B8=D1=8F?=
 =?utf8?q?=20=D0=BA=20NIL?=
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit

---
 rtl/Texts.obn | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rtl/Texts.obn b/rtl/Texts.obn
index ba4d6cd..b6fe9c0 100644
--- a/rtl/Texts.obn
+++ b/rtl/Texts.obn
@@ -1 +1 @@
-MODULE Texts;	(** CAS/HM 7.10.93 -- interface based on Texts by JG/NW 6.12.91**)
	(* Ported from Oberon V4 -- this version not depended on graphics *)

	IMPORT
		Files, Reals;

	(*--- insert field e: Elem into Texts.Scanner and change Texts.Scan to set it in case of class=6 *)


	CONST
		ElemChar* = 1CX;
		TAB = 9X; CR = 0DX; maxD = 9;
		(**FileMsg.id**)
			load* = 0; store* = 1;
		(**Notifier op**)
			replace* = 0; insert* = 1; delete* = 2;
		(**Scanner.class**)
			Inval* = 0; Name* = 1; String* = 2; Int* = 3; Real* = 4; LongReal* = 5; Char* = 6;

		textTag = 0F0X; version = 01X;

	TYPE
		FontsFont = POINTER TO FontDesc;
		FontDesc = RECORD
			name: ARRAY 32 OF CHAR;
		END;

		Run = POINTER TO RunDesc;
		RunDesc = RECORD
			prev, next: Run;
			len: LONGINT;
			fnt: FontsFont;
			col, voff: SHORTINT
		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* = RECORD END;
		Handler* = PROCEDURE (e: Elem; VAR msg: ElemMsg);

		ElemDesc* = 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* = 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 32 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;


	(* 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.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) 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
					COPY(E.mod, msg.mod); COPY(E.proc, msg.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.Read(r, ch); Files.Write(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;
		T.notify(T, insert, pos, pos + len)
	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;
		T.notify(T, insert, pos, pos + len)
	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);
		T.notify(T, delete, beg, 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;
		T.notify(T, replace, beg, 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 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; VAR ch: CHAR);
		VAR u: Run;
	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.Read(R.rider, ch); R.elem := NIL
		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 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 := 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") THEN (*name*)
			REPEAT S.s[i] := ch; INC(i); Read(S, ch)
			UNTIL (CAP(ch) > "Z")
				OR ("A" > CAP(ch)) & (ch > "9")
				OR ("0" > ch) & (ch # ".")
				OR (i = 31);
			S.s[i] := 0X; S.len := i; S.class := 1
		ELSIF ch = 22X THEN (*literal string*)
			Read(S, ch);
			WHILE (ch # 22X) & (ch >= " ") & (i # 31) DO
				S.s[i] := ch; INC(i); Read(S, ch)
			END;
			S.s[i] := 0X; S.len := i; 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 := CHR(ORD(ch)-7)
						ELSIF ("a" <= ch) & (ch <= "f") THEN hex := TRUE; ch := 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 := 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 := Fonts.Default; W.col := Display.white; *)
		W.fnt := NIL; W.col := 0; 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.Write(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) 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 := Files.Length(W.file) - 1
		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; 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 11 OF CHAR;
	BEGIN i := 0;
		IF x < 0 THEN
			IF x = MIN(LONGINT) THEN WriteString(W, " -2147483648"); RETURN
			ELSE DEC(n); x0 := -x
			END
		ELSE x0 := x
		END;
		REPEAT
			a[i] := 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 WriteHex* (VAR W: Writer; x: LONGINT);
		VAR i: INTEGER; y: LONGINT;
			a: ARRAY 10 OF CHAR;
	BEGIN i := 0; Write(W, " ");
		REPEAT y := x MOD 10H;
			IF y < 10 THEN a[i] := CHR(y + 30H) ELSE a[i] := 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 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");
			REPEAT Write(W, " "); DEC(n) UNTIL n <= 3
		ELSIF e = 255 THEN
			WriteString(W, " NaN");
			WHILE n > 4 DO Write(W, " "); DEC(n) END
		ELSE
			IF n <= 9 THEN n := 3 ELSE DEC(n, 6) END;
			REPEAT Write(W, " "); DEC(n) UNTIL n <= 8;
			(*there are 2 < n <= 8 digits to be written*)
			IF x < 0.0 THEN Write(W, "-"); x := -x ELSE Write(W, " ") END;
			e := (e - 127) * 77  DIV 256;
			IF e >= 0 THEN x := x / Reals.Ten(e) ELSE x := Reals.Ten(-e) * x END;
			IF x >= 10.0 THEN x := 0.1*x; INC(e) END;
			x0 := Reals.Ten(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, "-"); e := -e ELSE Write(W, "+") END;
			Write(W, CHR(e DIV 10 + 30H)); Write(W, CHR(e MOD 10 + 30H))
		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(" ", n-k-2); Write(W, "0"); seq(" ", k+1)
		ELSIF e = 255 THEN WriteString(W, " NaN"); seq(" ", n-4)
		ELSE e := (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(-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 := maxD-1-e
				ELSIF k+e < 0 THEN k := -e; x := 0.0
			END;
			x0 := Reals.Ten(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 := k+e; Reals.Convert(x, i, d);
			IF e > 0 THEN
				seq(" ", n-e-k-2); Write(W, sign); dig(e);
				Write(W, "."); dig(k)
			ELSE seq(" ", n-k-3);
				Write(W, sign); Write(W, "0"); Write(W, ".");
				seq("0", -e); dig(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);
		CONST maxD = 16;
		VAR e: INTEGER; x0: LONGREAL;
			d: ARRAY maxD OF CHAR;
	BEGIN e := Reals.ExpoL(x);
		IF e = 0 THEN
			WriteString(W, "  0");
			REPEAT Write(W, " "); DEC(n) UNTIL n <= 3
		ELSIF e = 2047 THEN
			WriteString(W, " NaN");
			WHILE n > 4 DO Write(W, " "); DEC(n) END
		ELSE
			IF n <= 10 THEN n := 3 ELSE DEC(n, 7) END;
			REPEAT Write(W, " "); DEC(n) UNTIL n <= maxD;
			(*there are 2 <= n <= maxD digits to be written*)
			IF x < 0 THEN Write(W, "-"); x := -x ELSE Write(W, " ") END;
			e := SHORT(LONG(e - 1023) * 77 DIV 256);
			IF e >= 0 THEN x := x / Reals.TenL(e) ELSE x := Reals.TenL(-e) * x END ;
			IF x >= 10.0D0 THEN x := 0.1D0 * x; INC(e) END ;
			x0 := Reals.TenL(n-1); x := x0*x + 0.5D0;
			IF x >= 10.0D0*x0 THEN x := 0.1D0 * x; INC(e) END ;
			Reals.ConvertL(x, n, d);
			DEC(n); Write(W, d[n]); Write(W, ".");
			REPEAT DEC(n); Write(W, d[n]) UNTIL n = 0;
			Write(W, "D");
			IF e < 0 THEN Write(W, "-"); e := -e ELSE Write(W, "+") END;
			Write(W, CHR(e DIV 100 + 30H)); e := e MOD 100;
			Write(W, CHR(e DIV 10 + 30H));
			Write(W, CHR(e MOD 10 + 30H))
		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, CHR(x DIV 10 + 30H)); Write(W, 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.ReadLInt(r, ew); Files.ReadLInt(r, eh); Files.Read(r, eno);
			IF eno > ecnt THEN ecnt := eno; Files.ReadString(r, mods[eno]); Files.ReadString(r, procs[eno]) END;
			org := 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 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;
				COPY(mods[eno], a.mod); COPY(procs[eno], a.proc);
				e := a
			END
		END LoadElem;

	BEGIN pos := Files.Pos(r); f := Files.Base(r);
		NEW(u); u.len := MAX(LONGINT); (*u.fnt := Fonts.Default;*)u.fnt := NIL; (*u.col := Display.white;*) u.col := 0;
		T.head := u; ecnt := 0; fcnt := 0;
		msg.id := load; msg.r := r;
		Files.ReadLInt(msg.r, hlen); (*!!!org := pos + hlen;*) org := pos -2 + hlen; pos := org; Files.Read(msg.r, fno);
		WHILE fno # 0 DO
			IF fno > fcnt THEN fcnt := fno; Files.ReadString(msg.r, name); (* fnts[fno] := Fonts.This(name) *) fnts[fno] := NIL END;
			Files.Read(msg.r, col); Files.Read(msg.r, voff); Files.ReadLInt(msg.r, plen);
			IF plen > 0 THEN NEW(p); p.file := f; p.org := pos; 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.Read(msg.r, fno)
		END;
		u.next := T.head; T.head.prev := u; T.cache := T.head; T.corg := 0;
		Files.ReadLInt(msg.r, T.len); Files.Set(r, f, 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.ReadInt(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; name: ARRAY OF CHAR);
		VAR f: Files.File; r: Files.Rider; u: Run; p: Piece; tag, version: CHAR;
	BEGIN f := Files.Old(name);
		IF f = NIL THEN f := Files.New("") END;
		Files.Set(r, f, 0); Files.Read(r, tag); Files.Read(r, version);
		IF (tag = textTag) OR (tag = 01X) & (version = textTag) THEN Load0(r, T)
		ELSE NEW(u); u.len := MAX(LONGINT); u.fnt := NIL; (* u.col := Display.white; *) u.col := 0;
			T.len := Files.Length(f);
			IF T.len > 0 THEN NEW(p); p.len := T.len; (* p.fnt := Fonts.Default; *) p.fnt := NIL;
				(* p.col := Display.white; *) p.col := 0; p.voff := 0; p.file := f; p.org := 0;
				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;
			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 COPY(iden.mod, mods[ecnt]); COPY(iden.proc, procs[ecnt]); 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.WriteLInt(r, 0); Files.WriteLInt(r, 0); Files.WriteLInt(r, 0); (*fixup slot*)
			Files.Write(r, eno);
			IF eno = ecnt THEN INC(ecnt); Files.WriteString(r, iden.mod); Files.WriteString(r, iden.proc) END;
			msg.pos := pos; org := Files.Pos(r); e.handle(e, msg); span := Files.Pos(r) - org;
			Files.WriteLInt(r1, -span); Files.WriteLInt(r1, e.W); Files.WriteLInt(r1, e.H) (*fixup*)
		END StoreElem;

	BEGIN
		org := Files.Pos(r); msg.id := store; msg.r := r; Files.WriteLInt(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.Write(msg.r, fno);
				IF fno = fcnt THEN INC(fcnt); Files.WriteString(msg.r, u.fnt.name) END;
				Files.Write(msg.r, u.col); Files.Write(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.WriteLInt(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.Write(msg.r, 0); Files.WriteLInt(msg.r, T.len - delta);
		(*!!!hlen := Files.Pos(msg.r) - org;*) hlen := Files.Pos(msg.r) - org + 2;
		Files.Set(r1, Files.Base(msg.r), org); Files.WriteLInt(r1, hlen); (*fixup*)
		u := T.head.next;
		WHILE u # T.head DO
			IF u IS Piece THEN
				WITH u: Piece DO Files.Set(r1, u.file, u.org); delta := u.len;
					WHILE delta > LEN(block) DO Files.ReadBytes(r1, block, LEN(block));
						Files.WriteBytes(msg.r, block, LEN(block)); DEC(delta, LEN(block))
					END;
					Files.ReadBytes(r1, block, delta); Files.WriteBytes(msg.r, block, delta)
				END
			ELSE iden.mod[0] := 0X; u(Elem).handle(u(Elem), iden);
				IF iden.mod[0] # 0X THEN Files.Write(msg.r, ElemChar) END
			END;
			u := u.next
		END;
		r := msg.r;
	END Store;
	
	PROCEDURE Close* (T: Text; name: ARRAY OF CHAR);
		VAR f: Files.File; r: Files.Rider; i, res: INTEGER; bak: ARRAY 64 OF CHAR;
	BEGIN
		f := Files.New(name); Files.Set(r, f, 0); Files.Write(r, textTag); Files.Write(r, version); Store(r, T);
		i := 0; WHILE name[i] # 0X DO INC(i) END;
		COPY(name, bak); 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
END Texts.
\ No newline at end of file
+MODULE Texts;	(** CAS/HM 7.10.93 -- interface based on Texts by JG/NW 6.12.91**)
	(* Ported from Oberon V4 -- this version not depended on graphics *)

	IMPORT
		Files, Reals;

	(*--- insert field e: Elem into Texts.Scanner and change Texts.Scan to set it in case of class=6 *)


	CONST
		ElemChar* = 1CX;
		TAB = 9X; CR = 0DX; maxD = 9;
		(**FileMsg.id**)
			load* = 0; store* = 1;
		(**Notifier op**)
			replace* = 0; insert* = 1; delete* = 2;
		(**Scanner.class**)
			Inval* = 0; Name* = 1; String* = 2; Int* = 3; Real* = 4; LongReal* = 5; Char* = 6;

		textTag = 0F0X; version = 01X;

		Displaywhite = 15;

	TYPE
		FontsFont = POINTER TO FontDesc;
		FontDesc = RECORD
			name: ARRAY 32 OF CHAR;
		END;

		Run = POINTER TO RunDesc;
		RunDesc = RECORD
			prev, next: Run;
			len: LONGINT;
			fnt: FontsFont;
			col, voff: SHORTINT
		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* = RECORD END;
		Handler* = PROCEDURE (e: Elem; VAR msg: ElemMsg);

		ElemDesc* = 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* = 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 32 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;


	(* 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.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) 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
					COPY(E.mod, msg.mod); COPY(E.proc, msg.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.Read(r, ch); Files.Write(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 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; VAR ch: CHAR);
		VAR u: Run;
	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.Read(R.rider, ch); R.elem := NIL
		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 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 := 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") THEN (*name*)
			REPEAT S.s[i] := ch; INC(i); Read(S, ch)
			UNTIL (CAP(ch) > "Z")
				OR ("A" > CAP(ch)) & (ch > "9")
				OR ("0" > ch) & (ch # ".")
				OR (i = 31);
			S.s[i] := 0X; S.len := i; S.class := 1
		ELSIF ch = 22X THEN (*literal string*)
			Read(S, ch);
			WHILE (ch # 22X) & (ch >= " ") & (i # 31) DO
				S.s[i] := ch; INC(i); Read(S, ch)
			END;
			S.s[i] := 0X; S.len := i; 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 := CHR(ORD(ch)-7)
						ELSIF ("a" <= ch) & (ch <= "f") THEN hex := TRUE; ch := 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 := 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.Write(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) 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 := Files.Length(W.file) - 1
		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; 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 11 OF CHAR;
	BEGIN i := 0;
		IF x < 0 THEN
			IF x = MIN(LONGINT) THEN WriteString(W, " -2147483648"); RETURN
			ELSE DEC(n); x0 := -x
			END
		ELSE x0 := x
		END;
		REPEAT
			a[i] := 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 WriteHex* (VAR W: Writer; x: LONGINT);
		VAR i: INTEGER; y: LONGINT;
			a: ARRAY 10 OF CHAR;
	BEGIN i := 0; Write(W, " ");
		REPEAT y := x MOD 10H;
			IF y < 10 THEN a[i] := CHR(y + 30H) ELSE a[i] := 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 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");
			REPEAT Write(W, " "); DEC(n) UNTIL n <= 3
		ELSIF e = 255 THEN
			WriteString(W, " NaN");
			WHILE n > 4 DO Write(W, " "); DEC(n) END
		ELSE
			IF n <= 9 THEN n := 3 ELSE DEC(n, 6) END;
			REPEAT Write(W, " "); DEC(n) UNTIL n <= 8;
			(*there are 2 < n <= 8 digits to be written*)
			IF x < 0.0 THEN Write(W, "-"); x := -x ELSE Write(W, " ") END;
			e := (e - 127) * 77  DIV 256;
			IF e >= 0 THEN x := x / Reals.Ten(e) ELSE x := Reals.Ten(-e) * x END;
			IF x >= 10.0 THEN x := 0.1*x; INC(e) END;
			x0 := Reals.Ten(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, "-"); e := -e ELSE Write(W, "+") END;
			Write(W, CHR(e DIV 10 + 30H)); Write(W, CHR(e MOD 10 + 30H))
		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(" ", n-k-2); Write(W, "0"); seq(" ", k+1)
		ELSIF e = 255 THEN WriteString(W, " NaN"); seq(" ", n-4)
		ELSE e := (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(-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 := maxD-1-e
				ELSIF k+e < 0 THEN k := -e; x := 0.0
			END;
			x0 := Reals.Ten(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 := k+e; Reals.Convert(x, i, d);
			IF e > 0 THEN
				seq(" ", n-e-k-2); Write(W, sign); dig(e);
				Write(W, "."); dig(k)
			ELSE seq(" ", n-k-3);
				Write(W, sign); Write(W, "0"); Write(W, ".");
				seq("0", -e); dig(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);
		CONST maxD = 16;
		VAR e: INTEGER; x0: LONGREAL;
			d: ARRAY maxD OF CHAR;
	BEGIN e := Reals.ExpoL(x);
		IF e = 0 THEN
			WriteString(W, "  0");
			REPEAT Write(W, " "); DEC(n) UNTIL n <= 3
		ELSIF e = 2047 THEN
			WriteString(W, " NaN");
			WHILE n > 4 DO Write(W, " "); DEC(n) END
		ELSE
			IF n <= 10 THEN n := 3 ELSE DEC(n, 7) END;
			REPEAT Write(W, " "); DEC(n) UNTIL n <= maxD;
			(*there are 2 <= n <= maxD digits to be written*)
			IF x < 0 THEN Write(W, "-"); x := -x ELSE Write(W, " ") END;
			e := SHORT(LONG(e - 1023) * 77 DIV 256);
			IF e >= 0 THEN x := x / Reals.TenL(e) ELSE x := Reals.TenL(-e) * x END ;
			IF x >= 10.0D0 THEN x := 0.1D0 * x; INC(e) END ;
			x0 := Reals.TenL(n-1); x := x0*x + 0.5D0;
			IF x >= 10.0D0*x0 THEN x := 0.1D0 * x; INC(e) END ;
			Reals.ConvertL(x, n, d);
			DEC(n); Write(W, d[n]); Write(W, ".");
			REPEAT DEC(n); Write(W, d[n]) UNTIL n = 0;
			Write(W, "D");
			IF e < 0 THEN Write(W, "-"); e := -e ELSE Write(W, "+") END;
			Write(W, CHR(e DIV 100 + 30H)); e := e MOD 100;
			Write(W, CHR(e DIV 10 + 30H));
			Write(W, CHR(e MOD 10 + 30H))
		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, CHR(x DIV 10 + 30H)); Write(W, 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.ReadLInt(r, ew); Files.ReadLInt(r, eh); Files.Read(r, eno);
			IF eno > ecnt THEN ecnt := eno; Files.ReadString(r, mods[eno]); Files.ReadString(r, procs[eno]) END;
			org := 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 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;
				COPY(mods[eno], a.mod); COPY(procs[eno], a.proc);
				e := a
			END
		END LoadElem;

	BEGIN pos := Files.Pos(r); f := Files.Base(r);
		NEW(u); u.len := MAX(LONGINT); u.fnt := FontsDefault; u.col := Displaywhite;
		T.head := u; ecnt := 0; fcnt := 0;
		msg.id := load; msg.r := r;
		Files.ReadLInt(msg.r, hlen); (*!!!org := pos + hlen;*) org := pos -2 + hlen; pos := org; Files.Read(msg.r, fno);
		WHILE fno # 0 DO
			IF fno > fcnt THEN fcnt := fno; Files.ReadString(msg.r, name); (* fnts[fno] := Fonts.This(name) *) fnts[fno] := NIL END;
			Files.Read(msg.r, col); Files.Read(msg.r, voff); Files.ReadLInt(msg.r, plen);
			IF plen > 0 THEN NEW(p); p.file := f; p.org := pos; 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.Read(msg.r, fno)
		END;
		u.next := T.head; T.head.prev := u; T.cache := T.head; T.corg := 0;
		Files.ReadLInt(msg.r, T.len); Files.Set(r, f, 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.ReadInt(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; name: ARRAY OF CHAR);
		VAR f: Files.File; r: Files.Rider; u: Run; p: Piece; tag, version: CHAR;
	BEGIN f := Files.Old(name);
		IF f = NIL THEN f := Files.New("") END;
		Files.Set(r, f, 0); Files.Read(r, tag); Files.Read(r, version);
		IF (tag = textTag) OR (tag = 01X) & (version = textTag) THEN Load0(r, T)
		ELSE NEW(u); u.len := MAX(LONGINT); u.fnt := NIL; u.col := Displaywhite;
			T.len := Files.Length(f);
			IF T.len > 0 THEN NEW(p); p.len := T.len; p.fnt := FontsDefault;
				p.col := Displaywhite; p.voff := 0; p.file := f; p.org := 0;
				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;
			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 COPY(iden.mod, mods[ecnt]); COPY(iden.proc, procs[ecnt]); 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.WriteLInt(r, 0); Files.WriteLInt(r, 0); Files.WriteLInt(r, 0); (*fixup slot*)
			Files.Write(r, eno);
			IF eno = ecnt THEN INC(ecnt); Files.WriteString(r, iden.mod); Files.WriteString(r, iden.proc) END;
			msg.pos := pos; org := Files.Pos(r); e.handle(e, msg); span := Files.Pos(r) - org;
			Files.WriteLInt(r1, -span); Files.WriteLInt(r1, e.W); Files.WriteLInt(r1, e.H) (*fixup*)
		END StoreElem;

	BEGIN
		org := Files.Pos(r); msg.id := store; msg.r := r; Files.WriteLInt(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.Write(msg.r, fno);
				IF fno = fcnt THEN INC(fcnt); Files.WriteString(msg.r, u.fnt.name) END;
				Files.Write(msg.r, u.col); Files.Write(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.WriteLInt(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.Write(msg.r, 0); Files.WriteLInt(msg.r, T.len - delta);
		(*!!!hlen := Files.Pos(msg.r) - org;*) hlen := Files.Pos(msg.r) - org + 2;
		Files.Set(r1, Files.Base(msg.r), org); Files.WriteLInt(r1, hlen); (*fixup*)
		u := T.head.next;
		WHILE u # T.head DO
			IF u IS Piece THEN
				WITH u: Piece DO Files.Set(r1, u.file, u.org); delta := u.len;
					WHILE delta > LEN(block) DO Files.ReadBytes(r1, block, LEN(block));
						Files.WriteBytes(msg.r, block, LEN(block)); DEC(delta, LEN(block))
					END;
					Files.ReadBytes(r1, block, delta); Files.WriteBytes(msg.r, block, delta)
				END
			ELSE iden.mod[0] := 0X; u(Elem).handle(u(Elem), iden);
				IF iden.mod[0] # 0X THEN Files.Write(msg.r, ElemChar) END
			END;
			u := u.next
		END;
		r := msg.r;
	END Store;
	
	PROCEDURE Close* (T: Text; name: ARRAY OF CHAR);
		VAR f: Files.File; r: Files.Rider; i, res: INTEGER; bak: ARRAY 64 OF CHAR;
	BEGIN
		f := Files.New(name); Files.Set(r, f, 0); Files.Write(r, textTag); Files.Write(r, version); Store(r, T);
		i := 0; WHILE name[i] # 0X DO INC(i) END;
		COPY(name, bak); 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);
END Texts.
\ No newline at end of file
-- 
2.29.2