def R(parent, table): #<条件语句>
child = Node('<条件语句>')
parent.add(child)
if SYM[p] == KEYWORDS['if']:
child.add(Node('if'))
advance()
K(child, table)
ret = Code('JPC', 0, None)
code.append(ret)
if SYM[p] != KEYWORDS['then']:
child.add(Node('then'))
H(child, table)
ret.a = len(code)
print(Position[p], "缺少then")
global Error
Error = 1
else:
child.add(Node('then'))
advance()
H(child, table)
ret.a = len(code)
# while :
else:
print(Position[p], "递归错误")
Error = 1
def R(parent, table): #<条件语句>
child = Node('<条件语句>')
parent.add(child)
if SYM[p] == KEYWORDS['if']:
child.add(Node('if'))
advance()
K(child, table)
ret = Code('JPC', 0, None)
code.append(ret)
if SYM[p] == KEYWORDS['then']:
child.add(Node('then'))
advance()
H(child, table)
ret.a = len(code)
else:
error()
else:
error()
def T(parent, table): #<当型循环语句>
child = Node('<当型循环语句>')
parent.add(child)
if SYM[p] == KEYWORDS['while']:
child.add(Node('while'))
advance()
ret = len(code)
K(child, table)
fret = Code('JPC', 0, None)
code.append(fret)
if SYM[p] == KEYWORDS['do']:
child.add(Node('do'))
advance()
H(child, table)
code.append(Code('JMP', 0, ret))
fret.a = len(code)
else:
error()
else:
error()
def T(parent, table): #<当型循环语句>
child = Node('<当型循环语句>')
parent.add(child)
if SYM[p] == KEYWORDS['while']:
child.add(Node('while'))
advance()
ret = len(code)
K(child, table)
fret = Code('JPC', 0, None)
code.append(fret)
if SYM[p] == KEYWORDS['do']:
child.add(Node('do'))
advance()
H(child, table)
code.append(Code('JMP', 0, ret))
fret.a = len(code)
else:
print(Position[p], "while后面缺少do")
global Error
Error = 1
else:
print(Position[p], "递归错误")
error()