Textfile Input and Output  135  12.C.  The Procedures Write and Writeln  The second schema processes n-tuples of numbers:  The first schema processes single numbers:  repeat  if eof(F)  then Done  := True  else  if Fi  =  '  ,  then Get (F)  else Done  .- True  until Done  end  Reset (F) ;  while not eof(F)  do  begin  Read(F,X);  SkipBlanks(F);  P  (X) ;  end  Reset(F);  while not eof(F)  do  begin  Read(F,XI, ... ,Xn);  SkipBlanks(F)  P(Xl, ... ,Xn);  end  For the above schema to function properly, the total number of  single numbers must be a multiple of n.  The procedure  Write  was defined for textfiles in Section 9.B.  Write  is extended to accept a variable number of parameters whose types are  compatible with  Integer, Real, Boolean,  or string types.  The  procedure  Write  appends  character strings  (one  or more  characters) to a textfile. Let  Pl,P2,  ...  ,Pn  be parameters of the form  defined  in  the  syntax  diagram  for  WriteParameterList  (Figure  12.a), and let  F  be a textfile. Then  Write (F,P)  is an error if  F  is  undefined or  F  is not in generation mode or if  eof (F)  is not true.  1. Write (PI, ... ,Pn)  stands for  Write (Output,PI, ... ,Pn) 