cs/step6_file.cs

   1 using System;
   2 using System.IO;
   3 using System.Collections;
   4 using System.Collections.Generic;
   5 using Mal;
   6 using MalVal = Mal.types.MalVal;
   7 using MalString = Mal.types.MalString;
   8 using MalSymbol = Mal.types.MalSymbol;
   9 using MalInt = Mal.types.MalInt;
  10 using MalList = Mal.types.MalList;
  11 using MalVector = Mal.types.MalVector;
  12 using MalHashMap = Mal.types.MalHashMap;
  13 using MalFunc = Mal.types.MalFunc;
  14 using Env = Mal.env.Env;
  15
  16 namespace Mal {
  17     class step6_file {
  18         // read
  19         static MalVal READ(string str) {
  20             return reader.read_str(str);
  21         }
  22
  23         // eval
  24         static MalVal eval_ast(MalVal ast, Env env) {
  25             if (ast is MalSymbol) {
  26                 return env.get((MalSymbol)ast);
  27             } else if (ast is MalList) {
  28                 MalList old_lst = (MalList)ast;
  29                 MalList new_lst = ast.list_Q() ? new MalList()
  30                                             : (MalList)new MalVector();
  31                 foreach (MalVal mv in old_lst.getValue()) {
  32                     new_lst.conj_BANG(EVAL(mv, env));
  33                 }
  34                 return new_lst;
  35             } else if (ast is MalHashMap) {
  36                 var new_dict = new Dictionary<string, MalVal>();
  37                 foreach (var entry in ((MalHashMap)ast).getValue()) {
  38                     new_dict.Add(entry.Key, EVAL((MalVal)entry.Value, env));
  39                 }
  40                 return new MalHashMap(new_dict);
  41             } else {
  42                 return ast;
  43             }
  44         }
  45
  46
  47         static MalVal EVAL(MalVal orig_ast, Env env) {
  48             MalVal a0, a1, a2, res;
  49             MalList el;
  50
  51             while (true) {
  52
  53             //Console.WriteLine("EVAL: " + printer._pr_str(orig_ast, true));
  54             if (!orig_ast.list_Q()) {
  55                 return eval_ast(orig_ast, env);
  56             }
  57
  58             // apply list
  59             MalList ast = (MalList)orig_ast;
  60             if (ast.size() == 0) { return ast; }
  61             a0 = ast[0];
  62
  63             String a0sym = a0 is MalSymbol ? ((MalSymbol)a0).getName()
  64                                            : "__<*fn*>__";
  65
  66             switch (a0sym) {
  67             case "def!":
  68                 a1 = ast[1];
  69                 a2 = ast[2];
  70                 res = EVAL(a2, env);
  71                 env.set((MalSymbol)a1, res);
  72                 return res;
  73             case "let*":
  74                 a1 = ast[1];
  75                 a2 = ast[2];
  76                 MalSymbol key;
  77                 MalVal val;
  78                 Env let_env = new Env(env);
  79                 for(int i=0; i<((MalList)a1).size(); i+=2) {
  80                     key = (MalSymbol)((MalList)a1)[i];
  81                     val = ((MalList)a1)[i+1];
  82                     let_env.set(key, EVAL(val, let_env));
  83                 }
  84                 orig_ast = a2;
  85                 env = let_env;
  86                 break;
  87             case "do":
  88                 eval_ast(ast.slice(1, ast.size()-1), env);
  89                 orig_ast = ast[ast.size()-1];
  90                 break;
  91             case "if":
  92                 a1 = ast[1];
  93                 MalVal cond = EVAL(a1, env);
  94                 if (cond == Mal.types.Nil || cond == Mal.types.False) {
  95                     // eval false slot form
  96                     if (ast.size() > 3) {
  97                         orig_ast = ast[3];
  98                     } else {
  99                         return Mal.types.Nil;
 100                     }
 101                 } else {
 102                     // eval true slot form
 103                     orig_ast = ast[2];
 104                 }
 105                 break;
 106             case "fn*":
 107                 MalList a1f = (MalList)ast[1];
 108                 MalVal a2f = ast[2];
 109                 Env cur_env = env;
 110                 return new MalFunc(a2f, env, a1f,
 111                     args => EVAL(a2f, new Env(cur_env, a1f, args)) );
 112             default:
 113                 el = (MalList)eval_ast(ast, env);
 114                 var f = (MalFunc)el[0];
 115                 MalVal fnast = f.getAst();
 116                 if (fnast != null) {
 117                     orig_ast = fnast;
 118                     env = f.genEnv(el.rest());
 119                 } else {
 120                     return f.apply(el.rest());
 121                 }
 122                 break;
 123             }
 124
 125             }
 126         }
 127
 128         // print
 129         static string PRINT(MalVal exp) {
 130             return printer._pr_str(exp, true);
 131         }
 132
 133         // repl
 134         static void Main(string[] args) {
 135             var repl_env = new Mal.env.Env(null);
 136             Func<string, MalVal> RE = (string str) => EVAL(READ(str), repl_env);
 137
 138             // core.cs: defined using C#
 139             foreach (var entry in core.ns) {
 140                 repl_env.set(new MalSymbol(entry.Key), entry.Value);
 141             }
 142             repl_env.set(new MalSymbol("eval"), new MalFunc(
 143                         a => EVAL(a[0], repl_env)));
 144             int fileIdx = 0;
 145             if (args.Length > 0 && args[0] == "--raw") {
 146                 Mal.readline.mode = Mal.readline.Mode.Raw;
 147                 fileIdx = 1;
 148             }
 149             MalList _argv = new MalList();
 150             for (int i=fileIdx+1; i < args.Length; i++) {
 151                 _argv.conj_BANG(new MalString(args[i]));
 152             }
 153             repl_env.set(new MalSymbol("*ARGV*"), _argv);
 154
 155             // core.mal: defined using the language itself
 156             RE("(def! not (fn* (a) (if a false true)))");
 157             RE("(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))");
 158
 159             if (args.Length > fileIdx) {
 160                 RE("(load-file \"" + args[fileIdx] + "\")");
 161                 return;
 162             }
 163
 164             // repl loop
 165             while (true) {
 166                 string line;
 167                 try {
 168                     line = Mal.readline.Readline("user> ");
 169                     if (line == null) { break; }
 170                     if (line == "") { continue; }
 171                 } catch (IOException e) {
 172                     Console.WriteLine("IOException: " + e.Message);
 173                     break;
 174                 }
 175                 try {
 176                     Console.WriteLine(PRINT(RE(line)));
 177                 } catch (Mal.types.MalContinue) {
 178                     continue;
 179                 } catch (Exception e) {
 180                     Console.WriteLine("Error: " + e.Message);
 181                     Console.WriteLine(e.StackTrace);
 182                     continue;
 183                 }
 184             }
 185         }
 186     }
 187 }