chuck/step1_read_print.ck

   1 // @import readline.ck
   2 // @import types/boxed/*.ck
   3 // @import types/MalObject.ck
   4 // @import types/mal/MalAtom.ck
   5 // @import types/mal/MalError.ck
   6 // @import types/mal/MalNil.ck
   7 // @import types/mal/MalFalse.ck
   8 // @import types/mal/MalTrue.ck
   9 // @import types/mal/MalInt.ck
  10 // @import types/mal/MalString.ck
  11 // @import types/mal/MalSymbol.ck
  12 // @import types/mal/MalKeyword.ck
  13 // @import types/mal/MalList.ck
  14 // @import types/mal/MalVector.ck
  15 // @import types/mal/MalHashMap.ck
  16 // @import util/*.ck
  17 // @import reader.ck
  18 // @import printer.ck
  19
  20 fun MalObject READ(string input)
  21 {
  22     return Reader.read_str(input);
  23 }
  24
  25 fun MalObject EVAL(MalObject m)
  26 {
  27     return m;
  28 }
  29
  30 fun string PRINT(MalObject m)
  31 {
  32     return Printer.pr_str(m, true);
  33 }
  34
  35 fun string errorMessage(MalObject m)
  36 {
  37     (m$MalError).value() @=> MalObject value;
  38     return "exception: " + Printer.pr_str(value, true);
  39 }
  40
  41 fun string rep(string input)
  42 {
  43     READ(input) @=> MalObject m;
  44
  45     if( m.type == "error" )
  46     {
  47         return errorMessage(m);
  48     }
  49     else
  50     {
  51         return PRINT(EVAL(m));
  52     }
  53 }
  54
  55 fun void main()
  56 {
  57     int done;
  58
  59     while( !done )
  60     {
  61         Readline.readline("user> ") => string input;
  62
  63         if( input != null )
  64         {
  65             rep(input) => string output;
  66
  67             if( output == "empty input" )
  68             {
  69                 // proceed immediately with prompt
  70             }
  71             else
  72             {
  73                 Util.println(output);
  74             }
  75         }
  76         else
  77         {
  78             true => done;
  79         }
  80     }
  81 }
  82
  83 main();