import Foundation
// WARNING: You included a flag that Swift doesn't support: J
// Wehn this flag is set, it allows duplicated capturing group names.
// By default, Swift captures only the last value matched for a repeated capture group.
// As an alternative, the pattern can be modified to contain one capturing group per group you want to get in the result.
let pattern = #"""
(?<katex_all>
(?:
(?<!\\|\$)
(?<katex_open>
\${2}
|
\${1}
)
(?!\$)
\n?
(?<katex_content>.+?)\n?
(?<!\\|\$)
(?<katex_close>\g{katex_open})
(?!\$)
\n?
)
|
(?:
(?<!\\)
(?<katex_open>\\\[)
\n?
(?<katex_content>.+?)\n?
(?<!\\)
(?<katex_close>
\\\]
)\n?
)
|
(?:
(?<!\\)
(?<katex_open>\\\()
\n?
(?<katex_content>.+?)\n?
(?<!\\)
(?<katex_close>
\\\)
)\n?
)
)
"""#
let regex = try! NSRegularExpression(pattern: pattern, options: [.anchorsMatchLines, .allowCommentsAndWhitespace, .dotMatchesLineSeparators])
let testString = #"""
$$
\Gamma(z) = \int_0^\infty t^{z-1}e^{-t}dt\,.
$$
This is some text $math \frac12$
other text $\unsupported$
Other node \[ displaymath \\[\\] \frac{1}{2} \] blah
$$ \int_2^3 $$
more text \(and math\) blah
And $math with a
\$ sign$.
This should not match↓
$$$
\Gamma(z) = \int_0^\infty t^{z-1}e^{-t}dt\,.
$$$
This should not match either
$$
\Gamma(z) = \int_0^\infty t^{z-1}e^{-t}dt\,.
$
"""#
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