438 lines
9 KiB
Modula-2
438 lines
9 KiB
Modula-2
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(*
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(c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
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See the copyright notice in the ACK home directory, in the file "Copyright".
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*)
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(*$R-*)
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IMPLEMENTATION MODULE PascalIO;
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(*
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Module: Pascal-like Input/Output
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Author: Ceriel J.H. Jacobs
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Version: $Header$
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*)
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FROM Conversions IMPORT
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ConvertInteger, ConvertCardinal;
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FROM RealConversions IMPORT
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LongRealToString, StringToLongReal;
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FROM Traps IMPORT Message;
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FROM Streams IMPORT Stream, StreamKind, StreamMode, StreamResult,
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InputStream, OutputStream, OpenStream, CloseStream,
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EndOfStream, Read, Write, StreamBuffering;
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FROM Storage IMPORT Allocate;
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FROM SYSTEM IMPORT ADR;
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TYPE charset = SET OF CHAR;
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btype = (Preading, Pwriting, free);
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CONST spaces = charset{11C, 12C, 13C, 14C, 15C, ' '};
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TYPE IOstream = RECORD
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type: btype;
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done, eof : BOOLEAN;
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ch: CHAR;
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next: Text;
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stream: Stream;
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END;
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Text = POINTER TO IOstream;
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numbuf = ARRAY[0..255] OF CHAR;
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VAR ibuf, obuf: IOstream;
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head: Text;
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result: StreamResult;
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PROCEDURE Reset(VAR InputText: Text; Filename: ARRAY OF CHAR);
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BEGIN
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doclose(InputText);
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getstruct(InputText);
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WITH InputText^ DO
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OpenStream(stream, Filename, text, reading, result);
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IF result # succeeded THEN
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Message("could not open input file");
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HALT;
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END;
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type := Preading;
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done := FALSE;
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eof := FALSE;
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END;
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END Reset;
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PROCEDURE Rewrite(VAR OutputText: Text; Filename: ARRAY OF CHAR);
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BEGIN
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doclose(OutputText);
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getstruct(OutputText);
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WITH OutputText^ DO
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OpenStream(stream, Filename, text, writing, result);
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IF result # succeeded THEN
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Message("could not open output file");
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HALT;
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END;
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type := Pwriting;
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END;
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END Rewrite;
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PROCEDURE CloseOutput();
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VAR p: Text;
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BEGIN
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p := head;
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WHILE p # NIL DO
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doclose(p);
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p := p^.next;
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END;
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END CloseOutput;
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PROCEDURE doclose(Xtext: Text);
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BEGIN
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IF Xtext # Notext THEN
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WITH Xtext^ DO
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IF type # free THEN
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CloseStream(stream, result);
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type := free;
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END;
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END;
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END;
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END doclose;
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PROCEDURE getstruct(VAR Xtext: Text);
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BEGIN
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Xtext := head;
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WHILE (Xtext # NIL) AND (Xtext^.type # free) DO
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Xtext := Xtext^.next;
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END;
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IF Xtext = NIL THEN
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Allocate(Xtext,SIZE(IOstream));
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Xtext^.next := head;
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head := Xtext;
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END;
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END getstruct;
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PROCEDURE Error(tp: btype);
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BEGIN
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IF tp = Preading THEN
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Message("input text expected");
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ELSE
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Message("output text expected");
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END;
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HALT;
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END Error;
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PROCEDURE ReadChar(InputText: Text; VAR ch : CHAR);
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BEGIN
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ch := NextChar(InputText);
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IF InputText^.eof THEN
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Message("unexpected EOF");
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HALT;
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END;
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InputText^.done := FALSE;
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END ReadChar;
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PROCEDURE NextChar(InputText: Text): CHAR;
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BEGIN
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WITH InputText^ DO
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IF type # Preading THEN Error(Preading); END;
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IF NOT done THEN
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IF EndOfStream(stream, result) THEN
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eof := TRUE;
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ch := 0C;
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ELSE
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Read(stream, ch, result);
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done := TRUE;
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END;
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END;
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RETURN ch;
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END;
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END NextChar;
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PROCEDURE Get(InputText: Text);
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VAR dummy: CHAR;
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BEGIN
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ReadChar(InputText, dummy);
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END Get;
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PROCEDURE Eoln(InputText: Text): BOOLEAN;
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BEGIN
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RETURN NextChar(InputText) = 12C;
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END Eoln;
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PROCEDURE Eof(InputText: Text): BOOLEAN;
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BEGIN
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RETURN (NextChar(InputText) = 0C) AND InputText^.eof;
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END Eof;
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PROCEDURE ReadLn(InputText: Text);
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VAR ch: CHAR;
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BEGIN
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REPEAT
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ReadChar(InputText, ch)
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UNTIL ch = 12C;
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END ReadLn;
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PROCEDURE WriteChar(OutputText: Text; char: CHAR);
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BEGIN
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WITH OutputText^ DO
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IF type # Pwriting THEN Error(Pwriting); END;
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Write(stream, char, result);
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END;
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END WriteChar;
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PROCEDURE WriteLn(OutputText: Text);
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BEGIN
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WriteChar(OutputText, 12C);
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END WriteLn;
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PROCEDURE Page(OutputText: Text);
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BEGIN
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WriteChar(OutputText, 14C);
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END Page;
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PROCEDURE ReadInteger(InputText: Text; VAR int : INTEGER);
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CONST
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SAFELIMITDIV10 = MAX(INTEGER) DIV 10;
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SAFELIMITREM10 = MAX(INTEGER) MOD 10;
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VAR
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neg : BOOLEAN;
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safedigit: CARDINAL;
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ch: CHAR;
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chvalue: CARDINAL;
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BEGIN
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WHILE NextChar(InputText) IN spaces DO
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Get(InputText);
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END;
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ch := NextChar(InputText);
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IF ch = '-' THEN
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Get(InputText);
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ch := NextChar(InputText);
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neg := TRUE;
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ELSIF ch = '+' THEN
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Get(InputText);
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ch := NextChar(InputText);
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neg := FALSE;
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ELSE
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neg := FALSE
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END;
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safedigit := SAFELIMITREM10;
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IF neg THEN safedigit := safedigit + 1 END;
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int := 0;
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IF (ch >= '0') AND (ch <= '9') THEN
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WHILE (ch >= '0') & (ch <= '9') DO
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chvalue := ORD(ch) - ORD('0');
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IF (int < -SAFELIMITDIV10) OR
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( (int = -SAFELIMITDIV10) AND
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(chvalue > safedigit)) THEN
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Message("integer too large");
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HALT;
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ELSE
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int := 10*int - VAL(INTEGER, chvalue);
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Get(InputText);
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ch := NextChar(InputText);
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END;
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END;
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IF NOT neg THEN
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int := -int
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END;
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ELSE
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Message("integer expected");
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HALT;
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END;
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END ReadInteger;
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PROCEDURE ReadCardinal(InputText: Text; VAR card : CARDINAL);
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CONST
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SAFELIMITDIV10 = MAX(CARDINAL) DIV 10;
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SAFELIMITREM10 = MAX(CARDINAL) MOD 10;
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VAR
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ch : CHAR;
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safedigit: CARDINAL;
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chvalue: CARDINAL;
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BEGIN
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WHILE NextChar(InputText) IN spaces DO
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Get(InputText);
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END;
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ch := NextChar(InputText);
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safedigit := SAFELIMITREM10;
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card := 0;
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IF (ch >= '0') AND (ch <= '9') THEN
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WHILE (ch >= '0') & (ch <= '9') DO
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chvalue := ORD(ch) - ORD('0');
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IF (card > SAFELIMITDIV10) OR
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( (card = SAFELIMITDIV10) AND
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(chvalue > safedigit)) THEN
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Message("cardinal too large");
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HALT;
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ELSE
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card := 10*card + chvalue;
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Get(InputText);
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ch := NextChar(InputText);
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END;
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END;
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ELSE
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Message("cardinal expected");
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HALT;
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END;
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END ReadCardinal;
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PROCEDURE ReadReal(InputText: Text; VAR real: REAL);
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VAR x1: LONGREAL;
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BEGIN
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ReadLongReal(InputText, x1);
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real := x1
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END ReadReal;
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PROCEDURE ReadLongReal(InputText: Text; VAR real: LONGREAL);
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VAR
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buf: numbuf;
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ch: CHAR;
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ok: BOOLEAN;
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index: INTEGER;
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PROCEDURE inch(): CHAR;
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BEGIN
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buf[index] := ch;
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INC(index);
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Get(InputText);
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RETURN NextChar(InputText);
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END inch;
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BEGIN
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index := 0;
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ok := TRUE;
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WHILE NextChar(InputText) IN spaces DO
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Get(InputText);
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END;
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ch := NextChar(InputText);
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IF (ch ='+') OR (ch = '-') THEN
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ch := inch();
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END;
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IF (ch >= '0') AND (ch <= '9') THEN
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WHILE (ch >= '0') AND (ch <= '9') DO
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ch := inch();
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END;
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IF (ch = '.') THEN
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ch := inch();
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IF (ch >= '0') AND (ch <= '9') THEN
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WHILE (ch >= '0') AND (ch <= '9') DO
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ch := inch();
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END;
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ELSE
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ok := FALSE;
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END;
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END;
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IF ok AND (ch = 'E') THEN
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ch := inch();
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IF (ch ='+') OR (ch = '-') THEN
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ch := inch();
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END;
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IF (ch >= '0') AND (ch <= '9') THEN
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WHILE (ch >= '0') AND (ch <= '9') DO
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ch := inch();
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END;
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ELSE
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ok := FALSE;
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END;
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END;
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ELSE
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ok := FALSE;
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END;
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IF ok THEN
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buf[index] := 0C;
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StringToLongReal(buf, real, ok);
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END;
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IF NOT ok THEN
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Message("Illegal real");
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HALT;
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END;
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END ReadLongReal;
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PROCEDURE WriteCardinal(OutputText: Text; card: CARDINAL; width: CARDINAL);
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VAR
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buf : numbuf;
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BEGIN
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ConvertCardinal(card, 1, buf);
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WriteString(OutputText, buf, width);
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END WriteCardinal;
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PROCEDURE WriteInteger(OutputText: Text; int: INTEGER; width: CARDINAL);
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VAR
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buf : numbuf;
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BEGIN
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ConvertInteger(int, 1, buf);
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WriteString(OutputText, buf, width);
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END WriteInteger;
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PROCEDURE WriteBoolean(OutputText: Text; bool: BOOLEAN; width: CARDINAL);
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BEGIN
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IF bool THEN
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WriteString(OutputText, " TRUE", width);
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ELSE
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WriteString(OutputText, "FALSE", width);
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END;
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END WriteBoolean;
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PROCEDURE WriteReal(OutputText: Text; real: REAL; width, nfrac: CARDINAL);
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BEGIN
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WriteLongReal(OutputText, LONG(real), width, nfrac)
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END WriteReal;
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PROCEDURE WriteLongReal(OutputText: Text; real: LONGREAL; width, nfrac: CARDINAL);
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VAR
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buf: numbuf;
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ok: BOOLEAN;
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digits: INTEGER;
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BEGIN
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IF width > SIZE(buf) THEN
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width := SIZE(buf);
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END;
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IF nfrac > 0 THEN
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LongRealToString(real, width, nfrac, buf, ok);
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ELSE
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IF width < 9 THEN width := 9; END;
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IF real < 0.0D THEN
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digits := 7 - INTEGER(width);
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ELSE
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digits := 6 - INTEGER(width);
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END;
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LongRealToString(real, width, digits, buf, ok);
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END;
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WriteString(OutputText, buf, 0);
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END WriteLongReal;
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PROCEDURE WriteString(OutputText: Text; str: ARRAY OF CHAR; width: CARDINAL);
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VAR index: CARDINAL;
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BEGIN
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index := 0;
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WHILE (index <= HIGH(str)) AND (str[index] # Eos) DO
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INC(index);
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END;
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WHILE index < width DO
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WriteChar(OutputText, " ");
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INC(index);
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END;
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index := 0;
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WHILE (index <= HIGH(str)) AND (str[index] # Eos) DO
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WriteChar(OutputText, str[index]);
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INC(index);
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END;
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END WriteString;
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BEGIN (* PascalIO initialization *)
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WITH ibuf DO
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stream := InputStream;
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eof := FALSE;
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type := Preading;
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done := FALSE;
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END;
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WITH obuf DO
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stream := OutputStream;
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eof := FALSE;
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type := Pwriting;
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END;
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Notext := NIL;
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Input := ADR(ibuf);
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Output := ADR(obuf);
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Input^.next := Output;
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Output^.next := NIL;
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head := Input;
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END PascalIO.
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