Dots

You can use the dot (.) to match any character, except line breaks. For example:

...  # 3 characters

Most regex engines have a “singleline” option that changes the behavior of .. When enabled, . matches everything, even line breaks. You could use this to check if a text fits in an SMS:

.{1,160}  # enforces the 160 character limit

If you want to match any character, without having to enable the “singleline” option, Pomsky also offers the variable C, or Codepoint:

Codepoint{1,160}

What’s a codepoint? #

I lied when I said that the dot matches a character; it actually matches a Unicode codepoint.

A Unicode codepoint usually, but not always, represents a character. Exceptions are composite characters like ć (which may consist of a ´ and a c when it isn’t normalized). Composite characters are common in many scripts, including Japanese, Indian and Arabic scripts. Also, an emoji can consist of multiple codepoints, e.g. when it has a gender or skin tone modifier.

Repeating the dot #

Be careful when repeating C or .. My personal recommendation is to never repeat them. Let’s see why:

'{' .* '}'

This matches any content surrounded by curly braces. Why is this bad? Because .* will greedily consume anything, even curly braces, so looking for matches in the string {ab} de {fg} will return the whole string, but we probably expected to get the two matches {ab} and {fg}.

We’ll see how this can be fixed in a bit.