-- file:  PascalNoviceFiles.mesa
-- last modified by Ramshaw, December 25, 1982 10:21 am
-- written by McCreight, November 17, 1980  3:13 PM

-- Pascal files for the novice user:  slow, but anything works

DIRECTORY
  IO USING [STREAM],
  PascalBasic;

PascalNoviceFiles: CEDAR DEFINITIONS =

  BEGIN  OPEN PascalBasic;

  --                T Y P E S

  PascalFile: TYPE = LONG POINTER TO MesaFile _ NIL;
  PascalFilePtr: TYPE = LONG POINTER TO PascalFile;  --  for passing files as VAR parameters
  
  MesaFile: TYPE = RECORD [
    name: ROPE,
    in, out, inSource, inSource2, outDest, outDest2: IO.STREAM _ NIL,
    eof: BOOLEAN _ FALSE,
    openFileLink: MesaFilePtr _ NIL];
  MesaFilePtr: TYPE = REF MesaFile;
  
  TextControl: TYPE = RECORD [
    readLowerCase: PascalBoolean _ TRUE,
    readUpperCase: PascalBoolean _ TRUE,
    readAllControlChars: PascalBoolean _ FALSE,
    writeLowerCase: PascalBoolean _ TRUE,
    writeUpperCase: PascalBoolean _ TRUE,
    writeAllControlChars: PascalBoolean _ TRUE];

  PascalTextFile: TYPE = RECORD [
    baseFile: PascalFile,  
    eoln: BOOLEAN _ TRUE, -- TRUE if element is a blank representing CR
    control: TextControl,
    lineNo: PascalInteger _ 1, -- line number
    validElement: BOOLEAN _ FALSE,
    element: PascalChar _ '  -- last character read
    ];
  PascalTextFilePtr: TYPE = LONG POINTER TO PascalTextFile;  --  for passing by VAR

  Text: TYPE = PascalTextFile;

  --                V A R I A B L E S

  Input, Output, Tty: PascalTextFile;

  --                 P R O C E D U R E S   Called by PasMesa

--  Text File Operations:

  PascalTextBREAK: PROCEDURE [file: PascalTextFilePtr];
    
  PascalTextGET: PROCEDURE [file: PascalTextFilePtr];

  PascalTextElement: PROCEDURE [file: PascalTextFilePtr] RETURNS [PascalChar];

  PascalTextFinishGet: PROCEDURE [file: PascalTextFilePtr];

  PascalTextPUT: PROCEDURE [file: PascalTextFilePtr];

  PascalTextRESET: PROCEDURE [file: PascalTextFilePtr];

  PascalTextREWRITE: PROCEDURE [file: PascalTextFilePtr];

  PascalTextPAGE: PROCEDURE [file: PascalTextFilePtr];

  PascalTextEOF: PROCEDURE [file: PascalTextFilePtr] RETURNS [BOOLEAN];
 
  PascalTextEOLN: PROCEDURE [file: PascalTextFilePtr] RETURNS [BOOLEAN];

-- Binary File Operations:
--   The "length" argument is in units of bytes rather than words, but the only odd
--   value that will ever arise is 1.  The Pascal program generates these arguments
--   by utilizing a little-known feature of the SIZE operator in Mesa:  if you say
--   SIZE[T, 2], you get back the size in words of a packed array of 2 T's.

  PascalBREAK: PROCEDURE [
    file: PascalFilePtr, length: CARDINAL,
    element: LONG POINTER];
    
  PascalGET: UNSAFE PROCEDURE [
    file: PascalFilePtr, length: CARDINAL,
    element: LONG POINTER -- TO ARRAY[0..length/2) OF UNSPECIFIED --];
 
  PascalPUT: PROCEDURE [
    file: PascalFilePtr, length: CARDINAL,
    element: LONG POINTER -- TO ARRAY[0..length/2) OF UNSPECIFIED --];

  PascalRESET: UNSAFE PROCEDURE [
    file: PascalFilePtr, length: CARDINAL,
    element: LONG POINTER -- TO ARRAY[0..length/2) OF UNSPECIFIED --];

  PascalREWRITE: PROCEDURE [
    file: PascalFilePtr, length: CARDINAL _ 0,
    element: LONG POINTER -- TO ARRAY[0..length/2) OF UNSPECIFIED -- _ NIL];
-- The latter two arguments don't mean anything, and are just included since PasMesa
-- prefers to generate them.

  PascalRead, PascalReadLong, PascalWrite, PascalWriteLong: UNSAFE PROCEDURE [
    file: PascalFilePtr, length: CARDINAL,
    element: LONG POINTER -- TO ARRAY[0..length/2) OF UNSPECIFIED --,
    item: LONG POINTER -- TO ARRAY[0..length/2) OF UNSPECIFIED --];
    
  PascalEOF: PROCEDURE [file: PascalFilePtr] RETURNS [BOOLEAN];

-- formatted IO for text files

  PascalReadLn, PascalWriteLn: PROCEDURE [file: PascalTextFilePtr]; 
      -- reads up to or writes a CR

  PascalReadInteger: PROCEDURE [file: PascalTextFilePtr] RETURNS [PascalInteger];

  PascalWriteInteger: PROCEDURE [
    file: PascalTextFilePtr, item: PascalInteger,
    fieldMinLength: PascalInteger _ -1];

  PascalReadReal: PROCEDURE [file: PascalTextFilePtr] RETURNS [PascalReal];

  PascalWriteReal: PROCEDURE [
    file: PascalTextFilePtr, item: PascalReal,
    fieldMinLength, fracLength: PascalInteger _ -1];

  PascalReadChar: PROCEDURE [file: PascalTextFilePtr] RETURNS [PascalChar];

  PascalWriteChar: PROCEDURE [
    file: PascalTextFilePtr, item: PascalChar, fieldMinLength: PascalInteger _ -1];

  PascalReadBoolean: PROCEDURE [file: PascalTextFilePtr] RETURNS [PascalBoolean];

  PascalWriteBoolean: PROCEDURE [
    file: PascalTextFilePtr, item: PascalBoolean,
    fieldMinLength: PascalInteger _ -1];

  PascalReadArrayOfChar, PascalReadLongArrayOfChar: UNSAFE PROCEDURE [
    file: PascalTextFilePtr,
    item: CharArrayPtr,
    arrayBound: PascalInteger];

  PascalWriteArrayOfChar, PascalWriteLongArrayOfChar: PROCEDURE [
    file: PascalTextFilePtr,
    item: CharArrayPtr,
    arrayBound: PascalInteger, fieldMinLength: PascalInteger _ -1];

--  At this point, McCreight included the following ReadString routines, but I don't see
--  how they could ever arise, nor do I see how to make them safe.
--  PascalReadString, PascalReadLongString:
--   PROCEDURE [file: PascalTextFilePtr, item: LONG POINTER TO ??ROPE??];

  PascalWriteString, PascalWriteLongString: PROCEDURE [
    file: PascalTextFilePtr, item: ROPE, fieldMinLength: PascalInteger _ -1];



  --                 P R O C E D U R E S   NOT  Called by PasMesa
  --  (and hence, intended to be called as external procedures by the Pascal
  --   program, or else from Mesa code that implements such external procedures).

  PascalInventFileName: PROCEDURE [name: ROPE _ NIL] RETURNS [PascalFile];  
    -- Allocates a MesaFile to implement a PascalFile with the recommended name
    --  This proc is called by PasMesa if you ask PasMesa to INVENTFILENAMES

  PascalAttachFile: PROCEDURE [
    file: PascalFilePtr, dir: PascalFileDirection _ in,
    type: PascalFileType _ text];
  PascalFileType: TYPE = {text, binary};
  PascalFileDirection: TYPE = {in, out, both};

  PascalCleanupFiles: PROCEDURE;  

  END. -- PascalNoviceFiles