Shiny DT :: datatable的布尔'regexp'是什么？

Question

There is an option in R Shiny that allows making a search by 'regexp'. Let say we have 2 strings to search: "Merc 230" and "Merc 280". The working "OR" regexp is "Merc 230 | Merc 280". What will be working regexp for AND and NOT operators?

library(DT)

DT::datatable(mtcars,  options = list(
    search = list(regex = TRUE)))

String in "Search" box of datatable:

1 - OR: Merc 230 | Merc 280 - work

2 - AND: Merc 230 & Merc 280 - not work

3 - NOT: ! Merc 230 & Merc 280 - not work

Thanks

Answer 1

Im no regex expert but I have the following examples for you. The work with str_detect() from the stringr package. I am not sure if the also work with DT::datatable but I would expect them to.

library(stringr)

dummy <- c("Merc 220 Merc 210", "Merc 230 xxx Merc 280", "Merc 220 xxx Merc 280")

pattern1 <- "Merc 230|Merc 280"
str_detect(dummy, pattern1)
pattern2 <- "Merc 230.*Merc 280"
str_detect(dummy, pattern2)
pattern3 <- "^(?!(.*Merc 230.*|.*Merc 280.*))"
str_detect(dummy, pattern3)

The pattern .* stands for zero or more characters of any kind. ^(?!.*...) means start of string not followed by zero or more characters of any kind and the expression you want to exclude.

To learn more about regular expressions I would recommend reading the Rstudio Cheatsheet on strings .