Mojo struct
CharacterClass
struct CharacterClass
Represents a character class in a regular expression.
Character classes represent sets of characters that can match at a position, such as digits, letters, or custom sets defined with brackets.
In regex syntax, character classes can be predefined (like \d for digits) or custom-defined using brackets (like [a-z] for lowercase letters). This struct provides a way to represent and work with these classes.
The struct stores both a name for the class (e.g., "digit" for \d) and the actual set of characters that belong to the class. It also provides methods to check if a given character is a member of the class.
Example usage:
var digit_class = CharacterClass("digit", "0123456789")
if digit_class.matches("5"):
print("5 is a digit")
var digit_class = CharacterClass("digit", "0123456789")
if digit_class.matches("5"):
print("5 is a digit")
Fields
- name (
String): The name of the character class. - chars (
String): The characters that are part of this class.
Implemented traits
AnyType,
Copyable,
ExplicitlyCopyable,
Movable,
UnknownDestructibility
Methods
__init__
__init__(out self, name: String, chars: String)
Initialize a character class.
Args:
- name (
String): The name of the character class (e.g., "digit", "word"). - chars (
String): The characters that are part of this class.
matches
matches(self, c: String) -> Bool
Check if a character is in this character class.
This method determines whether a given character is a member of this character class. It does this by checking if the character is present in the chars string for this class.
Note that this method expects a single character as input. If a string with multiple characters is provided, it will return False since character classes match exactly one character at a time.
The method uses the 'in' operator to check for membership, which for strings checks if one string is a substring of another. Since we're dealing with single characters, this effectively checks if the character is one of the allowed characters in the class.
Args:
- c (
String): The character to check for membership in this class. Should be a single character.
Returns:
True if the character is in this character class, False otherwise.
Raises:
If the string operation fails (unlikely with normal usage).
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