import Foundation
let pattern = #"(?:[!]\[(?P<caption>.*?)\])\((?P<image>.*?)\)"#
let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines)
let testString = ###"""
This is a regex to detect markdown image links of the form 
Here are some markdown links
- [pandoc-fignos](https://github.com/tomduck/pandoc-fignos): Numbers figures and figure references.
The images section will walk you through how to add and reference images so that the pandoc system can properly number them. For example, this [figure](./ch0_1_images.md#fig:ch0_1_images-1) illustrates a VOD curve for a packaged watergel explosive and this [figure](./ch0_1_images.md#fig:ch0_1_images-2) depicts a circular arc.
## [Equations](./ch0_2_equations.md#sec:ch0_2_equations-1)
The equations section will discuss how to use equations and reference them properly. See the [internal energy equation](./ch0_2_equations.md#eq:ch0_2_equations-1) or the [detonation pressure](./ch0_2_equations.md#eq:ch0_2_equations-2)
This string does not contain any links
Here are some image links:
{#fig:id}
{#fig:id tag="B.1"}
{#fig:ch0_1_images-1 width=100%}
"""###
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