CU Amiga Super CD-ROM 11/CU Amiga Magazine's Super CD-ROM 11 (1997)(EMAP Images)(GB)(Track 1 of 3)[!][issue 1997-06].iso/cucd/programming/oberonv4/source/system/texts.mod

Oberon Text | 1996-08-11 | 31KB | 802 lines

Syntax10.Scn.Fnt
Syntax10b.Scn.Fnt
FoldElems
ParcElems
Alloc
MODULE Texts;    (* Copyright (c) ETH Z
rich, 1989-96 / jg, nw, cas, hm, rc 23.9.93 *)
    See, and update if necessary the history at the bottom of the file.
IMPORT
    HostSYS
    ,Display,Files,Fonts,Modules,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; textVersion=01X;
        A run is either a piece or an elem.
        The runs are enchained into a doubly linked list with a sentinel element,
        to form the whole text.
        It is not clear, if the sentinel needs to have len=MAX(LONGINT), or if the
        length is ignored.
    Run = POINTER TO RunDesc;
    RunDesc = RECORD
        prev, next: Run;
        len: LONGINT;    (* length of this run *)
        fnt: Fonts.Font;
        col, voff: SHORTINT;
        host: BOOLEAN    (* remeber whether file was Oberon Text or host text *)
    END;
        The storage for a piece is always supplied by a file, either the file where
        the Text came from, or a temporary file.
    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);
        base    points to the text which contains this element.
    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;
        Why aren't mod and proc types exported from Modules ???
    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);
        head points to the sentinel.
    TextDesc* = RECORD
        len*: LONGINT;
        notify*: Notifier;
        head,cache: Run;
        corg: LONGINT
    END;
    Reader* = RECORD
        eot*: BOOLEAN;
        fnt*: Fonts.Font;
        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*: INTEGER;
        s*: ARRAY 512 OF CHAR;
    END;
    Writer* = RECORD
        buf*: Buffer;
        fnt*: Fonts.Font;
        col*, voff*: SHORTINT;
        rider: Files.Rider;
        file: Files.File
    END;
        Why aren't mod and proc types exported from Modules ???
    Alien = POINTER TO RECORD (ElemDesc)
        file: Files.File;
        org, span: LONGINT;
        mod, proc: ARRAY 32 OF CHAR
    END;
    isNameChar-:PROCEDURE(ch:CHAR):BOOLEAN;
    isNameChar1-:PROCEDURE(ch:CHAR):BOOLEAN;
    new*: Elem;
    del: Buffer;
(* run primitives *)
PROCEDURE Find (T: Text; VAR pos: LONGINT; VAR u: Run; VAR org, off: LONGINT); (*
    Return the run which contains character/element at position pos.
    off    Position within the run.
    org    Position of start of run within Text.
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 Find;
PROCEDURE Split (off: LONGINT; VAR u, un: Run); (*
    Split piece at relative posisiont off.
    un    points to piece starting at the split point.
    u    points to piece preceeding un.
    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.host := u.host; p.prev := U; p.next := U.next; p.next.prev := p; U.next := p;
END Split;
PROCEDURE Merge (T:Text; u:Run; VAR v:Run); (*
    Merge two pieces, if they are adjacent, use the same file for storage
    and have the same attributes.
    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).host = v(Piece).host) 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 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 Splice;
PROCEDURE ClonePiece (p: Piece): Piece;
    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
                (*
                    Is it a good idea to abuse the last element of the name
                    to mark an alien ???
                    Windows Oberon doesn't do that.
                *)
                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 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; 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;
    Display.Synchronize;
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;
    Display.Synchronize;
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: Fonts.Font; 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 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;
    IF u(Piece).host THEN ch:=HostSYS.toOberon(ch); END;    (* << Unix: LF to CR *)
    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 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 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 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  (BM 1992.1.1): (-1)^s * 1.m * 2^(e-e0), where
    s    e    e0    m
REAL    1-bit    8-bit biased    127    1+23-bit explicit
LONGREAL    1-bit    11-bit biased    1023    1+52-bit explicit
PROCEDURE Scan* (VAR S: Scanner);
    CONST maxD = 256;
    VAR ch: 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 HostSYS.IsNameChar1(ch) THEN (*name*)
        REPEAT S.s[i] := ch; INC(i); Read(S, ch)
        UNTIL ~HostSYS.IsNameChar(ch) OR (i = LEN(S.s)-1);
        S.s[i] := 0X; S.len := i; S.class := Name;
    ELSIF ch = 22X THEN (*literal string*)
        Read(S, ch);
        WHILE (ch # 22X) & (ch >= " ") & (i # LEN(S.s)-1) DO    (* << Unix *)
            S.s[i] := ch; INC(i); Read(S, ch)
        END;
        S.s[i] := 0X; S.len := i; Read(S, ch); S.class := String;
    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 := Int;
                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 := LongReal; S.x := x
                END ;
                IF hex THEN S.class := Inval END
            ELSE (*decimal integer*)
                S.class := Int; 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 := Int END
            END
        ELSE S.class := Char;
            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.voff := 0;
    W.file := Files.New(""); Files.Set(W.rider, W.file, 0)
END OpenWriter;
PROCEDURE SetFont* (VAR W: Writer; fnt: Fonts.Font);
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)
    & ~u(Piece).host 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; p.host := FALSE
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 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 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 = 40;
    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 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 Fonts.Font;
    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;
    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) 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; p.host := 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.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);
    fixedFont:Fonts.Font;
    f:Files.File;
    r:Files.Rider;
    u:Run;
    p:Piece;
    tag,version: CHAR;
BEGIN
    f := Files.Old(name);
    IF f = NIL THEN                        (* 17.2.95 mah do not read (buffer allocated) when opening new file *)
        f := Files.New(""); tag := 0X
    ELSE
        Files.Set(r, f, 0); Files.Read(r, tag); Files.Read(r, version)
    END;
    IF (tag=textTag) & (version=textVersion) THEN
        Load0(r,T);
    ELSE
            Not an Oberon Text file.
        fixedFont:=Fonts.This("Courier10.Scn.Fnt");
        NEW(u); u.len := MAX(LONGINT); u.fnt := NIL; u.col := Display.white;
        T.len := Files.Length(f);
        IF T.len > 0 THEN
            NEW(p); p.len := T.len; p.fnt := fixedFont;
            p.col := Display.white; p.voff := 0; p.file := f; p.org := 0; p.host := 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 Open;
PROCEDURE Store* (VAR r: Files.Rider; T: Text);
    VAR r1: Files.Rider; u, un: Run; 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 Fonts.Font;
        block: ARRAY 1024 OF CHAR;
    PROCEDURE StoreElem (VAR r: Files.Rider; pos: LONGINT; e: Elem);
        Windows StoreElem stores elem Width and Height before sending the
        FileMsg. This makes a difference, if a handler changes W and H when
        it receives the FileMsg. Is this allowed?
        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
                IF u.host THEN Files.Set(r1, u.file, u.org); delta := u.len;
                    WHILE delta > 0 DO Files.Read(r1, ch); DEC(delta);
                        Files.Write(msg.r, HostSYS.toOberon(ch));
                    END
                ELSE 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
            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 512 OF CHAR;
BEGIN
    f := Files.New(name); Files.Set(r, f, 0); Files.Write(r, textTag); Files.Write(r,textVersion); 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;
    isNameChar1:=HostSYS.IsNameChar1;
    isNameChar:=HostSYS.IsNameChar;
END Texts.
Date    Author    Modification
1996-07-31    [e-mail]    First unified version.