vala/step1_read_print.vala

   1 class Mal.Main : GLib.Object {
   2     static bool eof;
   3
   4     static construct {
   5         eof = false;
   6     }
   7
   8     public static Mal.Val? READ() {
   9         string? line = Readline.readline("user> ");
  10         if (line != null) {
  11             if (line.length > 0)
  12                 Readline.History.add(line);
  13
  14             try {
  15                 return Reader.read_str(line);
  16             } catch (Mal.Error err) {
  17                 GLib.stderr.printf("%s\n", err.message);
  18                 return null;
  19             }
  20         } else {
  21             stdout.printf("\n");
  22             eof = true;
  23             return null;
  24         }
  25     }
  26
  27     public static Mal.Val EVAL(Mal.Val expr) {
  28         return expr;
  29     }
  30
  31     public static void PRINT(Mal.Val value) {
  32         stdout.printf("%s\n", pr_str(value));
  33     }
  34
  35     public static void rep() {
  36         Mal.Val? val = READ();
  37         if (val != null) {
  38             val = EVAL(val);
  39             PRINT(val);
  40         }
  41     }
  42
  43     public static int main(string[] args) {
  44         while (!eof)
  45             rep();
  46         return 0;
  47     }
  48 }