This package contains number-related functionality for the rebus package. It is primarily intended for other R package developers. For interactive use, try rebus instead.

Regular expressions are a very powerful tool, but the syntax is terse enough to be difficult to read. This makes bugs easy to introduce and hard to find. This package contains functions to make building regular expressions easier.

To install the stable version, type:

install.packages("rebus.numbers")

To install the development version, you first need the devtools package.

install.packages("devtools")

Then you can install the rebus.numbers package using

library(devtools)
install_github("richierocks/rebus.numbers")

number_range creates a regex that matches a range of integers. For example, number_range(-12, 123) generates (?:-(?:[1-9]|1[0-2])|(?:0[0-9]{2}|1[0-1][0-9]|12[0-3])).

roman generates a regex to match roman numerals, and ROMAN provides the constant form. For example roman(2, 3) matches two or three roman numbers.