def find(self, name):
"""
沿着作用于链查找name的value
"""
try:
return self[name] if (name in self._dict) else self.outer.find(name)
except AttributeError as e:
print(colorful('{0} 在作用域链上不存在!'.format(name), 'Red'))
return 'not-define-yet'
def find(self, name):
"""
沿着作用于链查找name的value
"""
try:
return self[name] if (name
in self._dict) else self.outer.find(name)
except AttributeError as e:
print(colorful('{0} 在作用域链上不存在!'.format(name), 'Red'))
return 'not-define-yet'
def calc_value(self, env=Env.std_env()):
"""
在指定环境中求值, 或者对环境造成改变
:param env: 表达式所在环境
:return:表达式的值
"""
if self.static and self.value:
print(colorful('静态表达式, 直接返回值', 'Bold'))
return self.value
res = None
stype, child = self.stype, self.child
if stype == 'number':
res = child[0].calc_value(env)
elif stype == 'integer':
res = int(self._value)
elif stype == 'decimal':
res = float(self._value)
elif stype == 'string':
res = self._value
elif stype == 'bool':
res = True if self._value == '$T' else False
elif stype == 'symbol':
self._value = child[0].raw_value
res = child[0].calc_value(env)
elif stype == 'identifier':
res = env.find(self._value)
elif stype == 'op':
res = env.find(self._value)
elif stype == 'atom' or self.stype == 'func':
res = child[0].calc_value(env)
elif stype == 'lexp':
res = child[0].calc_value(env)
if child[0].stype == 'list':
res = [res, ]
res = args_restore(res)
elif stype == 'lexp-seq':
if len(child) > 1:
res = (child[0].calc_value(env), ) + child[1].calc_value(env)
else:
res = (child[0].calc_value(env), )
# print 'this lexp-seq:', res
elif stype == 'list':
if len(child) == 3:
res = child[1].calc_value(env)
else:
res = tuple()
elif stype == 's-exp':
func = child[1].calc_value(env)
args = child[2].calc_value(env)
if len(child) == 3:
res = func()
else:
res = func(*[args_restore(arg) for arg in args])
elif stype == 'define-exp':
# <define-exp> ::= <(> <define> <symbol> <lexp> <)>
symbol = child[2].child[0].raw_value
define(env, symbol, child[3])
res = symbol
elif stype == 'args':
if child[0].stype == 'symbol':
res = (child[0].child[0].raw_value, )
else:
res = child[0].calc_value(env) + (child[1].child[0].raw_value, )
elif stype == 'proc-body':
if len(child) <= 1:
res = child[0].calc_value(env)
else:
# 用语句块的最后一个语句作为语句块的值
_ = child[0].calc_value(env)
res = child[1].calc_value(env)
elif stype == 'lambda-exp':
# <lambda-exp> ::= <(> <lambda> <(> <args> <)> <proc-body> <)>
args = child[3].calc_value(env)
body = child[5]
# print 'args: ', args
# print 'body:', body
res = Procedure(args, body, env)
elif stype == 'var-exps':
if len(child) == 4:
define(env, child[1].child[0].raw_value, child[2])
else:
child[0].calc_value(env)
define(env, child[2].child[0].raw_value, child[3])
elif stype == 'let-exp':
# <let-exp> ::= <(> <let> <(> <var-exps> <)> <proc-body> <)
let_env = Env.std_env(outer=env)
child[3].calc_value(let_env)
res = child[5].calc_value(let_env)
elif stype == 'proc-define-exp':
# <proc-define-exp> ::= <(> <define> <(> <symbol> <args> <)> <proc-body> <)>
# <proc-define-exp> ::= <(> <define> <(> <symbol> <)> <proc-body> <)>
if len(child) > 7:
# 有参函数
symbol = child[3].child[0].raw_value
args = child[4].calc_value(env)
body = child[6]
proc = Procedure(args, body, env)
env[symbol] = proc
else:
symbol = child[3].child[0].raw_value
args = tuple()
body = child[5]
proc = Procedure(args, body, env)
env[symbol] = proc
if symbol in env.dynamic_bind:
# 如果之前是动态绑定key, 移除
del env.dynamic_bind[symbol]
res = symbol
elif stype == 'predicate':
if child[0].calc_value(env):
res = True
else:
res = False
elif stype in ['consequent', 'alternate']:
res = child[0].calc_value(env)
elif stype == 'if-exp':
# <if-exp> ::= <(> <if> <predicate> <consequent> <alternate> <)>
if child[2].calc_value(env):
res = child[3].calc_value(env)
else:
res = child[4].calc_value(env)
elif stype == 'or-exp':
# <or-exp> ::= <(> <or> <lexp-seq> <)>
cnode = child[2]
res = False
while len(cnode.child) > 1:
val = cnode.child[0].calc_value(env)
if type(val) == list:
val = args_restore(val)
if val:
res = val
break
else:
cnode = cnode.child[1]
else:
val = cnode.calc_value(env)[0]
if type(val) == list:
val = args_restore(val)
if val:
res = val
elif stype == 'and-exp':
# <and-exp> ::= <(> <and> <lexp-seq> <)>
cnode = child[2]
res = True
while len(cnode.child) > 1:
val = cnode.child[0].calc_value(env)
if type(val) == list:
val = args_restore(val)
if not val:
res = val
break
else:
cnode = cnode.child[1]
else:
val = cnode.calc_value(env)[0]
if type(val) == list:
val = args_restore(val)
if not val:
res = val
if not self.static:
self.value = res
return res
def reduce(self, grammar):
"""
规约动作, grammar为规约用的产身世
"""
print('利用规则' + colorful('%s -> %s' % (grammar[0], ' '.join(grammar[1])), "Green"))
def shift(self, token):
print(colorful('移近 {0} {1}'.format(token[0], token[1]), "Cyan"))
def compile(self):
"""
利用 self.grammar 编译出dfa, 并构造分析表
:return:
"""
self.calc_first()
alloc = 0
grammar = self.grammar
dfa = DFA()
que = Queue()
dfa.start = DFANode(id=alloc,
lr_items=self.closure(("start", tuple(),
tuple(grammar["start"][0]),
{'$'})))
self.idx_items = [dfa.start]
que.put(dfa.start.lr_items)
vis = dict()
vis[frozen_items(dfa.start.lr_items)] = dfa.start
while not que.empty():
lr_items = que.get()
# if frozen_items(lr_items) in vis:
# continue
dfa_node = vis[frozen_items(lr_items)]
# print 'u_items:'
# print lr_items
tmp = defaultdict(list)
for item in lr_items:
if item[2]:
u_item = (item[0], item[1] + item[2][:1],
item[2][1:], item[3])
tmp[item[2][0]].append(u_item)
# 可能该状态有两个以上项目可以通过 item[2][0] 转换到新项目, 而新的项目集应该是他们的合集
for l_hand, items in tmp.iteritems():
vitem = defaultdict(set)
for item in items:
u_items = self.closure(item)
for u_item in u_items:
vitem[u_item[:-1]].update(u_item[3])
next_items = [core + (head, )
for core, head in vitem.iteritems()]
if frozen_items(next_items) not in vis:
que.put(next_items)
alloc += 1
dfa_node.next[l_hand] = DFANode(id=alloc,
lr_items=next_items)
self.idx_items.append(dfa_node.next[l_hand]) # 插入新节点
vis[frozen_items(next_items)] = dfa_node.next[l_hand]
else:
dfa_node.next[l_hand] = vis[frozen_items(next_items)]
# dfa.draw("LR", show_meta=["lr_items"], generate_id=False)
self.lr_dfa = dfa
# DFA 构造完成
# 构造分析表
lr_table = defaultdict(dict)
que = Queue()
que.put(dfa.start)
vis = dict()
while not que.empty():
tmp = que.get()
if tmp in vis:
continue
vis[tmp] = 1
for item in tmp.lr_items:
if item[2]:
# 移进状态
if item[2][0] in lr_table[tmp.id]:
if lr_table[tmp.id][item[2][0]]['action'] != 'shift':
print(colorful('移近规约冲突', 'Red'))
raise LRConflict()
elif lr_table[tmp.id][item[2][0]]['next'] != \
tmp.next[item[2][0]].id:
print(colorful('移近移近冲突', 'Red'))
raise LRConflict()
lr_table[tmp.id][item[2][0]] = \
dict(action="shift", next=tmp.next[item[2][0]].id)
else:
# 规约状态
for a in item[3]:
if a in lr_table[tmp.id]:
if lr_table[tmp.id][a]['action'] != 'reduce':
print(colorful('移近规约冲突', 'Red'))
raise LRConflict()
elif lr_table[tmp.id][a]['grammar'] != item:
print(colorful('规约规约冲突', 'Red'))
raise LRConflict()
lr_table[tmp.id][a] = dict(action="reduce",
grammar=item)
for next_node in tmp.next.values():
que.put(next_node)
self.lr_table = lr_table
return dfa
class ParseHandler(object):
def __init__(self):
self.ast = None
self.exps = []
def shift(self, token):
print(colorful('移近 {0} {1}'.format(token[0], token[1]), "Cyan"))
def reduce(self, grammar):
"""
规约动作, grammar为规约用的产身世
"""
print('利用规则' + colorful('%s -> %s' % (grammar[0], ' '.join(grammar[1])), "Green"))
# from util import colorful
lex = Lex()
lex.keyword = ['lambda', '[', ']', 'let', 'define', 'if', 'cond', 'or', 'and', '(', ')']
lex.read_lex('regular_lex.txt')
lex.compile(grammar_type="regular")
print(colorful('词法编译完成...', 'Yellow'))
parser = LRParser()
parser.read_grammar('schepy_grammar.txt')
parser.compile()
print(colorful('语法编译完成...', 'Yellow'))
parser.show_dfa()
while True:
parser.parse(lex.lex(raw_input(), ignore=["limit"]), ParseHandler())
crash_on_ipy.init()
from lex import Lex
from parser import LRParser
from util import colorful
from runtime import ParseHandler, Env
LEX = Lex()
LEX.keyword = ['lambda', '[', ']', 'let', 'define', 'if',
'cond', 'or', 'and', '(', ')', '$T', '$F']
LEX.read_lex('regular_lex.txt')
LEX.compile(grammar_type="regular")
# lex.read_lex('regex_lex.txt')
# lex.compile()
print(colorful('词法编译完成...', 'Yellow'))
PARSER = LRParser()
PARSER.read_grammar('schepy_grammar.txt')
PARSER.compile()
print(colorful('语法编译完成...', 'Yellow'))
GLOBAL_ENV = Env.std_env()
while True:
try:
HANDLER = ParseHandler()
EXP = raw_input(colorful('schepy => ', 'Cyan'))
PARSER.parse(LEX.lex(EXP, ignore=["limit"]), HANDLER)
print(';VALUE: ' +
colorful(repr(HANDLER.ast.calc_value(env=GLOBAL_ENV)), "Magenta"))
except (EOFError, KeyboardInterrupt) as e:
CHOICE = raw_input(colorful('Do you really want to exit ([y]/n)?',
"Red"))
def calc_value(self, env=Env.std_env()):
"""
在指定环境中求值, 或者对环境造成改变
:param env: 表达式所在环境
:return:表达式的值
"""
if self.static and self.value:
print(colorful('静态表达式, 直接返回值', 'Bold'))
return self.value
res = None
stype, child = self.stype, self.child
if stype == 'number':
res = child[0].calc_value(env)
elif stype == 'integer':
res = int(self._value)
elif stype == 'decimal':
res = float(self._value)
elif stype == 'string':
res = self._value
elif stype == 'bool':
res = True if self._value == '$T' else False
elif stype == 'symbol':
self._value = child[0].raw_value
res = child[0].calc_value(env)
elif stype == 'identifier':
res = env.find(self._value)
elif stype == 'op':
res = env.find(self._value)
elif stype == 'atom' or self.stype == 'func':
res = child[0].calc_value(env)
elif stype == 'lexp':
res = child[0].calc_value(env)
if child[0].stype == 'list':
res = [
res,
]
res = args_restore(res)
elif stype == 'lexp-seq':
if len(child) > 1:
res = (child[0].calc_value(env), ) + child[1].calc_value(env)
else:
res = (child[0].calc_value(env), )
# print 'this lexp-seq:', res
elif stype == 'list':
if len(child) == 3:
res = child[1].calc_value(env)
else:
res = tuple()
elif stype == 's-exp':
func = child[1].calc_value(env)
args = child[2].calc_value(env)
if len(child) == 3:
res = func()
else:
res = func(*[args_restore(arg) for arg in args])
elif stype == 'define-exp':
# <define-exp> ::= <(> <define> <symbol> <lexp> <)>
symbol = child[2].child[0].raw_value
define(env, symbol, child[3])
res = symbol
elif stype == 'args':
if child[0].stype == 'symbol':
res = (child[0].child[0].raw_value, )
else:
res = child[0].calc_value(env) + (
child[1].child[0].raw_value, )
elif stype == 'proc-body':
if len(child) <= 1:
res = child[0].calc_value(env)
else:
# 用语句块的最后一个语句作为语句块的值
_ = child[0].calc_value(env)
res = child[1].calc_value(env)
elif stype == 'lambda-exp':
# <lambda-exp> ::= <(> <lambda> <(> <args> <)> <proc-body> <)>
args = child[3].calc_value(env)
body = child[5]
# print 'args: ', args
# print 'body:', body
res = Procedure(args, body, env)
elif stype == 'var-exps':
if len(child) == 4:
define(env, child[1].child[0].raw_value, child[2])
else:
child[0].calc_value(env)
define(env, child[2].child[0].raw_value, child[3])
elif stype == 'let-exp':
# <let-exp> ::= <(> <let> <(> <var-exps> <)> <proc-body> <)
let_env = Env.std_env(outer=env)
child[3].calc_value(let_env)
res = child[5].calc_value(let_env)
elif stype == 'proc-define-exp':
# <proc-define-exp> ::= <(> <define> <(> <symbol> <args> <)> <proc-body> <)>
# <proc-define-exp> ::= <(> <define> <(> <symbol> <)> <proc-body> <)>
if len(child) > 7:
# 有参函数
symbol = child[3].child[0].raw_value
args = child[4].calc_value(env)
body = child[6]
proc = Procedure(args, body, env)
env[symbol] = proc
else:
symbol = child[3].child[0].raw_value
args = tuple()
body = child[5]
proc = Procedure(args, body, env)
env[symbol] = proc
if symbol in env.dynamic_bind:
# 如果之前是动态绑定key, 移除
del env.dynamic_bind[symbol]
res = symbol
elif stype == 'predicate':
if child[0].calc_value(env):
res = True
else:
res = False
elif stype in ['consequent', 'alternate']:
res = child[0].calc_value(env)
elif stype == 'if-exp':
# <if-exp> ::= <(> <if> <predicate> <consequent> <alternate> <)>
if child[2].calc_value(env):
res = child[3].calc_value(env)
else:
res = child[4].calc_value(env)
elif stype == 'or-exp':
# <or-exp> ::= <(> <or> <lexp-seq> <)>
cnode = child[2]
res = False
while len(cnode.child) > 1:
val = cnode.child[0].calc_value(env)
if type(val) == list:
val = args_restore(val)
if val:
res = val
break
else:
cnode = cnode.child[1]
else:
val = cnode.calc_value(env)[0]
if type(val) == list:
val = args_restore(val)
if val:
res = val
elif stype == 'and-exp':
# <and-exp> ::= <(> <and> <lexp-seq> <)>
cnode = child[2]
res = True
while len(cnode.child) > 1:
val = cnode.child[0].calc_value(env)
if type(val) == list:
val = args_restore(val)
if not val:
res = val
break
else:
cnode = cnode.child[1]
else:
val = cnode.calc_value(env)[0]
if type(val) == list:
val = args_restore(val)
if not val:
res = val
if not self.static:
self.value = res
return res