[英]Treetop ignores methods defined in grammar
I'm trying to parse a percentage with treetop. 我正在尝试使用树梢解析百分比。 I wrote the following grammar:
我写了以下语法:
grammar Numerals
rule percentage
(decimal "%") {
def to_f
decimal.to_f / 100
end
}
end
rule decimal
sign [0-9]+ '.' [0-9]* {
def to_f
text_value.to_f
end
}
end
rule sign
('+'/'-')?
end
end
This matches correctly, but for some reason the to_f
method on the root node is missing in the result. 这正确匹配,但是由于某种原因,结果中缺少根节点上的
to_f
方法。
When I checked the code generated by tt, it had created two modules for the percentage nodes, only one of which was used in the rest of the code: 当我检查tt生成的代码时,它为百分比节点创建了两个模块,其余代码仅使用其中一个:
module Percentage0
def decimal
elements[0]
end
end
module Percentage1
def to_f
decimal.to_f / 100
end
end
Percentage1 never appears anywhere else in the code, while Percentage0 is used on the correct nodes Percentage1永远不会出现在代码中的其他任何地方,而Percentage0用于正确的节点
r0 = instantiate_node(SyntaxNode,input, i0...index, s0)
r0.extend(Percentage0)
On the other hand, the to_f
method on decimal
works fine (also two modules, but both are used to extend the node). 另一方面,
decimal
的to_f
方法也可以正常工作(也有两个模块,但是都用于扩展节点)。 I can't find what is different about its definition, that causes this. 我找不到它的定义有什么不同,这导致了这一点。
I think you just need to remove the parentheses from the root rule. 我认为您只需要从根规则中删除括号即可。
Also, for the decimal rule you should probably use a +
instead of a *
after the decimal; 另外,对于十进制规则,您应该在小数点后使用
+
而不是*
; you'll want at least one number there. 您至少要有一个电话号码。
grammar Numerals
rule percentage
decimal "%" {
def to_f
decimal.to_f / 100
end
}
end
rule decimal
sign [0-9]+ '.' [0-9]+ {
def to_f
text_value.to_f
end
}
end
rule sign
('+'/'-')?
end
end
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