String arithmetic operators

Perform string concatenation and arithmetic in a similar way to other languages. String addition (%+%) glues strings together, string subtraction (%-%) removes a pattern, string multiplication (%s*%) repeats a string, and string division (%s/%) counts how many times a pattern occurs. String division has no equivalent in languages like 'Python', yet is arguably more useful than string multiplication, and it accepts regular expressions.

Usage

x %+% y

x %-% y

x %s*% y

x %s/% y

Arguments

x

a string (character vector)

y

a string (character vector or regular expression)

Value

A character vector for %+%, %-%, and %s*%, and an integer count for %s/%.

Author

Ben Wiseman, benjamin.h.wiseman@gmail.com

Examples

("ab" %+% "c") == "abc" # TRUE
#> [1] TRUE
("abc" %-% "b") == "ac" # TRUE
#> [1] TRUE
("ac" %s*% 2) == "acac" # TRUE
#>   ac 
#> TRUE 
("acac" %s/% "c") == 2  # TRUE
#>    c 
#> TRUE 
# String division with a regular expression:
"an apple a day keeps the malignant spirit of Steve Jobs at bay" %s/% "Steve Jobs|apple"
#> Steve Jobs|apple 
#>                2