def prepare_symbols_and_productions():
f = open('grammer.txt', 'r')
lines = f.readlines()
terminal = False
production = False
for l in lines:
if l.strip() == '*terminals':
terminal = True
production = False
continue
if l.strip() == '*productions':
terminal = False
production = True
continue
if l.strip() == '*end':
break
if terminal:
TERMINAL_SET.update([l.strip()])
if production:
left = l.split('::=')[0].strip()
NON_TERMINAL_SET.update([left])
try:
right = l.split('::=')[1].strip()
if right == '':
raise IndexError
p = Production(left, right.split(' '))
except IndexError:
p = Production(left, ['null'])
PRODUCTION_LIST.append(p)
for s in TERMINAL_SET:
sym = Symbol(s, sym_type='T')
SYMBOL_DICT[s] = sym
for s in NON_TERMINAL_SET:
sym = Symbol(s, sym_type='N')
SYMBOL_DICT[s] = sym
def prepare_symbols_and_productions():
f = open("grammer.txt", "r")
lines = f.readlines()
terminal = False
production = False
for l in lines:
if l.strip() == "*terminals":
terminal = True
production = False
continue
if l.strip() == "*productions":
terminal = False
production = True
continue
if l.strip() == "*end":
break
if terminal:
TERMINAL_SET.update([l.strip()])
if production:
left = l.split("::=")[0].strip()
NON_TERMINAL_SET.update([left])
try:
right = l.split("::=")[1].strip()
if right == "":
raise IndexError
p = Production(left, right.split(" "))
except IndexError:
p = Production(left, ["null"])
PRODUCTION_LIST.append(p)
for s in TERMINAL_SET:
sym = Symbol(s, sym_type="T")
SYMBOL_DICT[s] = sym
for s in NON_TERMINAL_SET:
sym = Symbol(s, sym_type="N")
SYMBOL_DICT[s] = sym
def atom(token):
if token == '#t':
return True
if token == '#f':
return False
if token.startswith('#\\'):
return Char(token) # TODO (RCZ) - Should I cut off the #\ ?
try:
return ast.literal_eval(token)
except ValueError:
pass
except SyntaxError:
pass
return Symbol(token)