我已经有函数提供滞后到一行。我的问题是，我需要找到下一个示例（之前或之后），其中strdetect=TRUE如果它不在紧接的之前或之后。（例如：TRUE发生在第三行而不是第一行）。我正在使用以下软件包

library(tidytext)
library(dplyr)
library(stringr)

这是我用来查看一行后面的函数：

#function to look behind one (
r_sen_from_states_alabama <- function(x){
  ifelse(str_detect(x, regex("the senator from Alabama",ignore_case = TRUE))==TRUE & str_detect(lag(x),"^Mr\\. SHELBY \\(R; Alabama\\):")==TRUE,
         str_replace(x,regex("the senator from Alabama", ignore_case = TRUE),"senator Shelby"),
         ifelse(str_detect(x, regex("the senator from Alabama", ignore_case = TRUE))==TRUE & str_detect(lag(x),"^Mr\\. SESSIONS \\(R; Alabama\\):")==TRUE,
                str_replace(x, regex("the senator from Alabama",ignore_case = TRUE), "senator Sessions"),x))
}

这是我用来向前看一行的函数：

#function to look ahead one
r_sen_from_states_alabama <- function(x){
  ifelse(str_detect(x, regex("the senator from Alabama",ignore_case = TRUE))==TRUE & str_detect(lead(x),"^Mr\\. SHELBY \\(R; Alabama\\):")==TRUE,
         str_replace(x,regex("the senator from Alabama", ignore_case = TRUE),"senator Shelby"),
         ifelse(str_detect(x, regex("the senator from Alabama", ignore_case = TRUE))==TRUE & str_detect(lead(x),"^Mr\\. SESSIONS \\(R; Alabama\\):")==TRUE,
                str_replace(x, regex("the senator from Alabama",ignore_case = TRUE), "senator Sessions"),x))
}
test_df_try_1 <- as.data.frame(r_sen_from_states_alabama(test_df))

下面是一些用于复制/调试目的的示例数据。

#testing env data
test_col <- c("Mr. SHELBY (R; Alabama): I acknowledge this is a test.",
              "Mrs. MURRAY (D; Washington): I say to my friend, the senator from Alabama, that they are wrong.",
              "Mr. SHELBY (R; Alabama): I do not agree with my colleague.",
              "Mr. FRIST (R; Tennessee): The senator from Alabama is correct, senator Murray.",
              "Mr. SHELBY (R; Alabama): I thank the majority leader for their support.",
              "Mr. SESSIONS (R; Alabama): I am proud of my junior, the senator from Alabama.",
              "Mr. SHELBY (R; Alabama): To my senior peer, the senator from Alabama, I say great things.",
              "Ms. PEABODY (I; Atlantis): This is just to fill space.",
              "Mr. Quail (Q; Nowhere): Match this one, the senator from Alabama, with the senator at the bottom.",
              "Ms. PEABODY (I; Atlantis): This is just to fill space.",
              "Ms. PEABODY (I; Atlantis): This is just to fill space!",
              "Ms. PEABODY (I; Atlantis): This is just to fill space?",
              "Mr. SESSIONS (R; Alabama): Match this one with Quail.")

test_df <- data.frame(test_col)
colnames(test_df) <- c("speeches")

已编辑以包括预期输出：

#Desired hypothetical results when using lag [note: 9 went lag(n = 2)
1   Mr. SHELBY (R; Alabama): I acknowledge this is a test.
2   Mrs. MURRAY (D; Washington): I say to my friend, senator Shelby, that they are wrong.
3   Mr. SHELBY (R; Alabama): I do not agree with my colleague.
4   Mr. FRIST (R; Tennessee): senator Shelby is correct, senator Murray.
5   Mr. SHELBY (R; Alabama): I thank the majority leader for their support.
6   Mr. SESSIONS (R; Alabama): I am proud of my junior, senator Shelby.
7   Mr. SHELBY (R; Alabama): To my senior peer, senator Sessions, I say great things.
8   Ms. PEABODY (I; Atlantis): This is just to fill space.
9   Mr. Quail (Q; Nowhere): Match this one, senator Shelby, with the senator before.
10  Ms. PEABODY (I; Atlantis): This is just to fill space.
11  Ms. PEABODY (I; Atlantis): This is just to fill space!
12  Ms. PEABODY (I; Atlantis): This is just to fill space?
13  Mr. SESSIONS (R; Alabama): Match this one with Quail.

#Desired hypothetical results when using lead [note: 6 went lead(n=7, 9 went lead(n=4)]
1  Mr. SHELBY (R; Alabama): I acknowledge this is a test.
2  Mrs. MURRAY (D; Washington): I say to my friend, senator Shelby, that they are wrong.
3  Mr. SHELBY (R; Alabama): I do not agree with my colleague.
4  Mr. FRIST (R; Tennessee): senator Shelby is correct, senator Murray.
5  Mr. SHELBY (R; Alabama): I thank the majority leader for their support.
6  Mr. SESSIONS (R; Alabama): I am proud of my junior, senator Shelby.
7  Mr. SHELBY (R; Alabama): To my senior peer, senator Sessions, I say great things.
8  Ms. PEABODY (I; Atlantis): This is just to fill space.
9  Mr. Quail (Q; Nowhere): Match this one, senator Sessions, with the senator at the bottom.
10 Ms. PEABODY (I; Atlantis): This is just to fill space.
11 Ms. PEABODY (I; Atlantis): This is just to fill space!
12 Ms. PEABODY (I; Atlantis): This is just to fill space?
13 Mr. SESSIONS (R; Alabama): Match this one with Quail.