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     %fprintf('EVAL: %s\n', printer.pr_str(ast, true));
  38     if ~type_utils.list_Q(ast)
  39         ret = eval_ast(ast, env);
  40         return;
  41     end
  42
  43     % apply
  44     if length(ast) == 0
  45         ret = ast;
  46         return;
  47     end
  48     if isa(ast.get(1),'types.Symbol')
  49         a1sym = ast.get(1).name;
  50     else
  51         a1sym = '_@$fn$@_';
  52     end
  53     switch (a1sym)
  54     case 'def!'
  55         ret = env.set(ast.get(2), EVAL(ast.get(3), env));
  56         return;
  57     case 'let*'
  58         let_env = Env({env});
  59         for i=1:2:length(ast.get(2))
  60             let_env.set(ast.get(2).get(i), EVAL(ast.get(2).get(i+1), let_env));
  61         end
  62         env = let_env;
  63         ast = ast.get(3); % TCO
  64     case 'do'
  65         el = eval_ast(ast.slice(2,length(ast)-1), env);
  66         ast = ast.get(length(ast)); % TCO
  67     case 'if'
  68         cond = EVAL(ast.get(2), env);
  69         if strcmp(class(cond), 'types.Nil') || ...
  70            (islogical(cond) && cond == false)
  71            if length(ast) > 3
  72                ast = ast.get(4); % TCO
  73             else
  74                ret = type_utils.nil;
  75                return;
  76             end
  77         else
  78             ast = ast.get(3); % TCO
  79         end
  80     case 'fn*'
  81         fn = @(varargin) EVAL(ast.get(3), Env({env}, ast.get(2), ...
  82                                               types.List(varargin{:})));
  83         ret = types.Function(fn, ast.get(3), env, ast.get(2));
  84         return;
  85     otherwise
  86         el = eval_ast(ast, env);
  87         f = el.get(1);
  88         args = el.slice(2);
  89         if isa(f, 'types.Function')
  90             env = Env({f.env}, f.params, args);
  91             ast = f.ast; % TCO
  92         else
  93             ret = f(args.data{:});
  94             return
  95         end
  96     end
  97   end
  98 end
  99
 100 % print
 101 function ret = PRINT(ast)
 102     ret = printer.pr_str(ast, true);
 103 end
 104
 105 % REPL
 106 function ret = rep(str, env)
 107     ret = PRINT(EVAL(READ(str), env));
 108 end
 109
 110 function main(args)
 111     repl_env = Env();
 112
 113     % core.m: defined using matlab
 114     ns = core.ns(); ks = ns.keys();
 115     for i=1:length(ks)
 116         k = ks{i};
 117         repl_env.set(types.Symbol(k), ns(k));
 118     end
 119     repl_env.set(types.Symbol('eval'), @(a) EVAL(a, repl_env));
 120     rest_args = args(2:end);
 121     repl_env.set(types.Symbol('*ARGV*'), types.List(rest_args{:}));
 122
 123     % core.mal: defined using the langauge itself
 124     rep('(def! not (fn* (a) (if a false true)))', repl_env);
 125     rep('(def! load-file (fn* (f) (eval (read-string (str "(do " (slurp f) ")")))))"', repl_env);
 126
 127     if ~isempty(args)
 128         rep(sprintf('(load-file "%s")', args{1}), repl_env);
 129         quit;
 130     end
 131
 132     %cleanObj = onCleanup(@() disp('*** here1 ***'));
 133     while (true)
 134         try
 135             line = input('user> ', 's');
 136         catch err
 137             return
 138         end
 139         if strcmp(strtrim(line),''), continue, end
 140         try
 141             fprintf('%s\n', rep(line, repl_env));
 142         catch err
 143             fprintf('Error: %s\n', err.message);
 144             type_utils.print_stack(err);
 145         end
 146     end
 147 end