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
  39     if( value.type == "string" )
  40     {
  41         return Printer.pr_str(value, false);
  42     }
  43     else
  44     {
  45         return "exception: " + Printer.pr_str(value, true);
  46     }
  47 }
  48
  49 fun string rep(string input)
  50 {
  51     READ(input) @=> MalObject m;
  52
  53     if( m.type == "error" )
  54     {
  55         return errorMessage(m);
  56     }
  57     else
  58     {
  59         return PRINT(EVAL(m));
  60     }
  61 }
  62
  63 fun void main()
  64 {
  65     int done;
  66
  67     while( !done )
  68     {
  69         Readline.readline("user> ") => string input;
  70
  71         if( input != null )
  72         {
  73             rep(input) => string output;
  74
  75             if( output == "empty input" )
  76             {
  77                 // proceed immediately with prompt
  78             }
  79             else
  80             {
  81                 Util.println(output);
  82             }
  83         }
  84         else
  85         {
  86             true => done;
  87         }
  88     }
  89 }
  90
  91 main();