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, 33 insertions, 34 deletions

diff --git a/python/step3_env.py b/python/step3_env.py
index f95a978..21879d6 100644
--- a/python/step3_env.py
+++ b/python/step3_env.py
@@ -1,58 +1,57 @@
 import sys, traceback
 import mal_readline
-from mal_types import (pr_str, sequential_Q, symbol_Q, coll_Q, list_Q,
-                       vector_Q, hash_map_Q, new_symbol, new_function,
-                       new_list, new_vector, new_hash_map, Env, types_ns)
-from reader import (read_str, Blank)
+import mal_types as types
+import reader, printer
+from env import Env
 
 # read
 def READ(str):
-    return read_str(str)
+    return reader.read_str(str)
 
 # eval
 def eval_ast(ast, env):
-    if symbol_Q(ast):
+    if types._symbol_Q(ast):
         return env.get(ast)
-    elif list_Q(ast):
-        return new_list(*map(lambda a: EVAL(a, env), ast))
-    elif vector_Q(ast):
-        return new_vector(*map(lambda a: EVAL(a, env), ast))
-    elif hash_map_Q(ast):
+    elif types._list_Q(ast):
+        return types._list(*map(lambda a: EVAL(a, env), ast))
+    elif types._vector_Q(ast):
+        return types._vector(*map(lambda a: EVAL(a, env), ast))
+    elif types._hash_map_Q(ast):
         keyvals = []
         for k in ast.keys():
             keyvals.append(EVAL(k, env))
             keyvals.append(EVAL(ast[k], env))
-        return new_hash_map(*keyvals)
+        return types._hash_map(*keyvals)
     else:
         return ast  # primitive value, return unchanged
 
 def EVAL(ast, env):
-    #print("EVAL %s" % ast)
-    if not list_Q(ast):
-        return eval_ast(ast, env)
+        #print("EVAL %s" % ast)
+        if not types._list_Q(ast):
+            return eval_ast(ast, env)
 
-    # apply list
-    if len(ast) == 0: return ast
-    a0 = ast[0]
+        # apply list
+        if len(ast) == 0: return ast
+        a0 = ast[0]
 
-    if "def!" == a0:
-        a1, a2 = ast[1], ast[2]
-        res = EVAL(a2, env)
-        return env.set(a1, res)
-    elif "let*" == a0:
-        a1, a2 = ast[1], ast[2]
-        let_env = Env(env)
-        for i in range(0, len(a1), 2):
-            let_env.set(a1[i], EVAL(a1[i+1], let_env))
-        return EVAL(a2, let_env)
-    else:
-        el = eval_ast(ast, env)
-        f = el[0]
-        return f(*el[1:])
+        if "def!" == a0:
+            a1, a2 = ast[1], ast[2]
+            res = EVAL(a2, env)
+            return env.set(a1, res)
+        elif "let*" == a0:
+            a1, a2 = ast[1], ast[2]
+            let_env = Env(env)
+            for i in range(0, len(a1), 2):
+                let_env.set(a1[i], EVAL(a1[i+1], let_env))
+            return EVAL(a2, let_env)
+        else:
+            el = eval_ast(ast, env)
+            f = el[0]
+            return f(*el[1:])
 
 # print
 def PRINT(exp):
-    return pr_str(exp)
+    return printer._pr_str(exp)
 
 # repl
 repl_env = Env()
@@ -71,6 +70,6 @@ while True:
         if line == None: break
         if line == "": continue
         print(REP(line))
-    except Blank: continue
+    except reader.Blank: continue
     except Exception as e:
         print "".join(traceback.format_exception(*sys.exc_info()))