This R package provides 4 tiny regex tools to extract, match, and replace named regex groups in strings.It contains in addition to 3 functionsgroups(),match_group() andreplace_group() aR6 classReplacerwhich is thought as the main interface of this package.
You can install this package by installing it from CRAN or from this GitHub repository.
# install directly from CRANinstall.packages("regreplaceR")# or install directly from this github repository# install the devtools package if not already installedinstall.packages("devtools")# install the package directly from this repositorydevtools::install_github("gwangjinkim/regreplaceR")The package offers three core functions to interact with strings using regular expressions with named groups:
- groups(): Extract all named groups from a string.
- match_group(): Extract a specific named group.
- replace_group(): Replace the value of a specific named group.
Additionally, it includes an R6 class called Replacer that encapsulates these functionalities for a moreobject-oriented approach to regex-based operations.
I couldn't usematch() andreplace() as generic functions, because there are already generic functionswhich require a specific set of arguments.By using an R6 class, I was free to choose the arguments formatch() andreplace().
This function extracts all named groups from a string based on a provided regex pattern.
pattern<-"(?P<name>\\w+) is (?P<age>\\d+)"s<-"Jane is 25"result<- groups(pattern,s)# Output:# $name# [1] "Jane"## $age# [1] "25"
Extract the value of a specific named group from the string.
pattern<-"(?P<name>\\w+) is (?P<age>\\d+)"s<-"Jane is 25"name<- match_group(pattern,s,"name")# Output:# [1] "Jane"
Replace the value of a specific named group with a new string.
pattern<-"(?P<name>\\w+) is (?P<age>\\d+)"s<-"Jane is 25"modified<- replace_group(pattern,s,"name","John")# Output:# [1] "John is 25"
The Replacer class provides an object-oriented approach toregex-based operations. It allows you to create an instancewith a specific regex pattern and then use it to match or replacenamed groups in strings.
# Create a new Replacer objectr<-Replacer$new(pattern=".*?_(?P<date>\\d{8}-\\d{6})(?P<ext>\\..+$)")# Match a group within a stringdate<-r$match("file_20230905-123456.txt","date")# Replace the value of a matched groupmodified_string<-r$replace("file_20230905-123456.txt","date","20240905-123456")- match(): Extracts the value of a named group from the string.
- replace(): Replaces the value of a named group with a specified string.
This package is licensed under the MIT License. See LICENSE for details.
Happy regexing! If you have any questions or find any bugs, please feelfree to open an issue on the GitHub repository.