Course of Raku / Regexes and grammars / Regexes / Literals and character classes / Exercises / A letter or digit

Solution: A letter or digit

Here is a possible solution to the task.

Code

say '  @x7' ~~ / <[a..z 0..9]> /;

🦋 You can find the source code in the file digit-class.raku.

Output

｢x｣

Comments

  1. A class can hold several ranges, one after another. <[a..z 0..9]> matches one character that is a lowercase letter or a digit. The space between the two ranges is only there for readability — <[a..z0..9]> means exactly the same, because spaces inside <[…]> are ignored, just as they are elsewhere in a regex.

  2. Scanning from the left, the two spaces and the @ are not in the class and are skipped; the first matching character is x. (This combined class is close to what the shortcut \w stands for.)

Course navigation

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