ada/step3_env.adb

   1 with Ada.Command_Line;
   2 with Ada.Text_IO;
   3 with Ada.IO_Exceptions;
   4 with Core;
   5 with Envs;
   6 with Evaluation;
   7 with Printer;
   8 with Reader;
   9 with Types;
  10
  11 procedure Step3_Env is
  12
  13    function Read (Param : String) return Types.Mal_Handle is
  14    begin
  15       return Reader.Read_Str (Param);
  16    end Read;
  17
  18
  19    -- Eval can't be here because there are function pointers that point
  20    -- at it.  Thus it must be at library level.  See evaluation.ads
  21
  22
  23    function Print (Param : Types.Mal_Handle) return String is
  24    begin
  25       return Printer.Pr_Str (Param);
  26    end Print;
  27
  28    function Rep (Param : String) return String is
  29      AST, Evaluated_AST : Types.Mal_Handle;
  30    begin
  31
  32      AST := Read (Param);
  33
  34      if Types.Is_Null (AST) then
  35         return "";
  36      else
  37         Evaluated_AST := Evaluation.Eval (AST, Envs.Get_Current);
  38         return Print (Evaluated_AST);
  39      end if;
  40
  41    end Rep;
  42
  43    S : String (1..Reader.Max_Line_Len);
  44    Last : Natural;
  45
  46 begin
  47
  48    if Ada.Command_Line.Argument_Count > 0 then
  49      if Ada.Command_Line.Argument (1) = "-d" then
  50         Evaluation.Debug := True;
  51      end if;
  52    end if;
  53
  54    Core.Init;
  55
  56    loop
  57       Ada.Text_IO.Put ("user> ");
  58       Ada.Text_IO.Get_Line (S, Last);
  59       Ada.Text_IO.Put_Line (Rep (S (1..Last)));
  60    end loop;
  61
  62 exception
  63    when Ada.IO_Exceptions.End_Error => null;
  64    -- i.e. exit without textual output
  65 end Step3_Env;