PACKET character buffer                            (* Autor : J.Durchholz *) 
                                                   (* Datum : 09.05.1984  *) 
    DEFINES                                        (* Version 1.7.2       *) 
                                      (* 21.2.83. hey 293, 450,97,361 *)
  get char, 
  line nr, 
  init char buffer: 
 
 
TEXT VAR buffer; 
INT VAR pointer, 
        line; 
 
 
INT PROC line nr: 
  line 
END PROC line nr; 
 
 
PROC init char buffer: 
  buffer := ""; 
  pointer := 1; 
  line := 0; 
END PROC init char buffer; 
 
 
PROC get char (FILE VAR f, TEXT VAR char): 
  IF buffer empty THEN 
    try to find nonempty line and put it into buffer; 
    char := " "; 
    pointer := 1 
  ELSE 
    char := buffer SUB pointer; 
    pointer INCR 1 
  FI. 
 
buffer empty: 
  pointer > length (buffer). 
 
try to find nonempty line and put it into buffer: 
  REP 
    IF eof (f) THEN 
      char := ""; 
      LEAVE get char 
    FI; 
    get line (f, buffer); 
    line INCR 1 
  UNTIL buffer <> "" PER. 
 
END PROC get char; 
 
 
END PACKET character buffer; 
 
 
 
 
PACKET lisp io                                      (* Autor: J.Durchholz *) 
                                                    (* Datum: 10.09.1982  *) 
    DEFINES                                         (* Version 4.1.3      *) 
                                                    (* Änderung: notebook *)
  put,  note,                                       (*    13.3.86  I. Ley *)
  verbose lisp output, 
  get, 
  get all: 
 
 
BOOL VAR verbose :: FALSE; 
 
 
PROC verbose lisp output (BOOL CONST b): 
  verbose := b 
END PROC verbose lisp output; 
 
BOOL PROC verbose lisp output: 
  verbose 
END PROC verbose lisp output; 
 
 
PROC put (SYM CONST sym): 
  IF atom (sym) THEN 
    put atom 
  ELSE 
    put structure 
  FI. 
 
put atom: 
  IF is named atom (sym) THEN 
    put (name (sym)) 
  ELIF is int pair (sym) THEN 
    put (int 1 (sym)) 
  ELIF is text (sym) THEN 
    IF verbose THEN 
      TEXT VAR buffer :: text (sym); 
      change all (buffer, """", """"""); 
      buffer CAT """"; 
      put ("""" + buffer) 
    ELSE 
      write (text (sym)) 
    FI 
  ELIF is character (sym) THEN 
    IF verbose THEN 
      buffer := "'"; 
      buffer CAT code (character (sym)); 
      buffer CAT "'"; 
      put (buffer) 
    ELSE 
      out (code (character (sym))) 
    FI 
  ELSE 
    put (""15"UNBEKANNTER_ATOM_TYP"14"") 
  FI. 
 
put structure: 
  put ("("); 
  SYM VAR actual node := sym; 
  REP 
    put (head (actual node)); 
    actual node := tail (actual node) 
  UNTIL atom (actual node) PER; 
  IF NOT null (actual node) THEN 
    put ("."); 
    put (actual node) 
  FI; 
  put (")"). 
 
END PROC put; 
 
PROC put (FILE VAR f, SYM CONST sym): 
  IF atom (sym) THEN 
    put atom 
  ELSE 
    put structure 
  FI. 
 
put atom: 
  IF is named atom (sym) THEN 
    put (f, name (sym)) 
  ELIF is int pair (sym) THEN 
    put (f, int 1 (sym)) 
  ELIF is text (sym) THEN 
    IF verbose THEN 
      TEXT VAR buffer :: text (sym); 
      change all (buffer, """", """"""); 
      buffer CAT """"; 
      put (f, """" + buffer) 
    ELSE 
      put (f, text (sym)) 
    FI 
  ELIF is character (sym) THEN 
    IF verbose THEN 
      buffer := "'"; 
      buffer CAT code (character (sym)); 
      buffer CAT "'"; 
      put (f,  buffer) 
    ELSE 
      put (f,  code (character (sym))) 
    FI 
  ELSE 
    put ( f, ""15"UNBEKANNTER_ATOM_TYP"14"") 
  FI. 
 
put structure: 
  put (f, "("); 
  SYM VAR actual node := sym; 
  REP 
    put (f, head (actual node)); 
    actual node := tail (actual node) 
  UNTIL atom (actual node) PER; 
  IF NOT null (actual node) THEN 
    put (f, "."); 
    put (f, actual node) 
  FI; 
  put (f, ")"). 
 
END PROC put; 
 
 PROC note (SYM CONST sym): 
  IF atom (sym) THEN 
    note atom 
  ELSE 
    note structure 
  FI. 
 
note atom: 
  IF is named atom (sym) THEN 
    note ( name (sym)) 
  ELIF is int pair (sym) THEN 
    note (int 1 (sym)) 
  ELIF is text (sym) THEN 
    IF verbose THEN 
      TEXT VAR buffer :: text (sym); 
      change all (buffer, """", """"""); 
      buffer CAT """"; 
      note ( """" + buffer) 
    ELSE 
      note ( text (sym)) 
    FI 
  ELIF is character (sym) THEN 
    IF verbose THEN 
      buffer := "'"; 
      buffer CAT code (character (sym)); 
      buffer CAT "'"; 
      note ( buffer) 
    ELSE 
      note ( code (character (sym))) 
    FI 
  ELSE 
    note ( ""15"UNBEKANNTER_ATOM_TYP"14"") 
  FI. 
 
note structure: 
  note ( "("); 
  SYM VAR actual node := sym; 
  REP 
    note ( head (actual node)); 
    actual node := tail (actual node) 
  UNTIL atom (actual node) PER; 
  IF NOT null (actual node) THEN 
    note ( "."); 
    note ( actual node) 
  FI; 
  note ( ")"). 
 
END PROC note; 
 
PROC get (FILE VAR f, SYM VAR s): 
  initialize scanner (f); 
  IF NOT get s expression (s) THEN 
    error ("LISP-Ausdruck erwartet") 
  FI; 
  scanner postprocessing (f) 
END PROC get; 
 
 
(**************************** parser for 'get' ****************************) 
 
 
LET end of file type = 0, 
    name type = 1, 
    text type = 2, 
    character type = 3, 
    int type = 4, 
    other char type = 5; 
 
 
BOOL PROC get s expression (SYM VAR s): 
  (* The boolean result indicates wether the error has not occurred that  *) 
  (* 'get next symbol' was called, but then the symbol was not expected   *) 
  (* and thus could not be processed.                                     *) 
  get next symbol; 
  SELECT symbol type OF 
    CASE end of file type: FALSE 
    CASE name type: s := new atom (symbol); TRUE 
    CASE text type: s := sym (symbol); TRUE 
    CASE character type: s := sym character (code (symbol)); TRUE 
    CASE int type: s := sym (int (symbol), -1); TRUE 
    CASE other char type: get structure 
    OTHERWISE error ("EINLESEFEHLER: unbekannter Symboltyp: " + 
                     text (symbol type)); TRUE 
  END SELECT. 
 
get structure: 
  IF symbol <> "(" THEN 
    FALSE 
  ELSE 
    get list; 
    IF symbol type <> other char type OR symbol <> ")" THEN 
      error (">> ) << erwartet"); 
      FALSE 
    ELSE 
      TRUE 
    FI 
  FI. 
 
get list: 
  SYM VAR father, son; 
  IF get s expression (son) THEN 
    get list elements; 
  ELSE 
    s := nil 
  FI. 
 
get list elements: 
  father := cons (son, nil); 
  s := father; 
  WHILE get s expression (son) REP 
    set tail (father, cons (son, nil)); 
    father := tail (father) 
  PER; 
  IF symbol type = other char type AND symbol = "." THEN 
    IF get s expression (son) THEN 
      set tail (father, son); 
      get next symbol 
    ELSE 
      error ("LISP-Ausdruck nach dem Punkt erwartet") 
    FI 
  FI. 
 
END PROC get s expression; 
 
 
(********************* scanner for 'get x espression' *********************) 
 
 
FILE VAR infile; 
 
 
PROC initialize scanner (FILE CONST f): 
  infile := f; 
  no input errors := TRUE; 
  init char buffer; 
  get char (infile, actual char) 
END PROC initialize scanner; 
 
 
PROC scanner postprocessing (FILE VAR f): 
  f := infile 
END PROC scanner postprocessing; 
 
 
TEXT VAR symbol; INT VAR symbol type; 
 
 
PROC get next symbol: 
  skip blanks; 
  IF actual char = "" THEN 
    symbol := "DATEIENDE"; 
    symbol type := end of file type 
  ELIF is letter THEN 
    get name 
  ELIF is digit or sign THEN 
    get integer 
  ELIF is double quote THEN 
    get text 
  ELIF is single quote THEN 
    get character 
  ELSE 
    get other char 
  FI .
 
is letter: 
  IF "a" <= actual char AND actual char <= "z" THEN 
    actual char := code (code (actual char) - code ("a") + code ("A")); 
    TRUE 
  ELSE 
    "§" <= actual char AND actual char <= "Z" 
  FI. 
 
get name: 
  symbol type := name type; 
  symbol := actual char; 
  REP 
    get char (infile, actual char); 
    IF is neither letter nor digit THEN 
      LEAVE get name 
    FI; 
    symbol CAT actual char 
  PER. 
 
is neither letter nor digit: 
  NOT (is letter OR is digit OR is underscore). 
 
is digit: 
  "0" <= actual char AND actual char <= "9". 
 
is underscore: 
  actual char = "_". 
 
is digit or sign: 
  is digit OR actual char = "+" OR actual char = "-". 
 
get integer: 
  symbol type := int type; 
  IF actual char = "+" THEN 
    get char (infile, actual char); 
    skip blanks; 
    symbol := actual char 
  ELIF actual char = "-" THEN 
    symbol := "-"; 
    get char (infile, actual char); 
    skip blanks; 
    symbol CAT actual char 
  ELSE 
    symbol := actual char 
  FI; 
  REP 
    get char (infile, actual char); 
    IF NOT is digit THEN 
      LEAVE get integer 
    FI; 
    symbol CAT actual char 
  PER. 
 
is double quote: 
  actual char = """". 
 
get text: 
  symbol := ""; 
  symbol type := text type; 
  REP 
    get char (infile, actual char); 
    IF is double quote THEN 
      get char (infile, actual char); 
      IF NOT is double quote THEN LEAVE get text 
      FI 
    ELIF actual char = ""    THEN LEAVE get text  (*hey*)
    FI; 
    symbol CAT actual char 
  PER. 
 
is single quote: 
  actual char = "'". 
 
get character: 
  symbol type := character type; 
  get char (infile, symbol); 
  get char (infile, actual char); 
  IF actual char <> "'" THEN 
    error (">> ' << erwartet") 
  ELSE 
    get char (infile, actual char) 
  FI. 
 
get other char: 
  symbol type := other char type; 
  symbol := actual char; 
  get char (infile, actual char). 
 
END PROC get next symbol; 
 
 
TEXT VAR actual char; 
 
 
PROC skip blanks: 
  INT VAR comment depth :: 0; 
  WHILE is comment OR actual char = " " REP 
    get char (infile, actual char) 
  PER. 
 
is comment: 
  IF actual char = "{" THEN 
    comment depth INCR 1; 
    TRUE 
  ELIF actual char = "}" THEN 
    IF comment depth = 0 THEN 
      error (">> { << fehlt") 
    ELSE 
      comment depth DECR 1 
    FI; 
    TRUE 
  ELSE 
    IF comment depth > 0 THEN 
      IF actual char = "" THEN 
        error ("DATEIENDE im Kommentar"); 
        FALSE 
      ELSE 
        TRUE 
      FI 
    ELSE 
      FALSE 
    FI 
  FI. 
 
END PROC skip blanks; 
 
 
BOOL VAR no input errors; 
FILE VAR errors; 
 
 
PROC error (TEXT CONST error message): 
  out ("FEHLER in Zeile "); 
  out (text (line nr)); 
  out (" bei >> "); 
  out (symbol); 
  out (" << : "); 
  out (error message); 
  line; 
  IF no input errors THEN 
    no input errors := FALSE; 
    errors := notefile; modify(errors);
    headline (errors, "Einlesefehler"); output(errors)
  FI; 
  write (errors, "FEHLER in Zeile "); 
  write (errors, text (line nr)); 
  write (errors, " bei >> "); 
  write (errors, symbol); 
  write (errors, " << : "); 
  write (errors, error message); 
  line (errors) 
END PROC error; 
 
 
PROC get (SYM VAR sym):     (*hey*)
  disable stop; 
  FILE VAR in  :: sequential file (modify, "LISP INPUT"), 
           out :: notefile; modify (out);
  headline (out,"LISP OUTPUT");
  headline (in, "LISP INPUT");
  noteedit (in);
  input (in); 
  get (in, sym); 
  WHILE NOT no input errors AND NOT is error REP 
    modify (errors);
    headline (errors, " LISP-Fehlermeldungen"); 
    headline (in, " Bitte KORREKTEN LISP-Ausdruck"); 
    noteedit (in); 
    headline (errors, "notebook"); 
    input (in); 
    get (in, sym) 
  PER; 
END PROC get; 
 
 
PROC get all (FILE VAR f, SYM VAR sym): 
  get (f, sym); 
  skip blanks; 
  IF NOT eof (infile) THEN 
    error ("Hinter dem letzten Symbol des LISP-Ausdruck stehen noch Zeichen") 
  FI 
END PROC get all; 
 
 
END PACKET lisp io; 
 
 
 
PACKET lisp integer                                 (* Autor: J.Durchholz *) 
                                                    (* Datum: 30.08.1982  *) 
    DEFINES                                         (* Version 1.1.2      *) 
 
  sum, 
  difference, 
  product, 
  quotient,
  remainder:
 
SYM PROC sum (SYM CONST summand list): 
  INT VAR result := 0; 
  SYM VAR list rest := summand list; 
  WHILE NOT atom (list rest) REP 
    result INCR int 1 (head (list rest)); 
    list rest := tail (list rest) 
  PER; 
  IF NOT null (list rest) THEN 
    error stop ("Summandenliste endet falsch") 
  FI ;
  sym (result, -1) 
END PROC sum; 
 
 
SYM PROC difference (SYM CONST minuend, subtrahend): 
  sym (int 1 (minuend) - int 1 (subtrahend), -1) 
END PROC difference; 
 
 
SYM PROC product (SYM CONST factor list): 
  INT VAR result := 1; 
  SYM VAR list rest := factor list; 
  WHILE NOT atom (list rest) REP 
    result := result * int 1 (head (list rest)); 
    list rest := tail (list rest) 
  PER; 
  IF NOT null (list rest) THEN 
    error stop ("Faktorenliste endet falsch") 
  FI; 
  sym (result, -1) 
END PROC product; 
 
 
SYM PROC quotient (SYM CONST dividend, divisor): 
  sym (int 1 (dividend) DIV int 1 (divisor), -1) 
END PROC quotient; 
 
 
SYM PROC remainder(SYM CONST dividend, divisor): 
  sym (int 1 (dividend) MOD int 1 (divisor), -1) 
END PROC remainder;
 
 
END PACKET lisp integer;