include/occam/dec.ocm

   1 -- decin/decout - Decimal i/o
   2
   3 proc decin(chan in, var d, c)=
   4 -- Reads a decimal number from input into d.  c is used as the first input
   5 -- character, and it contains the character just after the decimal number
   6 -- when decin exits.
   7
   8         var neg:
   9         seq
  10                 while (c='*s') or (c='*t') or (c='*n')
  11                         in ? c
  12                 if
  13                         (c='-') or (c='+')
  14                                 seq
  15                                         neg:=(c='-')
  16                                         in ? c
  17                         true
  18                                 neg:=false
  19                 d:=0
  20                 while ('0'<=c) and (c<='9')
  21                         seq
  22                                 d:=(d*10)+(c-'0')
  23                                 in ? c
  24                 if
  25                         neg
  26                                 d:= -d
  27 :
  28 proc decout(chan out, value d, w)=
  29 -- Sends d to channel out in decimal on a field of w spaces.  It is just like
  30 -- fprintf(out, "%*d", w, d);
  31
  32         var dec[BYTE 12], di, dd, d0, neg:
  33         seq
  34                 di:=0
  35                 if
  36                         d<0
  37                                 seq
  38                                         neg:=true
  39                                         dd:= -d
  40                         d>=0
  41                                 seq
  42                                         neg:=false
  43                                         dd:=d
  44                 d0:=1
  45                 while d0<>0
  46                         seq
  47                                 dec[BYTE di]:=(dd\10)+'0'
  48                                 di:=di+1
  49                                 dd:=dd/10
  50                                 d0:=dd
  51                 if
  52                         neg
  53                                 seq
  54                                         dec[BYTE di]:='-'
  55                                         di:=di+1
  56                 seq i=[0 for w-di]
  57                         out ! '*s'
  58                 while di<>0
  59                         seq
  60                                 di:=di-1
  61                                 out ! dec[BYTE di]
  62 :