All: split types into types, env, printer, core.

- types: low-level mapping to the implementation language.
- core: functions on types that are exposed directly to mal.
- printer: implementation called by pr-str, str, prn, println.
- env: the environment implementation

- Also, unindent all TCO while loops so that the diff of step4 and
  step5 are minimized.

1 files changed, 85 insertions, 80 deletions

diff --git a/php/step9_interop.php b/php/step9_interop.php
index 26e89f0..a699109 100644
--- a/php/step9_interop.php
+++ b/php/step9_interop.php
@@ -3,6 +3,9 @@
 require_once 'readline.php';
 require_once 'types.php';
 require_once 'reader.php';
+require_once 'printer.php';
+require_once 'env.php';
+require_once 'core.php';
 
 // read
 function READ($str) {
@@ -11,27 +14,27 @@ function READ($str) {
 
 // eval
 function is_pair($x) {
-    return sequential_Q($x) and count($x) > 0;
+    return _sequential_Q($x) and count($x) > 0;
 }
 
 function quasiquote($ast) {
     if (!is_pair($ast)) {
-        return new_list(new_symbol("quote"), $ast);
-    } elseif (symbol_Q($ast[0]) && $ast[0]->value === 'unquote') {
+        return _list(_symbol("quote"), $ast);
+    } elseif (_symbol_Q($ast[0]) && $ast[0]->value === 'unquote') {
         return $ast[1];
-    } elseif (is_pair($ast[0]) && symbol_Q($ast[0][0]) &&
+    } elseif (is_pair($ast[0]) && _symbol_Q($ast[0][0]) &&
               $ast[0][0]->value === 'splice-unquote') {
-        return new_list(new_symbol("concat"), $ast[0][1],
-                        quasiquote($ast->slice(1)));
+        return _list(_symbol("concat"), $ast[0][1],
+                     quasiquote($ast->slice(1)));
     } else {
-        return new_list(new_symbol("cons"), quasiquote($ast[0]),
-                        quasiquote($ast->slice(1)));
+        return _list(_symbol("cons"), quasiquote($ast[0]),
+                     quasiquote($ast->slice(1)));
     }
 }
 
 function is_macro_call($ast, $env) {
     return is_pair($ast) &&
-           symbol_Q($ast[0]) &&
+           _symbol_Q($ast[0]) &&
            $env->find($ast[0]->value) &&
            $env->get($ast[0]->value)->ismacro;
 }
@@ -46,18 +49,18 @@ function macroexpand($ast, $env) {
 }
 
 function eval_ast($ast, $env) {
-    if (symbol_Q($ast)) {
+    if (_symbol_Q($ast)) {
         return $env->get($ast->value);
-    } elseif (list_Q($ast) || vector_Q($ast)) {
-        if (list_Q($ast)) {
-            $el = new_list();
+    } elseif (_sequential_Q($ast)) {
+        if (_list_Q($ast)) {
+            $el = _list();
         } else {
-            $el = new_vector();
+            $el = _vector();
         }
         foreach ($ast as $a) { $el[] = MAL_EVAL($a, $env); }
         return $el;
-    } elseif (hash_map_Q($ast)) {
-        $new_hm = new_hash_map();
+    } elseif (_hash_map_Q($ast)) {
+        $new_hm = _hash_map();
         foreach (array_keys($ast->getArrayCopy()) as $key) {
             $new_hm[$key] = MAL_EVAL($ast[$key], $env);
         }
@@ -69,69 +72,71 @@ function eval_ast($ast, $env) {
 
 function MAL_EVAL($ast, $env) {
     while (true) {
-        #echo "MAL_EVAL: " . _pr_str($ast) . "\n";
-        if (!list_Q($ast)) {
-            return eval_ast($ast, $env);
-        }
 
-        // apply list
-        $ast = macroexpand($ast, $env);
-        if (!list_Q($ast)) { return $ast; }
-
-        $a0 = $ast[0];
-        $a0v = (symbol_Q($a0) ? $a0->value : $a0);
-        switch ($a0v) {
-        case "def!":
-            $res = MAL_EVAL($ast[2], $env);
-            return $env->set($ast[1]->value, $res);
-        case "let*":
-            $a1 = $ast[1];
-            $let_env = new Env($env);
-            for ($i=0; $i < count($a1); $i+=2) {
-                $let_env->set($a1[$i]->value, MAL_EVAL($a1[$i+1], $let_env));
-            }
-            return MAL_EVAL($ast[2], $let_env);
-        case "quote":
-            return $ast[1];
-        case "quasiquote":
-            return MAL_EVAL(quasiquote($ast[1]), $env);
-        case "defmacro!":
-            $func = MAL_EVAL($ast[2], $env);
-            $func->ismacro = true;
-            return $env->set($ast[1]->value, $func);
-        case "macroexpand":
-            return macroexpand($ast[1], $env);
-        case "php*":
-            return eval($ast[1]);
-        case "do":
-            eval_ast($ast->slice(1, -1), $env);
-            $ast = $ast[count($ast)-1];
-            break;
-        case "if":
-            $cond = MAL_EVAL($ast[1], $env);
-            if ($cond === NULL || $cond === false) {
-                if (count($ast) === 4) { $ast = $ast[3]; }
-                else                   { $ast = NULL; }
-            } else {
-                $ast = $ast[2];
-            }
-            break;
-        case "fn*":
-            return new_function('MAL_EVAL', 'native',
-                                new_hash_map('exp', $ast[2],
-                                             'env', $env,
-                                             'params', $ast[1]));
-        default:
-            $el = eval_ast($ast, $env);
-            $f = $el[0];
-            $args = array_slice($el->getArrayCopy(), 1);
-            if ($f->type === 'native') {
-                $ast = $f->meta['exp'];
-                $env = new Env($f->meta['env'], $f->meta['params'], $args);
-            } else {
-                return $f->apply($args);
-            }
+    #echo "MAL_EVAL: " . _pr_str($ast) . "\n";
+    if (!_list_Q($ast)) {
+        return eval_ast($ast, $env);
+    }
+
+    // apply list
+    $ast = macroexpand($ast, $env);
+    if (!_list_Q($ast)) { return $ast; }
+
+    $a0 = $ast[0];
+    $a0v = (_symbol_Q($a0) ? $a0->value : $a0);
+    switch ($a0v) {
+    case "def!":
+        $res = MAL_EVAL($ast[2], $env);
+        return $env->set($ast[1]->value, $res);
+    case "let*":
+        $a1 = $ast[1];
+        $let_env = new Env($env);
+        for ($i=0; $i < count($a1); $i+=2) {
+            $let_env->set($a1[$i]->value, MAL_EVAL($a1[$i+1], $let_env));
         }
+        return MAL_EVAL($ast[2], $let_env);
+    case "quote":
+        return $ast[1];
+    case "quasiquote":
+        return MAL_EVAL(quasiquote($ast[1]), $env);
+    case "defmacro!":
+        $func = MAL_EVAL($ast[2], $env);
+        $func->ismacro = true;
+        return $env->set($ast[1]->value, $func);
+    case "macroexpand":
+        return macroexpand($ast[1], $env);
+    case "php*":
+        return eval($ast[1]);
+    case "do":
+        eval_ast($ast->slice(1, -1), $env);
+        $ast = $ast[count($ast)-1];
+        break;
+    case "if":
+        $cond = MAL_EVAL($ast[1], $env);
+        if ($cond === NULL || $cond === false) {
+            if (count($ast) === 4) { $ast = $ast[3]; }
+            else                   { $ast = NULL; }
+        } else {
+            $ast = $ast[2];
+        }
+        break;
+    case "fn*":
+        return _function('MAL_EVAL', 'native',
+                         _hash_map('exp', $ast[2],
+                                   'env', $env,
+                                   'params', $ast[1]));
+    default:
+        $el = eval_ast($ast, $env);
+        $f = $el[0];
+        $args = array_slice($el->getArrayCopy(), 1);
+        if ($f->type === 'native') {
+            $ast = $f->meta['exp'];
+            $env = new Env($f->meta['env'], $f->meta['params'], $args);
+        } else {
+            return $f->apply($args);
+        }
+    }
+
     }
 }
 
@@ -148,10 +153,10 @@ function rep($str) {
 }
 function _ref($k, $v) {
     global $repl_env;
-    $repl_env->set($k, new_function($v));
+    $repl_env->set($k, _function($v));
 }
-// Import types functions
-foreach ($types_ns as $k=>$v) { _ref($k, $v); }
+// Import core functions
+foreach ($core_ns as $k=>$v) { _ref($k, $v); }
 
 _ref('read-string', 'read_str');
 _ref('eval', function($ast) {