matlab/step6_file.m

   1 function step6_file(varargin), main(varargin), end
   2
   3 % read
   4 function ret = READ(str)
   5     ret = reader.read_str(str);
   6 end
   7
   8 % eval
   9 function ret = eval_ast(ast, env)
  10     switch class(ast)
  11     case 'types.Symbol'
  12         ret = env.get(ast);
  13     case 'types.List'
  14         ret = types.List();
  15         for i=1:length(ast)
  16             ret.append(EVAL(ast.get(i), env));
  17         end
  18     case 'types.Vector'
  19         ret = types.Vector();
  20         for i=1:length(ast)
  21             ret.append(EVAL(ast.get(i), env));
  22         end
  23     case 'types.HashMap'
  24         ret = types.HashMap();
  25         ks = ast.keys();
  26         for i=1:length(ks)
  27             k = ks{i};
  28             ret.set(EVAL(k, env), EVAL(ast.get(k), env));
  29         end
  30     otherwise
  31         ret = ast;
  32     end
  33 end
  34
  35 function ret = EVAL(ast, env)
  36   while true
  37     if ~types.list_Q(ast)
  38         ret = eval_ast(ast, env);
  39         return;
  40     end
  41
  42     % apply
  43     if isa(ast.get(1),'types.Symbol')
  44         a1sym = ast.get(1).name;
  45     else
  46         a1sym = '_@$fn$@_';
  47     end
  48     switch (a1sym)
  49     case 'def!'
  50         ret = env.set(ast.get(2), EVAL(ast.get(3), env));
  51         return;
  52     case 'let*'
  53         let_env = Env(env);
  54         for i=1:2:length(ast.get(2))
  55             let_env.set(ast.get(2).get(i), EVAL(ast.get(2).get(i+1), let_env));
  56         end
  57         env = let_env;
  58         ast = ast.get(3); % TCO
  59     case 'do'
  60         el = eval_ast(ast.slice(2,length(ast)-1), env);
  61         ast = ast.get(length(ast)); % TCO
  62     case 'if'
  63         cond = EVAL(ast.get(2), env);
  64         if strcmp(class(cond), 'types.Nil') || ...
  65            (islogical(cond) && cond == false)
  66            if length(ast) > 3
  67                ast = ast.get(4); % TCO
  68             else
  69                ret = types.nil;
  70                return;
  71             end
  72         else
  73             ast = ast.get(3); % TCO
  74         end
  75     case 'fn*'
  76         fn = @(varargin) EVAL(ast.get(3), Env(env, ast.get(2), ...
  77                                               types.List(varargin{:})));
  78         ret = types.Function(fn, ast.get(3), env, ast.get(2));
  79         return;
  80     otherwise
  81         el = eval_ast(ast, env);
  82         f = el.get(1);
  83         args = el.slice(2);
  84         if isa(f, 'types.Function')
  85             env = Env(f.env, f.params, args);
  86             ast = f.ast; % TCO
  87         else
  88             ret = f(args.data{:});
  89             return
  90         end
  91     end
  92   end
  93 end
  94
  95 % print
  96 function ret = PRINT(ast)
  97     ret = printer.pr_str(ast, true);
  98 end
  99
 100 % REPL
 101 function ret = rep(str, env)
 102     ret = PRINT(EVAL(READ(str), env));
 103 end
 104
 105 function main(args)
 106     repl_env = Env(false);
 107
 108     % core.m: defined using matlab
 109     ns = core.ns(); ks = ns.keys();
 110     for i=1:length(ks)
 111         k = ks{i};
 112         repl_env.set(types.Symbol(k), ns(k));
 113     end
 114     repl_env.set(types.Symbol('eval'), @(a) EVAL(a, repl_env));
 115     rest_args = args(2:end);
 116     repl_env.set(types.Symbol('*ARGV*'), types.List(rest_args{:}));
 117
 118     % core.mal: defined using the langauge itself
 119     rep('(def! not (fn* (a) (if a false true)))', repl_env);
 120     rep('(def! load-file (fn* (f) (eval (read-string (str "(do " (slurp f) ")")))))"', repl_env);
 121
 122     if ~isempty(args)
 123         rep(strcat('(load-file "', args{1}, '")'), repl_env);
 124         quit;
 125     end
 126
 127     %cleanObj = onCleanup(@() disp('*** here1 ***'));
 128     while (true)
 129         line = input('user> ', 's');
 130         if strcmp(strtrim(line),''), continue, end
 131         try
 132             fprintf('%s\n', rep(line, repl_env));
 133         catch err
 134             fprintf('Error: %s\n', err.message);
 135             fprintf('%s\n', getReport(err, 'extended'));
 136         end
 137     end
 138 end