Pattern Matching for Letters considering Blanks

Match pattern of letters considering blanks within each element of a character vector, allowing counted characters between and around each letter. Used as an auxiliary function for the Scrabble family of functions.

Usage

grepl_letters(x, pattern, blank = "_")

Arguments

x

Character vector

pattern

Character. Character string containing a semi-regular expression which uses the following logic: "a_b" means any character that contains "a" followed by something followed by "b", anywhere in the string.

blank

Character. String to use between letters.

Value

Boolean check for each value on x.

Examples

x <- c("aaaa", "bbbb", "baba", "aabb", "a", "ab")
grepl_letters(x, "ab")
#> [1] FALSE FALSE  TRUE  TRUE FALSE  TRUE
grepl_letters(x, "_ab")
#> [1] FALSE FALSE  TRUE  TRUE FALSE FALSE
grepl_letters(x, "a_a")
#> [1]  TRUE FALSE  TRUE FALSE FALSE FALSE
grepl_letters(x, "c")
#> [1] FALSE FALSE FALSE FALSE FALSE FALSE