From 3169070063b2cb877200117ebb384269d73bcb93 Mon Sep 17 00:00:00 2001 From: Joel Martin Date: Mon, 24 Mar 2014 16:32:24 -0500 Subject: Current state of mal for Clojure West lighting talk. --- python/step9_interop.py | 154 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 154 insertions(+) create mode 100644 python/step9_interop.py (limited to 'python/step9_interop.py') diff --git a/python/step9_interop.py b/python/step9_interop.py new file mode 100644 index 0000000..3a20960 --- /dev/null +++ b/python/step9_interop.py @@ -0,0 +1,154 @@ +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) + +# read +def READ(str): + return read_str(str) + +# eval +def is_pair(x): + return sequential_Q(x) and len(x) > 0 + +def quasiquote(ast): + if not is_pair(ast): + return new_list(new_symbol("quote"), ast) + elif ast[0] == 'unquote': + return ast[1] + elif is_pair(ast[0]) and ast[0][0] == 'splice-unquote': + return new_list(new_symbol("concat"), ast[0][1], quasiquote(ast[1:])) + else: + return new_list(new_symbol("cons"), quasiquote(ast[0]), quasiquote(ast[1:])) + +def is_macro_call(ast, env): + return (list_Q(ast) and + symbol_Q(ast[0]) and + env.find(ast[0]) and + hasattr(env.get(ast[0]), '_ismacro_')) + +def macroexpand(ast, env): + while is_macro_call(ast, env): + mac = env.get(ast[0]) + ast = macroexpand(mac(*ast[1:]), env) + return ast + +def eval_ast(ast, env): + if 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): + keyvals = [] + for k in ast.keys(): + keyvals.append(EVAL(k, env)) + keyvals.append(EVAL(ast[k], env)) + return new_hash_map(*keyvals) + else: + return ast # primitive value, return unchanged + +def EVAL(ast, env): + while True: + #print("EVAL %s" % ast) + if not list_Q(ast): + return eval_ast(ast, env) + + # apply list + ast = macroexpand(ast, env) + if not list_Q(ast): return ast + 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) + elif "quote" == a0: + return ast[1] + elif "quasiquote" == a0: + return EVAL(quasiquote(ast[1]), env) + elif 'defmacro!' == a0: + func = EVAL(ast[2], env) + func._ismacro_ = True + return env.set(ast[1], func) + elif 'macroexpand' == a0: + return macroexpand(ast[1], env) + elif "py!*" == a0: + 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 "do" == a0: + eval_ast(ast[1:-1], env) + ast = ast[-1] + # Continue loop (TCO) + elif "if" == a0: + a1, a2 = ast[1], ast[2] + cond = EVAL(a1, env) + if cond is None or cond is False: + if len(ast) > 3: ast = ast[3] + else: ast = None + else: + ast = a2 + # Continue loop (TCO) + elif "fn*" == a0: + a1, a2 = ast[1], ast[2] + return new_function(EVAL, a2, env, a1) + else: + el = eval_ast(ast, env) + f = el[0] + if hasattr(f, '__meta__') and f.__meta__.has_key("exp"): + m = f.__meta__ + ast = m['exp'] + env = Env(m['env'], m['params'], el[1:]) + else: + return f(*el[1:]) + +# print +def PRINT(exp): + return pr_str(exp) + +# repl +repl_env = Env() +def REP(str): + return PRINT(EVAL(READ(str), repl_env)) +def _ref(k,v): repl_env.set(k, v) + +# Import types functions +for name, val in types_ns.items(): _ref(name, val) + +_ref('read-string', read_str) +_ref('eval', lambda ast: EVAL(ast, repl_env)) +_ref('slurp', lambda file: open(file).read()) +_ref('slurp-do', lambda file: "(do" + open(file).read() + ")") + +# Defined using the language itself +REP("(def! not (fn* (a) (if a false true)))") +REP("(def! load-file (fn* (f) (eval (read-string (slurp-do f)))))") + +if len(sys.argv) >= 2: + REP('(load-file "' + sys.argv[1] + '")') +else: + while True: + try: + line = mal_readline.readline("user> ") + if line == None: break + if line == "": continue + print(REP(line)) + except Blank: continue + except Exception as e: + print "".join(traceback.format_exception(*sys.exc_info())) -- cgit v1.2.3