Merge branch 'master' into gh-pages

Conflicts:
	.gitignore

13 files changed, 65 insertions, 32 deletions

diff --git a/python/Makefile b/python/Makefile
index b461db3..7842eae 100644
--- a/python/Makefile
+++ b/python/Makefile
@@ -3,7 +3,7 @@ TESTS =
 
 
 SOURCES_BASE = mal_readline.py mal_types.py reader.py printer.py
-SOURCES_LISP = env.py core.py stepA_more.py
+SOURCES_LISP = env.py core.py stepA_mal.py
 SOURCES = $(SOURCES_BASE) $(SOURCES_LISP)
 
 
diff --git a/python/core.py b/python/core.py
index d10047d..4a64594 100644
--- a/python/core.py
+++ b/python/core.py
@@ -60,7 +60,9 @@ def cons(x, seq): return List([x]) + List(seq)
 
 def concat(*lsts): return List(chain(*lsts))
 
-def nth(lst, idx): return lst[idx]
+def nth(lst, idx):
+    if idx < len(lst): return lst[idx]
+    else: throw("nth: index out of range")
 
 def first(lst): return lst[0]
 
@@ -68,7 +70,9 @@ def rest(lst): return List(lst[1:])
 
 def empty_Q(lst): return len(lst) == 0
 
-def count(lst): return len(lst)
+def count(lst):
+    if types._nil_Q(lst): return 0
+    else: return len(lst)
 
 # retains metadata
 def conj(lst, *args):
@@ -114,6 +118,8 @@ ns = {
         'false?': types._false_Q,
         'symbol': types._symbol,
         'symbol?': types._symbol_Q,
+        'keyword': types._keyword,
+        'keyword?': types._keyword_Q,
 
         'pr-str': pr_str,
         'str': do_str,
diff --git a/python/mal_types.py b/python/mal_types.py
index e6bd70d..b1b1b3b 100644
--- a/python/mal_types.py
+++ b/python/mal_types.py
@@ -1,4 +1,15 @@
 import sys, copy, types as pytypes
+
+# python 3.0 differences
+if sys.hexversion > 0x3000000:
+    def u(x):
+        return x
+else:
+    import codecs
+    def u(x):
+        return codecs.unicode_escape_decode(x)[0]
+
+
 if sys.version_info[0] >= 3:
     str_types = [str]
 else:
@@ -58,6 +69,14 @@ class Symbol(str): pass
 def _symbol(str): return Symbol(str)
 def _symbol_Q(exp): return type(exp) == Symbol
 
+# Keywords
+# A specially prefixed string
+def _keyword(str):
+    if str[0] == u("\u029e"): return str
+    else:                     return u("\u029e") + str
+def _keyword_Q(exp):
+    return _string_Q(exp) and exp[0] == u("\u029e")
+
 # Functions
 def _function(Eval, Env, ast, env, params):
     def fn(*args):
diff --git a/python/printer.py b/python/printer.py
index 65bf256..98e3e90 100644
--- a/python/printer.py
+++ b/python/printer.py
@@ -12,7 +12,9 @@ def _pr_str(obj, print_readably=True):
             ret.extend((_pr_str(k), _pr_str(obj[k],_r)))
         return "{" + " ".join(ret) + "}"
     elif types._string_Q(obj):
-        if print_readably:
+        if len(obj) > 0 and obj[0] == types.u('\u029e'):
+            return ':' + obj[1:]
+        elif print_readably:
             return '"' + obj.encode('unicode_escape').decode('latin1').replace('"', '\\"') + '"'
         else:
             return obj
diff --git a/python/reader.py b/python/reader.py
index 13b1f7b..71ad3d6 100644
--- a/python/reader.py
+++ b/python/reader.py
@@ -1,5 +1,5 @@
 import re
-from mal_types import (_symbol, _list, _vector, _hash_map)
+from mal_types import (_symbol, _keyword, _list, _vector, _hash_map)
 
 class Blank(Exception): pass
 
@@ -29,6 +29,7 @@ def read_atom(reader):
     if re.match(int_re, token):     return int(token)
     elif re.match(float_re, token): return int(token)
     elif token[0] == '"':           return token[1:-1].replace('\\"', '"')
+    elif token[0] == ':':           return _keyword(token[1:])
     elif token == "nil":            return None
     elif token == "true":           return True
     elif token == "false":          return False
diff --git a/python/step3_env.py b/python/step3_env.py
index 4565011..86dc176 100644
--- a/python/step3_env.py
+++ b/python/step3_env.py
@@ -58,10 +58,10 @@ repl_env = Env()
 def REP(str):
     return PRINT(EVAL(READ(str), repl_env))
 
-repl_env.set('+', lambda a,b: a+b)
-repl_env.set('-', lambda a,b: a-b)
-repl_env.set('*', lambda a,b: a*b)
-repl_env.set('/', lambda a,b: int(a/b))
+repl_env.set(types._symbol('+'), lambda a,b: a+b)
+repl_env.set(types._symbol('-'), lambda a,b: a-b)
+repl_env.set(types._symbol('*'), lambda a,b: a*b)
+repl_env.set(types._symbol('/'), lambda a,b: int(a/b))
 
 # repl loop
 while True:
diff --git a/python/step4_if_fn_do.py b/python/step4_if_fn_do.py
index e99cfcf..39b9dd6 100644
--- a/python/step4_if_fn_do.py
+++ b/python/step4_if_fn_do.py
@@ -74,7 +74,7 @@ def REP(str):
     return PRINT(EVAL(READ(str), repl_env))
 
 # core.py: defined using python
-for k, v in core.ns.items(): repl_env.set(k, v)
+for k, v in core.ns.items(): repl_env.set(types._symbol(k), v)
 
 # core.mal: defined using the language itself
 REP("(def! not (fn* (a) (if a false true)))")
diff --git a/python/step5_tco.py b/python/step5_tco.py
index cbb92c9..da338d4 100644
--- a/python/step5_tco.py
+++ b/python/step5_tco.py
@@ -83,7 +83,7 @@ def REP(str):
     return PRINT(EVAL(READ(str), repl_env))
 
 # core.py: defined using python
-for k, v in core.ns.items(): repl_env.set(k, v)
+for k, v in core.ns.items(): repl_env.set(types._symbol(k), v)
 
 # core.mal: defined using the language itself
 REP("(def! not (fn* (a) (if a false true)))")
diff --git a/python/step6_file.py b/python/step6_file.py
index 9d84d1f..5d10b46 100644
--- a/python/step6_file.py
+++ b/python/step6_file.py
@@ -83,9 +83,9 @@ def REP(str):
     return PRINT(EVAL(READ(str), repl_env))
 
 # core.py: defined using python
-for k, v in core.ns.items(): repl_env.set(k, v)
-repl_env.set('eval', lambda ast: EVAL(ast, repl_env))
-repl_env.set('*ARGV*', types._list(*sys.argv[2:]))
+for k, v in core.ns.items(): repl_env.set(types._symbol(k), v)
+repl_env.set(types._symbol('eval'), lambda ast: EVAL(ast, repl_env))
+repl_env.set(types._symbol('*ARGV*'), types._list(*sys.argv[2:]))
 
 # core.mal: defined using the language itself
 REP("(def! not (fn* (a) (if a false true)))")
diff --git a/python/step7_quote.py b/python/step7_quote.py
index de19c6d..7c97c23 100644
--- a/python/step7_quote.py
+++ b/python/step7_quote.py
@@ -106,9 +106,9 @@ def REP(str):
     return PRINT(EVAL(READ(str), repl_env))
 
 # core.py: defined using python
-for k, v in core.ns.items(): repl_env.set(k, v)
-repl_env.set('eval', lambda ast: EVAL(ast, repl_env))
-repl_env.set('*ARGV*', types._list(*sys.argv[2:]))
+for k, v in core.ns.items(): repl_env.set(types._symbol(k), v)
+repl_env.set(types._symbol('eval'), lambda ast: EVAL(ast, repl_env))
+repl_env.set(types._symbol('*ARGV*'), types._list(*sys.argv[2:]))
 
 # core.mal: defined using the language itself
 REP("(def! not (fn* (a) (if a false true)))")
diff --git a/python/step8_macros.py b/python/step8_macros.py
index 80ca239..da863c1 100644
--- a/python/step8_macros.py
+++ b/python/step8_macros.py
@@ -126,9 +126,9 @@ def REP(str):
     return PRINT(EVAL(READ(str), repl_env))
 
 # core.py: defined using python
-for k, v in core.ns.items(): repl_env.set(k, v)
-repl_env.set('eval', lambda ast: EVAL(ast, repl_env))
-repl_env.set('*ARGV*', types._list(*sys.argv[2:]))
+for k, v in core.ns.items(): repl_env.set(types._symbol(k), v)
+repl_env.set(types._symbol('eval'), lambda ast: EVAL(ast, repl_env))
+repl_env.set(types._symbol('*ARGV*'), types._list(*sys.argv[2:]))
 
 # core.mal: defined using the language itself
 REP("(def! not (fn* (a) (if a false true)))")
diff --git a/python/step9_interop.py b/python/step9_try.py
index 7cacf1f..e01f42c 100644
--- a/python/step9_interop.py
+++ b/python/step9_try.py
@@ -97,12 +97,17 @@ def EVAL(ast, env):
             else:
                 exec(compile(ast[1], '', 'single') in globals())
             return None
-        elif "py*" == a0:
-            return eval(ast[1])
-        elif "." == a0:
-            el = eval_ast(ast[2:], env)
-            f = eval(ast[1])
-            return f(*el)
+        elif "try*" == a0:
+            a1, a2 = ast[1], ast[2]
+            if a2[0] == "catch*":
+                try:
+                    return EVAL(a1, env);
+                except Exception as exc:
+                    exc = exc.args[0]
+                    catch_env = Env(env, [a2[1]], [exc])
+                    return EVAL(a2[2], catch_env)
+            else:
+                return EVAL(a1, env);
         elif "do" == a0:
             eval_ast(ast[1:-1], env)
             ast = ast[-1]
@@ -138,9 +143,9 @@ def REP(str):
     return PRINT(EVAL(READ(str), repl_env))
 
 # core.py: defined using python
-for k, v in core.ns.items(): repl_env.set(k, v)
-repl_env.set('eval', lambda ast: EVAL(ast, repl_env))
-repl_env.set('*ARGV*', types._list(*sys.argv[2:]))
+for k, v in core.ns.items(): repl_env.set(types._symbol(k), v)
+repl_env.set(types._symbol('eval'), lambda ast: EVAL(ast, repl_env))
+repl_env.set(types._symbol('*ARGV*'), types._list(*sys.argv[2:]))
 
 # core.mal: defined using the language itself
 REP("(def! not (fn* (a) (if a false true)))")
diff --git a/python/stepA_more.py b/python/stepA_mal.py
index 723f0ed..93cdb2e 100644
--- a/python/stepA_more.py
+++ b/python/stepA_mal.py
@@ -149,9 +149,9 @@ def REP(str):
     return PRINT(EVAL(READ(str), repl_env))
 
 # core.py: defined using python
-for k, v in core.ns.items(): repl_env.set(k, v)
-repl_env.set('eval', lambda ast: EVAL(ast, repl_env))
-repl_env.set('*ARGV*', types._list(*sys.argv[2:]))
+for k, v in core.ns.items(): repl_env.set(types._symbol(k), v)
+repl_env.set(types._symbol('eval'), lambda ast: EVAL(ast, repl_env))
+repl_env.set(types._symbol('*ARGV*'), types._list(*sys.argv[2:]))
 
 # core.mal: defined using the language itself
 REP("(def! *host-language* \"python\")")