def analyze_logic_factor():
'''' !, logic_factor | logic_stmt '''
value = Parser.tok.curr
if not Parser.is_valid(value):
raise ValueError(f'invalid token {value.val} in logic factor')
if value.t == const.NOT:
return nd.UnOp(const.NOT, [Parser.analyze_logic_expr()])
else:
return Parser.analyze_logic_stmt()
def analyze_print():
value = Parser.tok.get_next() # should be open_par
if value.t != const.OPEN_PARENT:
raise ValueError('Unexpected token type {}, expected ('.format(
value.t))
result = nd.UnOp(const.PRINT, [Parser.analyze_expression()])
value = Parser.tok.curr
if value.t != const.CLOSE_PARENT:
raise ValueError('Unexpected token type {}, expected )'.format(
value.t))
Parser.tok.get_next()
return result
def analyze_fact():
''' analyze a factor, as defined in the README.md '''
value = Parser.tok.get_next()
if not Parser.is_valid(value):
raise ValueError(
'Invalid token at position {} of the string "{}"'.format(
Parser.tok.pos, Parser.tok.src))
if value.t == const.OPEN_PARENT:
# analyze expr
result = Parser.analyze_expression()
if Parser.tok.curr.val == const.CLOSE_PARENT:
return result
else:
raise ValueError(
'Expected closing parentesis, instead got {}'.format(
Parser.tok.curr.val))
elif value.t in const.SIGN_OPS:
# + or - factor
return nd.UnOp(value.t, [Parser.analyze_fact()])
elif value.t == const.INT:
return nd.IntVal(value.val, [])
elif value.t == const.VARIABLE:
if Parser.tok.peek().val == const.OPEN_PARENT:
return Parser.analyze_funccall()
return nd.VarVal(value.val, [])
elif value.t == const.RESERVED_WORD and value.val == const.SCANF:
value = Parser.tok.get_next()
if value.t != const.OPEN_PARENT:
raise ValueError(f'Unexpected token type {value.t}, ' +
'expected (')
value = Parser.tok.get_next()
if value.t != const.CLOSE_PARENT:
raise ValueError(f'Unexpected token type {value.t}, ' +
'expected )')
return nd.Scanf(value.val, [])
else:
utils.print_error(Parser)
raise ValueError(
'Unexpected token type, expected a factor, got a {}'.format(
value.t))
def p_out(p):
'out : PRINT relexp'
p[0] = nd.UnOp(p[1], [p[2]])
def p_factor_sign_num(p):
'''factor : PLUS expression %prec UPLUS
| MINUS expression %prec UMINUS
| NOT relexp'''
p[0] = nd.UnOp(p[1], [p[2]])
def analyze_return():
''' return <expression> '''
res = nd.UnOp(const.RETURN, [Parser.analyze_expression()])
return res