Standard Library: Re

Use regular expressions to search and manipulate strings

As Pointless is currently implemented in JavaScript, it inherits some of the limitations of the UTF-16 encoding that JS uses, for example: 

Re.test("☺", "^.$") -- '.' matches BMP character U+263A
Re.test("😀", "^.$") -- '.' doesn't match SMP character U+1F600
true
false
  1. escape
  2. match
  3. replace
  4. replaceBy
  5. split
  6. test

Re.escape(string)

Escape special characters in string so it can be used as a literal in a regular expression. 

Re.escape("Hello? Can you *hear* me??")
"Hello\\? Can you \\*hear\\* me\\?\\?"

Re.match(string, pattern)

Find the matches for pattern in string.

Return a table with the following columns:

  • value: The matched substring.
  • index: Index of value in string.
  • groups: List of captures.
  • named: Object of named captures.
Re.match("nessa@example.com, megan@xkcd.com", r"(?<name>\w+)@(\w+\.\w+)")
┌───────────────────┬───────┬──────────────────────────┬───────────────────┐
│ value             │ index │ groups                   │ named             │ x 2
├───────────────────┼───────┼──────────────────────────┼───────────────────┤
│ nessa@example.com │     0 │ ["nessa", "example.com"] │ { name: "nessa" } │
│ megan@xkcd.com    │    19 │ ["megan", "xkcd.com"]    │ { name: "megan" } │
└───────────────────┴───────┴──────────────────────────┴───────────────────┘

Re.replace(string, pattern, replacement)

Replace all matches of pattern in string with replacement. 

Re.replace("2025  07 22", " +", ".")
"2025.07.22"

Re.replaceBy(string, pattern, replacer)

Replace all matches of pattern in string with replacement. 

Re.replaceBy("a catalog of cats", r"cat\w*", Str.toUpper)
"a CATALOG of CATS"

Re.split(string, pattern)

Split string using the regular expression pattern. The matching separators are not included in the resulting substrings. 

Re.split("NYC NY  USA", " +")
["NYC", "NY", "USA"]

Re.test(string, pattern)

Check whether string matches the regular expression pattern. 

Re.test("nessa@example.com", r".+@.+\..+")
Re.test("nessa at example dot com", r".+@.+\..+")
true
false