import Foundation
let pattern = ##"""
(?(DEFINE) # Start of definitions
(?P<str_double_quotes>
(?<!\\) # Not escaped
" # Match a double quote
(?: # Non-capturing group
[^\\] # Match anything not a backslash
| # Or
\\. # Match a backslash and a single character (ie: an escaped character)
)*? # Repeat the non-capturing group zero or more times, ungreedy/lazy
" # Match the ending double quote
)
(?P<str_single_quotes>
(?<!\\) # Not escaped
' # Match a single quote
(?: # Non-capturing group
[^\\] # Match anything not a backslash
| # Or
\\. # Match a backslash and a single character (ie: an escaped character)
)*? # Repeat the non-capturing group zero or more times, ungreedy/lazy
' # Match the ending single quote
)
(?P<brackets>
\( # Match an opening bracket
(?: # A non capturing group
(?&str_double_quotes) # Recurse/use the str_double_quotes pattern
| # Or
(?&str_single_quotes) # Recurse/use the str_single_quotes pattern
| # Or
[^()] # Anything not a bracket
| # Or
(?&brackets) # Recurse the bracket pattern
)*
\)
)
) # End of definitions
# Let's start matching for real now:
_n? # Match _ or _n
\s* # Optional white spaces
(?P<results>(?&brackets)) # Recurse/use the brackets pattern and put it in the results group
"""##
let regex = try! NSRegularExpression(pattern: pattern, options: [.allowCommentsAndWhitespace, .dotMatchesLineSeparators])
let testString = #"""
_ ("foo") // want "foo"
_n("bar", "baz", 42); // want "bar", "baz", 42
_n(domain, "bux", var); // want domain, "bux", var
_( "one (optional)" ); // want "one (optional)"
apples === 0 ? _( "No apples" ) : _n("%1 apple", "%1 apples", apples) // could have on the same line two calls..
// misleading cases
_n("foo (")
_n("foo (\)", 'foo)', aa)
_n( Array(1, 2, 3), Array(")", '(') );
_n(function(foo){return foo*2;}); // Is this even valid?
_n (); // Empty
_ (
"Foo",
'Bar',
Array(
"wow",
"much",
'whitespaces'
),
multiline
); // PCRE is awesome
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let matches = regex.matches(in: testString, range: stringRange)
var result: [[String]] = []
for match in matches {
var groups: [String] = []
for rangeIndex in 1 ..< match.numberOfRanges {
let nsRange = match.range(at: rangeIndex)
guard !NSEqualRanges(nsRange, NSMakeRange(NSNotFound, 0)) else { continue }
let string = (testString as NSString).substring(with: nsRange)
groups.append(string)
}
if !groups.isEmpty {
result.append(groups)
}
}
print(result)
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Swift 5.2, please visit: https://developer.apple.com/documentation/foundation/nsregularexpression