R regex：grep不包括连字符/破折号作为边界

I am trying to match an exact word in in a vector with variable strings. For this I am using boundaries. However, I would like for hyphen/dash not to be considered as word boundary. Here is an example:

我试图在一个带有变量字符串的向量中匹配一个确切的单词。为此,我使用边界。但是,我想将连字符/短划线视为字边界。这是一个例子:

vector<-c(    
"ARNT",
"ACF, ASP, ACF64",
"BID",
"KTN1, KTN",
"NCRNA00181, A1BGAS, A1BG-AS",
"KTN1-AS1")

To match strings that contain "KTN1" I am using:

要匹配包含“KTN1”的字符串我正在使用:

grep("(?i)(?=.*\\bKTN1\\b)", vector, perl=T)

But this matches both "KTN1" and "KTN1-AS1".

但这与“KTN1”和“KTN1-AS1”相匹配。

Is there a way I could treat the dash as a character so that "KTN1-AS1" is considered a whole word?

有没有办法可以将短划线视为一个角色,以便“KTN1-AS1”被认为是一个完整的单词?

2 个解决方案

#1

To match a particular word from an vector element, you need to use functions like regmatches , str_extract_all (from stringr package) not grep, since grep would return only the element index where the match is found.

要匹配vector元素中的特定单词,需要使用regmatches,str_extract_all(来自stringr包)等函数而不是grep,因为grep只返回找到匹配项的元素索引。

> vector<-c(    
+     "ARNT",
+     "ACF, ASP, ACF64",
+     "BID",
+     "KTN1, KTN",
+     "NCRNA00181, A1BGAS, A1BG-AS",
+     "KTN1-AS1")
> regmatches(vector, regexpr("(?i)\\bKTN1[-\\w]*\\b", vector, perl=T))
[1] "KTN1"     "KTN1-AS1"

> library(stringr)
> unlist(str_extract_all(vector[grep("(?i)\\bKTN1[-\\w]*\\b", vector)], perl("(?i).*\\bKTN1[-\\w]*\\b")))
[1] "KTN1"     "KTN1-AS1"

Update:

> grep("\\bKTN1(?=$|,)", vector, perl=T, value=T)
[1] "KTN1, KTN"

Returns the element which contain the string KTN1 followed by a comma or end of the line.

返回包含字符串KTN1后跟逗号或行尾的元素。

> grep("\\bKTN1\\b(?!-)", vector, perl=T, value=T)
[1] "KTN1, KTN"

Returns the element which contain the string KTN1 not followed by a hyphen.

返回包含字符串KTN1后面没有连字符的元素。

#2

I would keep this simple and create a DIY Boundary.

我会保持这个简单并创建一个DIY边界。

grep('(^|[^-\\w])KTN1([^-\\w]|$)', vector, ignore.case = TRUE)

We use a capture group to define the boundaries. We match a character that is not a hyphen or a word character — beginning or end of string, which is closer to the intent of the \b boundary .

我们使用捕获组来定义边界。我们匹配一个不是连字符或单词字符的字符 - 字符串的开头或结尾,它更接近\ b边界的意图。

#1