[英]Can I improve this GOLD Parser Grammar?
I have to parse a file that looks like this: 我必须解析一个看起来像这样的文件:
versioninfo
{
"editorversion" "400"
"editorbuild" "4715"
}
visgroups
{
}
world
{
"id" "1"
"mapversion" "525"
"classname" "worldspawn"
solid
{
"id" "2"
side
{
"id" "1"
"plane" "(-544 -400 0) (-544 -240 0) (-272 -240 0)"
}
side
{
"id" "2"
"plane" "(-544 -240 -16) (-544 -400 -16) (-272 -400 -16)"
}
}
}
I have a parser written from scratch, but it has a few bugs that I can't track down and I imagine it'll be difficult to maintain if the format changes in the future. 我有一个从头开始编写的解析器,但它有一些我无法追踪的错误,我想如果格式在将来发生变化,将难以维护。 I decided to use the GOLD Parsing System to generate a parser, instead.
我决定使用GOLD Parsing System来生成解析器。 My grammar looks like this:
我的语法看起来像这样:
"Start Symbol" = <SectionList>
! SETS
{Section Chars} = {AlphaNumeric} + [_]
{Property Chars} = {Printable} - ["]
! TERMINALS
SectionName = {Section Chars}+
PropertyPart = '"' {Property Chars}* '"'
! RULES
<SectionList> ::= <Section>
| <Section> <SectionList>
<SectionBody> ::= <PropertyList>
| <SectionList>
| <PropertyList> <SectionList>
<Section> ::= SectionName '{' '}'
| SectionName '{' <SectionBody> '}'
<PropertyList> ::= <Property>
| <Property> <PropertyList>
<Property> ::= PropertyPart PropertyPart
There are no errors and it parses my 2000-line test file just fine. 没有错误,它解析我的2000行测试文件就好了。 However, this is my first time writing a custom grammar, so I'm not sure if I'm doing it correctly.
但是,这是我第一次编写自定义语法,所以我不确定我是否正确使用它。
Are there any improvements I could make to the grammar above? 我可以对上面的语法做出哪些改进?
below are some changes i would request to change for better performance 以下是我要求更改以获得更好性能的一些更改
1) make the grammar left recursive rules. 1)使语法保持递归规则。 this is better in terms of making shift reduce operations as gold parser is a shift reduce LR parser.
这在制作移位减少操作方面更好,因为黄金解析器是一个移位减少LR解析器。
SectionList ::= Section SectionList :: = Section
| SectionList Section
PropertyList ::= Property PropertyList :: = Property
| PropertyList Property
2) third rule in below section forces you to have propertylist only before sectionlist but not between different 's. 2)以下部分中的第三条规则强制您仅在分区列表之前具有属性列表,而不是在区分列表之间。 make sure its as per requirement
根据要求确定它
SectionBody ::= PropertyList SectionBody :: = PropertyList
| SectionList
| PropertyList SectionList
i can help you better if required and if you let me know the language saying " it should accept this , shouldn't accept this" rather than a sample input which will not give 100% picture of your language. 如果需要,我可以帮助你更好,如果你让我知道“它应该接受这个,不应该接受这个”的语言,而不是一个不能100%描述你的语言的样本输入。 or let me know the bugs you felt from which we can define the language description also.
或者让我知道您认为我们可以定义语言描述的错误。
Regards, VM Rakesh (rakesh.vm@gmail.com) 此致,VM Rakesh(rakesh.vm@gmail.com)
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