matlab: step7, fix reader bug.

3 files changed, 175 insertions, 1 deletions

diff --git a/matlab/core.m b/matlab/core.m
index fb6e456..4115b2c 100644
--- a/matlab/core.m
+++ b/matlab/core.m
@@ -23,6 +23,14 @@ classdef core
             ret = types.nil;
         end
 
+        function ret = concat(varargin)
+            if nargin == 0
+                ret = {};
+            else
+                ret = cat(2,varargin{:});
+            end
+        end
+
         function n = ns()
             n = containers.Map();
             n('=') =  @types.equal;
@@ -45,6 +53,9 @@ classdef core
 
             n('list') = @(varargin) varargin;
             n('list?') = @iscell;
+
+            n('cons') = @(a,b) [{a}, b];
+            n('concat') = @core.concat;
             n('empty?') = @(a) length(a) == 0;
             n('count') = @(a) length(a);
         end
diff --git a/matlab/reader.m b/matlab/reader.m
index 7053aef..968e5a1 100644
--- a/matlab/reader.m
+++ b/matlab/reader.m
@@ -49,7 +49,19 @@ classdef reader
         function ast = read_form(rdr)
             %fprintf('in read_form\n');
             token = rdr.peek();
-            switch token(1)
+            switch token
+            case ''''
+                rdr.next();
+                ast = {types.Symbol('quote'), reader.read_form(rdr)};
+            case '`'
+                rdr.next();
+                ast = {types.Symbol('quasiquote'), reader.read_form(rdr)};
+            case '~'
+                rdr.next();
+                ast = {types.Symbol('unquote'), reader.read_form(rdr)};
+            case '~@'
+                rdr.next();
+                ast = {types.Symbol('splice-unquote'), reader.read_form(rdr)};
             case ')'
                 error('unexpected '')''');
             case '('
diff --git a/matlab/step7_quote.m b/matlab/step7_quote.m
new file mode 100644
index 0000000..eaace83
--- /dev/null
+++ b/matlab/step7_quote.m
@@ -0,0 +1,151 @@
+function step7_quote(varargin), main(varargin), end
+
+% read
+function ret = READ(str)
+    ret = reader.read_str(str);
+end
+
+% eval
+function ret = is_pair(ast)
+    ret = isa(ast, 'cell') && length(ast) > 0;
+end
+
+function ret = quasiquote(ast)
+    if ~is_pair(ast)
+        ret = {types.Symbol('quote'), ast};
+    elseif isa(ast{1},'types.Symbol') && ...
+           strcmp(ast{1}.name, 'unquote')
+        ret = ast{2};
+    elseif is_pair(ast{1}) && isa(ast{1}{1},'types.Symbol') && ...
+           strcmp(ast{1}{1}.name, 'splice-unquote')
+        ret = {types.Symbol('concat'), ...
+               ast{1}{2}, ...
+               quasiquote(ast(2:end))};
+    else
+        ret = {types.Symbol('cons'), ...
+               quasiquote(ast{1}), ...
+               quasiquote(ast(2:end))};
+    end
+end
+
+function ret = eval_ast(ast, env)
+    switch class(ast)
+    case 'types.Symbol'
+        ret = env.get(ast);
+    case 'cell'
+        ret = {};
+        for i=1:length(ast)
+            ret{end+1} = EVAL(ast{i}, env);
+        end
+    otherwise
+        ret = ast;
+    end
+end
+
+function ret = EVAL(ast, env)
+  while true
+    if ~iscell(ast)
+        ret = eval_ast(ast, env);
+        return;
+    end
+
+    % apply
+    if isa(ast{1},'types.Symbol')
+        a1sym = ast{1}.name;
+    else
+        a1sym = '_@$fn$@_';
+    end
+    switch (a1sym)
+    case 'def!'
+        ret = env.set(ast{2}, EVAL(ast{3}, env));
+        return;
+    case 'let*'
+        let_env = Env(env);
+        for i=1:2:length(ast{2})
+            let_env.set(ast{2}{i}, EVAL(ast{2}{i+1}, let_env));
+        end
+        env = let_env;
+        ast = ast{3}; % TCO
+    case 'quote'
+        ret = ast{2};
+        return;
+    case 'quasiquote'
+        ast = quasiquote(ast{2}); % TCO
+    case 'do'
+        el = eval_ast(ast(2:end-1), env);
+        ast = ast{end}; % TCO
+    case 'if'
+        cond = EVAL(ast{2}, env);
+        if strcmp(class(cond), 'types.Nil') || ...
+           (islogical(cond) && cond == false)
+           if length(ast) > 3
+               ast = ast{4}; % TCO
+            else
+               ret = types.nil;
+               return;
+            end
+        else
+            ast = ast{3}; % TCO
+        end
+    case 'fn*'
+        fn = @(varargin) EVAL(ast{3}, Env(env, ast{2}, varargin));
+        ret = Function(fn, ast{3}, env, ast{2});
+        return;
+    otherwise
+        el = eval_ast(ast, env);
+        f = el{1};
+        args = el(2:end);
+        if isa(f, 'Function')
+            env = Env(f.env, f.params, args);
+            ast = f.ast; % TCO
+        else
+            ret = f(args{:});
+            return
+        end
+    end
+  end
+end
+
+% print
+function ret = PRINT(ast)
+    ret = printer.pr_str(ast, true);
+end
+
+% REPL
+function ret = rep(str, env)
+    ret = PRINT(EVAL(READ(str), env));
+end
+
+function main(args)
+    repl_env = Env(false);
+
+    % core.m: defined using matlab
+    ns = core.ns(); ks = ns.keys();
+    for i=1:length(ks)
+        k = ks{i};
+        repl_env.set(types.Symbol(k), ns(k));
+    end
+    repl_env.set(types.Symbol('eval'), @(a) EVAL(a, repl_env));
+    repl_env.set(types.Symbol('*ARGV*'), args(2:end));
+
+    % core.mal: defined using the langauge itself
+    rep('(def! not (fn* (a) (if a false true)))', repl_env);
+    rep('(def! load-file (fn* (f) (eval (read-string (str "(do " (slurp f) ")")))))"', repl_env);
+
+    if ~isempty(args)
+        rep(strcat('(load-file "', args{1}, '")'), repl_env);
+        quit;
+    end
+
+    %cleanObj = onCleanup(@() disp('*** here1 ***'));
+    while (true)
+        line = input('user> ', 's');
+        if strcmp(strtrim(line),''), continue, end
+        try
+            fprintf('%s\n', rep(line, repl_env));
+        catch err
+            fprintf('Error: %s\n', err.message);
+            fprintf('%s\n', getReport(err, 'extended'));
+        end
+    end
+end