我必须编写一个解析器来解析文件中的键值对,如下所示:
as235 242kj25klj 对:A=a1|B=b1|C=c1
kjlkjlkjlkj 对:A=a2|B=b2|C=c2
请注意,这些行包含一些垃圾、标签和键值对。
我编写的 F# 代码如下:
#r"FParsec.dll"
open FParsec
let parse keys label =
let pkey = keys |> Seq.map pstring |> choice
let pvalue = manyCharsTill anyChar (anyOf "|\n")
let ppair = pkey .>> (skipChar '=') .>>. pvalue
let ppairSeq = many ppair
let pline = skipManyTill anyChar (pstring label)
>>. ppairSeq .>> newline
let pfile = many (opt pline) |>> Seq.choose id
run pfile
>> function
| Success (result, _, _) -> result
| Failure (errorMsg, _, _) -> failwith errorMsg
"""
as235 242kj25klj Pairs:A=a1|B=b1|C=c1
lkjlkjlkjlkj Pairs:A=a2|B=b2|C=c2
"""
|> parse ["A";"B";"C"] "Pairs:"
|> List.ofSeq
|> printfn "%A"
预期结果是:
[[("A","a1"); "B","b1"; "C","c1"]
[("A","a2"); "B","b2"; "C","c2"]]
...但是我收到以下错误:
System.Exception: Error: Error in Ln: 8 Col: 1
Note: The error occurred at the end of the input stream.
Expecting: any char or 'Pairs:'
关于如何修复此解析器的任何想法?
谢谢!
更新:在斯蒂芬发表评论后,我试图修复它但没有成功。这是我希望工作的最后一次尝试,但事实并非如此。
let pkey = keys |> Seq.map pstring |> choice
let pvalue = manyCharsTill anyChar (anyOf "|\n")
let ppair = pkey .>> (skipChar '=') .>>. pvalue
let ppairSeq = manyTill ppair newline
let pnonEmptyLine =
skipManyTill anyChar (pstring label)
>>. ppairSeq
|>> Some
let pemptyLine = spaces >>. newline >>% None
let pline = pemptyLine <|> pnonEmptyLine
let pfile = manyTill pline eof |>> Seq.choose id
现在错误消息是:
Error in Ln: 2 Col: 5
as235 242kj25klj Pairs:A=a1|B=b1|C=c1
^
Expecting: newline