R: Replace matched substrings with new text

ore.subst {ore}

R Documentation

Replace matched substrings with new text

Description

This function substitutes new text into strings in regions that match a regular expression. The substitutions may be simple text, may include references to matched subgroups, or may be created by an R function.

Usage

ore.subst(regex, replacement, text, ..., all = FALSE)

Arguments

`regex`	A single character string or object of class `"ore"`. In the former case, this will first be passed through `ore`.
`replacement`	A single character string, or a function to be applied to the matches.
`text`	A vector of strings to match against.
`...`	Further arguments to `replacement`, if it is a function.
`all`	If `TRUE`, then all matches within each element of `text` will be found. Otherwise, the search will stop at the first match.

Details

If replacement is a function, then it will be passed as its first argument an object of class "orearg". This is a character vector containing as its elements the matched substrings, and with an attribute containing the matches for parenthesised subgroups, if there are any. A groups method is available for this class, so the groups attribute can be easily obtained that way. The substitution function will be called once per element of text.

Value

A version of text with the substitutions made.

Examples

# Simple text substitution (produces "no dogs")
ore.subst("\\d+", "no", "2 dogs")

# Back-referenced substitution (produces "22 dogs")
ore.subst("(\\d+)", "\\1\\1", "2 dogs")

# Function-based substitution (produces "4 dogs")
ore.subst("\\d+", function(i) as.numeric(i)^2, "2 dogs")

[Package ore version 1.6.0 Index]