explain: Visualize Regular Expressions

Description

Visualize regular expressions using http://www.regexper.com & http://rick.measham.id.au/paste/explain.

Usage

explain(pattern, open = FALSE, dictionary = getOption("regex.library"))

Arguments

pattern

A character string containing a regular expression or a character string starting with "@" that is a regular expression from a qdapRegex dictionary.

open

logical. If TRUE the default browser will attempt to open http://www.regexper.com page. Setting open = 2 will utilize an unstable visualization via https://www.debuggex.com. This approach utilizes a no

dictionary

A dictionary of canned regular expressions to search within.

Value

Prints http://rick.measham.id.au/paste/explain to the console, attempts to open the url to the visual representation provided by http://www.regexper.com, and invisibly returns a list with the URLs.

Details

Note that http://www.regexper.com is a Java based regular expression viewer. Lookbehind and negative lookbehinds are not respected.

References

http://stackoverflow.com/a/27489977/1000343 http://www.regexper.com http://rick.measham.id.au/paste/explain http://stackoverflow.com/a/27574103/1000343

Examples

Run this code

explain("\\s*foo[A-Z]\\d{2,3}")
explain("@rm_time")
explain("\\s*foo[A-Z]\\d{2,3}", open = TRUE)
explain("@rm_time", open = TRUE)

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