Javascript 这个语法怎么会模棱两可？

我正在用Jison编写一个简单的表达式解析器。这是我的语法：

{
    "operators": [
        ["left", "+", "-"],
        ["left", "*", "/", "%"]
    ],
    "bnf": {
        "program": [
            ["statement EOF", "return $1;"]
        ],
        "statement": [
            ["expression NEWLINE", "$$ = $1 + ';';"]
        ],
        "expression": [
            ["NUMBER",                       "$$ = yytext;"],
            ["expression binary expression", "$$ = $1 + $2 + $3;"]
        ],
        "binary": [
            ["+",              "$$ = ' + ';"],
            ["-",              "$$ = ' - ';"],
            ["*",              "$$ = ' * ';"],
            ["/",              "$$ = ' / ';"],
            ["%",              "$$ = ' % ';"],
            ["binary NEWLINE", "$$ = $1;"]
        ]
    }
}

当我尝试运行它时，会出现以下错误：

Conflict in grammar: multiple actions possible when lookahead token is + in state
13
- reduce by rule: expression -> expression binary expression
- shift token (then go to state 8)
Conflict in grammar: multiple actions possible when lookahead token is - in state
13
- reduce by rule: expression -> expression binary expression
- shift token (then go to state 9)
Conflict in grammar: multiple actions possible when lookahead token is * in state
13
- reduce by rule: expression -> expression binary expression
- shift token (then go to state 10)
Conflict in grammar: multiple actions possible when lookahead token is / in state
13
- reduce by rule: expression -> expression binary expression
- shift token (then go to state 11)
Conflict in grammar: multiple actions possible when lookahead token is % in state
13
- reduce by rule: expression -> expression binary expression
- shift token (then go to state 12)

States with conflicts:
State 13
  expression -> expression binary expression . #lookaheads= NEWLINE + - * / %
  expression -> expression .binary expression
  binary -> .+
  binary -> .-
  binary -> .*
  binary -> ./
  binary -> .%
  binary -> .binary NEWLINE

然而，它最终仍然会产生正确的输出。例如，将

2+3*5/7%11

正确翻译为

2+3*5/7%11

在我看来，我的语法似乎很明确，那么吉森为什么要抱怨呢

更新：正如@icktoofay解释的，这是一个运算符关联性问题。通过将运算符解析为非终端符号，运算符的优先级和关联性信息将丢失。因此，我解决了以下问题：

{
    "operators": [
        ["left", "+", "-"],
        ["left", "*", "/", "%"]
    ],
    "bnf": {
        "program": [
            ["statement EOF", "return $1;"]
        ],
        "statement": [
            ["expression NEWLINE", "$$ = $1 + ';';"]
        ],
        "expression": [
            ["NUMBER",                          "$$ = yytext;"],
            ["expression + expression",         "$$ = $1 + ' + ' + $3;"],
            ["expression - expression",         "$$ = $1 + ' - ' + $3;"],
            ["expression * expression",         "$$ = $1 + ' * ' + $3;"],
            ["expression / expression",         "$$ = $1 + ' / ' + $3;"],
            ["expression % expression",         "$$ = $1 + ' % ' + $3;"],
            ["expression + NEWLINE expression", "$$ = $1 + ' + ' + $4;"],
            ["expression - NEWLINE expression", "$$ = $1 + ' - ' + $4;"],
            ["expression * NEWLINE expression", "$$ = $1 + ' * ' + $4;"],
            ["expression / NEWLINE expression", "$$ = $1 + ' / ' + $4;"],
            ["expression % NEWLINE expression", "$$ = $1 + ' % ' + $4;"]
        ]
    }
}

也就是说，这种语法只允许一个可选换行符跟在二进制运算符后面。如何重写它，以允许任意数量的换行符跟随二进制运算符？另外，必须有某种方式，我不必为每个运算符编写两条规则。
我对Jison不太熟悉，但看起来您正在定义一条如下所示的规则：

expression ::= number;
expression ::= expression binary expression;

考虑表达式
1-2-3
。这可以解释为
（1-2）-3
或
1-（2-3）
。是哪一个？你的语法模棱两可。正常的数学规则说它应该是左关联的。你需要让你的语法反映出：

expression ::= number;
expression ::= expression binary number;

你说得对。运算符关联性确实是个问题。非常感谢。我可以麻烦你做点别的事吗？我已经编辑了我的问题，我想知道你对此的看法。也许我应该把它作为一个单独的问题发布？@AaditMShah：我只是修改lexer来合并连续的换行符。至于有
新行
/无
新行
需要两个产品，也许你可以用两个产品制作一个新的
新行
，一个为空，一个为
新行
。（事实上，如果你不想修改lexer，你可以有一个
maybe\u newline
和一个
maybe\u newline
production。）