Texts.Buffer, Texts.Writer (not finished)

Programs/TestWriter.Mod

@@ -0,0 +1,13 @@
+MODULE TestWriter;
+IMPORT Out, Texts;
+VAR
+  T: Texts.Text;
+  W: Texts.Writer;
+  R: Texts.Reader;
+BEGIN
+  NEW(T); Texts.Open(T, 'MYTEXT.TXT');
+  Texts.OpenWriter(W);
+  Texts.WriteString(W, 'HELLO'); Texts.WriteLn(W);
+  Texts.Append(T, W.buf);
+  Texts.Close(T)
+END TestWriter.

src/Texts.Mod

@@ -1,18 +1,21 @@
 MODULE Texts;
-IMPORT Files, SYSTEM;
+IMPORT Files, IntToStr := Int, Platform, SYSTEM;
 
 CONST
   (* Scanner class values *)
   Inval* = 0; Name* = 1; String* = 2; Int* = 3; Real* = 4;
   LongReal* = 5; Char* = 6;
 
+  isWindows = Platform.Windows;
+
 TYPE
   LONGINT* = SYSTEM.INT64;
 
   Text* = POINTER TO TextDesc;
   TextDesc* = RECORD
     len*: LONGINT;
-    F: Files.File
+    f: Files.File;
+    changed: BOOLEAN
   END;
 
   Reader* = RECORD
@@ -31,18 +34,29 @@ TYPE
     s*: ARRAY 1900 OF CHAR
   END;
 
+  Buffer* = POINTER TO BufDesc;
+  BufDesc* = RECORD
+    len*: LONGINT;
+    f: Files.File
+  END;
+
+  Writer* = RECORD
+    buf*: Buffer;
+    rider: Files.Rider
+  END;
+
 PROCEDURE Open*(T: Text; fname: ARRAY OF CHAR);
-BEGIN T.F := Files.Old(fname);
-  IF T.F = NIL THEN T.F := Files.New(fname) END;
-  T.len := Files.Length(T.F)
+BEGIN T.f := Files.Old(fname);
+  IF T.f = NIL THEN T.f := Files.New(fname) END;
+  T.len := Files.Length(T.f); T.changed := FALSE
 END Open;
 
 PROCEDURE Close*(T: Text);
-BEGIN IF T.F # NIL THEN Files.Register(T.F) END
+BEGIN IF (T.f # NIL) & T.changed THEN Files.Register(T.f) END
 END Close;
 
 PROCEDURE OpenReader*(VAR R: Reader; T: Text; pos: LONGINT);
-BEGIN Files.Set(R.rider, T.F, pos); R.eot := FALSE
+BEGIN Files.Set(R.rider, T.f, pos); R.eot := FALSE
 END OpenReader;
 
 PROCEDURE Read*(VAR R: Reader; VAR ch: CHAR);
@@ -62,6 +76,15 @@ PROCEDURE OpenScanner*(VAR S: Scanner; T: Text; pos: LONGINT);
 BEGIN OpenReader(S, T, pos); S.line := 0; S.nextCh := ' '
 END OpenScanner;
 
+PROCEDURE Ten(n: INTEGER): REAL;
+VAR t, p: REAL;
+BEGIN t := 1.0; p := 10.0; (* Compute 10^n *)
+  WHILE n > 0 DO
+    IF ODD(n) THEN t := p * t END;
+    p := p * p; n := n DIV 2
+  END ;
+RETURN t END Ten;
+
 PROCEDURE Scan*(VAR S: Scanner);
 VAR i, n: INTEGER;
   quot: CHAR;
@@ -104,17 +127,139 @@ BEGIN
   END
 END Scan;
 
-END Texts.
+PROCEDURE OpenBuf*(B: Buffer);
+BEGIN B.len := 0; B.f := Files.New('')
+END OpenBuf;
+
+PROCEDURE OpenWriter*(VAR W: Writer);
+BEGIN NEW(W.buf); OpenBuf(W.buf); Files.Set(W.rider, W.buf.f, 0)
+END OpenWriter;
+
+PROCEDURE Write*(VAR W: Writer; ch: CHAR);
+BEGIN Files.WriteChar(W.rider, ch); INC(W.buf.len)
+END Write;
+
+PROCEDURE WriteLn*(VAR W: Writer);
+BEGIN IF isWindows THEN Write(W, 0DX); Write(W, 0AX) ELSE Write(W, 0AX) END
+END WriteLn;
+
+PROCEDURE WriteString*(VAR W: Writer; s: ARRAY OF CHAR);
+VAR i: INTEGER;
+BEGIN i := 0;
+  WHILE s[i] # 0X DO Write(W, s[i]); INC(i) END
+END WriteString;
+
+PROCEDURE WriteInt*(VAR W: Writer; x, n: INTEGER);
+VAR i: INTEGER;
+  s: ARRAY 30 OF CHAR;
+BEGIN IntToStr.Str(x, s);
+  i := 0; WHILE s[i] # 0X DO INC(i) END;
+  DEC(n, i);
+  WHILE n > 0 DO Write(W, ' '); DEC(n) END;
+  WriteString(W, s)
+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;
 
-(*
-VAR T: Texts.Text;
-  S: Texts.Scanner;
+PROCEDURE WriteReal* (VAR W: Writer; x: REAL; n: INTEGER);
+VAR e, i, k, m: INTEGER;
+  d: ARRAY 16 OF CHAR;
+BEGIN e := ASR(SYSTEM.VAL(INTEGER, x), 23) MOD 100H;  (*binary exponent*)
+  IF e = 0 THEN
+    WriteString(W, '0');
+    WHILE n >= 3 DO Write(W, ' '); DEC(n) END
+  ELSIF e = 255 THEN WriteString(W, ' NaN ')
+  ELSE Write(W, ' ');
+    WHILE n >= 15 DO DEC(n); Write(W, ' ') END;
+    (* 2 < n < 9 digits to be written*)
+    IF x < 0.0 THEN Write(W, '-'); x := -x ELSE Write(W, ' ') END;
+    e := (e - 127) * 77 DIV 256 - 6;  (*decimal exponent*)
+    IF e >= 0 THEN x := x / Ten(e) ELSE x := Ten(-e) * x END;
+    m := FLOOR(x + 0.5);
+    IF m >= 10000000 THEN INC(e); m := m DIV 10 END;
+    i := 0; k := 13-n;
+    REPEAT
+       IF i = k THEN INC(m, 5) END;    (*rounding*)
+     d[i] := CHR(m MOD 10 + 30H); m := m DIV 10; INC(i)
+    UNTIL m = 0;
+    DEC(i); Write(W, d[i]); Write(W, '.');
+    IF i < n-7 THEN n := 0 ELSE n := 14 - n END;
+    WHILE i > n DO DEC(i); Write(W, d[i]) END;
+    Write(W, 'E'); INC(e, 6);
+     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 i, m: INTEGER; neg: BOOLEAN;
+  d: ARRAY 12 OF CHAR;
+BEGIN
+  IF x = 0.0 THEN WriteString(W, '0')
+  ELSE
+    IF x < 0.0 THEN x := -x; neg := TRUE ELSE neg := FALSE END;
+    IF k > 7 THEN k := 7 END;
+    x := Ten(k) * x; m := FLOOR(x + 0.5);
+    i := 0;
+    REPEAT d[i] := CHR(m MOD 10 + 30H); m := m DIV 10; INC(i) UNTIL m = 0;
+    Write(W, ' ');
+    WHILE n > i + 3 DO  Write(W, ' '); DEC(n) END;
+    IF neg THEN Write(W, '-'); DEC(n) ELSE Write(W, ' ') END;
+    WHILE i > k DO DEC(i); Write(W, d[i]) END;
+    Write(W, '.');
+    WHILE k > i DO DEC(k); Write(W, '0') END;
+    WHILE i > 0 DO DEC(i); Write(W, d[i]) END
+  END
+END WriteRealFix;
+
+PROCEDURE Save*(T: Text; beg, end: LONGINT; B: Buffer);
+VAR R, W: Files.Rider;
+  ch: CHAR;
 BEGIN
-  NEW(T);
-  Texts.Open(T, s);
-  Texts.OpenScanner(S, T, 0);
-  S.eot: BOOLEAN
-  Texts.Scan(S);
-  S.class = Texts.Int
-  S.i: INTEGER
-*)
+  IF end > T.len THEN end := T.len END;
+  Files.Set(R, T.f, beg); Files.Set(W, B.f, B.len);
+  DEC(end, beg);
+  WHILE end > 0 DO Files.ReadChar(R, ch); Files.WriteChar(W, ch) END;
+  INC(B.len, end - beg)
+END Save;
+
+PROCEDURE Copy*(SB, DB: Buffer);
+VAR R, W: Files.Rider;
+  ch: CHAR;
+BEGIN Files.Set(R, SB.f, 0); Files.Set(W, DB.f, DB.len);
+  Files.ReadChar(R, ch);
+  WHILE ~R.eof DO Files.WriteChar(W, ch); Files.ReadChar(R, ch) END;
+  INC(DB.len, SB.len)
+END Copy;
+
+PROCEDURE Insert*(T: Text; pos: LONGINT; B: Buffer);
+VAR R, W: Files.Rider;
+  ch: CHAR;
+  n, q: LONGINT;
+BEGIN n := T.len - pos;
+  IF n > 0 THEN q := B.len - n;
+    IF q > 0 THEN Files.Set(W, T.f, T.len);
+      WHILE q # 0 DO Files.WriteChar(W, ' '); DEC(q) END
+    END;
+    Files.Set(R, T.f, pos); Files.Set(W, T.f, pos + B.len);
+    WHILE n > 0 DO Files.ReadChar(R, ch); Files.WriteChar(W, ch) END
+  END;
+  n := B.len; Files.Set(R, B.f, 0); Files.Set(W, T.f, pos);
+  WHILE n # 0 DO Files.ReadChar(R, ch); Files.WriteChar(W, ch) END;
+  INC(T.len, B.len); T.changed := TRUE
+END Insert;
+
+PROCEDURE Append*(T: Text; B: Buffer);
+BEGIN Insert(T, T.len, B)
+END Append;
+
+END Texts.