New Literal Forms in Nu
Nu-0.2.0 contains support for two new literal types: regular expressions and characters.
Regular Expression Literals
The Nu parser now allows regular expressions to be specified with the following form:
/regex/options
Here "regex" is a regular expression and "options" is a string of lower-case alphabetic characters.
The available options correspond to the options available for the NuRegex class:
| i | case insensitive comparison |
| s | dot metacharacter also matches newlines |
| x | allow whitespaces and comments in pattern |
| l | lazy quantifiers become greedy and vice versa |
| m | caret and dollar anchors match at newlines |
For example, /^f(o+)$/i matches strings "fo", "FOO",
and "fooooOOOOO".
To include forward slashes in regular expressions, prefix each forward slash with a backslash.
Character Literals
Character literals are single characters or escape sequences enclosed in pairs of single quotes ('). The same escape sequences are supported for character literals and strings. Internally, a character literal is represented by an NSNumber with the appropriate unicode value. This is the same value and type that is returned by the NSString characterAtIndex: method.