syntax-error - 结合断言子句和where子句

Question

我注意到，当我有多个where子句和多个asserting子句时，将它们组合在一起经常会出现语法错误。该错误将显示“where之后出现意外 token ”。我应该如何编写以避免发生此错误？这是最新的示例:

尝试1:

def(class game_state game) ->commands [
        set(attack, cost),
        set(life, cost),
        set(abilities, []),
    ] where cost=(card.cost + (card.loyalty_cost * size(card.school)))
      where card=crypt_spells[choices[0]]
//      asserting size(choices) = 1 //FIXME: syntax error uncommented
        asserting choices != null
      where crypt_spells=filter(game.crypt.cards_of(player), value.type='spell')
      where player=game.player_obj

我还尝试以另一种方式重写它，这也导致了“where where之后的意外标记”语法错误。

尝试2:

def(class game_state game) ->commands [
        set(attack, cost),
        set(life, cost),
        set(abilities, []),
    ] where cost=(card.cost + (card.loyalty_cost * size(card.school)))
      where card=crypt_spells[choices[0]]
      asserting choices != null, size(choices)=1 | choices //FIXME: syntax error
      where crypt_spells=filter(game.crypt.cards_of(player), value.type='spell')
      where player=game.player_obj

示例3:

我认为这是另一个突出问题的示例:

def(class game_state game, class message.play_card info) ->commands
  if(info.choices,
    ([ /* do stuff */ ]
      where entry=game.crypt.get_entry(info.choices[0])
      asserting size(info.targets)=1 | info.targets    /* PARSE ERROR! */
    ) asserting size(info.choices)=1 | info.choices,   /* WORKS */
    [ /* else */ ]
  )

从此示例中可以看到，除非在 asserting a=b子句之前加了 where，否则它可以正常工作。

Answer 1

让我尝试将您的代码转换为通用的调试控制台代码:

f()
where f = def
        () -> commands [
                debug(['something']),
                debug(['more stuff']),
                debug(['yet more stuff']),
        ]
        where aaa = (0 + (1 * 2))
        where bbb = 4
//        asserting 2 + 2 = 4 // FIXME: syntax error uncommented
        asserting '000' != null
        where ccc = [0, 1, 2, 3]
        where ddd = {'0': 0, '1': 1, }

调试控制台可以执行以下操作:

(debug console):0: ['something']
(debug console):0: ['more stuff']
(debug console):0: ['yet more stuff']
[(Command Object: N10game_logic12_GLOBAL__N_113debug_commandE),
 (Command Object: N10game_logic12_GLOBAL__N_113debug_commandE),
 (Command Object: N10game_logic12_GLOBAL__N_113debug_commandE)]

取消注释断言时，让我们检查您的语法错误是否仍然存在，或至少存在一些语法错误:

f()
where f = def
        () -> commands [
                debug(['something']),
                debug(['more stuff']),
                debug(['yet more stuff']),
        ]
        where aaa = (0 + (1 * 2))
        where bbb = 4
        asserting 2 + 2 = 4 // FIXME: syntax error uncommented
        asserting '000' != null
        where ccc = [0, 1, 2, 3]
        where ddd = {'0': 0, '1': 1, }

调试控制台无法执行:

error parsing formula: formula.cpp:3942 ASSERTION FAILED: Unexpected tokens after
where
At (debug console) 0:
... where bbb = 4       asserting 2 + 2 = 4 // FIXME syntax error uncommen...
                                        ^

该引擎使用简单的解析，目前 where， asserting和 =(甚至 ,吗？)可以通过直观的方式进行组合，但解析器无法很好地管理。

在这里，我认为它在到达 =之前找到了 where的辅助 ,，但我不知道。现在，我不确切知道完成 where解析的标准是什么。您将通过调试解析器来知道。

这是一个重要的问题，但可能并不关键，必须立即解决，因为大多数情况下可以通过包括更多的详细说明来解决。

让我们只放置一对parens，让我们从失败的断言开始:

f()
where f = def
        () -> commands [
                debug(['something']),
                debug(['more stuff']),
                debug(['yet more stuff']),
        ]
        where aaa = (0 + (1 * 2))
        where bbb = 4
        asserting (2 + 2 = 4) // FIXME: syntax error uncommented
        asserting '000' != null
        where ccc = [0, 1, 2, 3]
        where ddd = {'0': 0, '1': 1, }

调试控制台可以再次执行:

(debug console):0: ['something']
(debug console):0: ['more stuff']
(debug console):0: ['yet more stuff']
[(Command Object: N10game_logic12_GLOBAL__N_113debug_commandE),
 (Command Object: N10game_logic12_GLOBAL__N_113debug_commandE),
 (Command Object: N10game_logic12_GLOBAL__N_113debug_commandE)]

2018年5月27日添加了错误定位点。