RegExp

Regular expression compilation and matching. The Floe RegExp type is the runtime RegExp — passing it to TS APIs that take RegExp is zero-cost.

Functions

Function	Signature	Description
RegExp.compile	(string, string) -> Result<RegExp, ParseError>	Compile pattern + flags. Returns Err on invalid syntax.
RegExp.test	(RegExp, string) -> bool	Whether the pattern matches the string
RegExp.exec	(RegExp, string) -> Option<Array<string>>	First match’s full text + capture groups, or None
RegExp.source	(RegExp) -> string	The original pattern string
RegExp.flags	(RegExp) -> string	The flags string (e.g. "i", "gm")

Examples

match RegExp.compile("^[a-z]+", "i") {
    Ok(r) -> {
        let isWord = r |> RegExp.test("Hello")        // true
        let captures = r |> RegExp.exec("Hello world")
        // captures: Some(["Hello"])
    },
    Err(e) -> Console.error(e.message),
}

The flags argument is required — pass "" when you don’t need any. Common flags:

Flag	Meaning
"i"	Case-insensitive
"g"	Global (find all matches)
"m"	Multiline (^ / $ match line boundaries)
"s"	Dot matches newline
"u"	Unicode

RegExp.exec returns the first match plus its captured groups: Some(["fullMatch", "cap1", "cap2", ...]), or None if the pattern didn’t match. The name mirrors the underlying RegExp.prototype.exec JS API. With the "g" flag the underlying regex object advances lastIndex between calls, so re-using a global regex across calls walks through matches one at a time — bind to a fresh regex each time if that’s not what you want.