import Foundation
let pattern = #"""
{%\ (if)[\s\S]*?{%\ end\1\ %}|
{%.+?%}|
{{.+?}}
"""#
let regex = try! NSRegularExpression(pattern: pattern, options: .allowCommentsAndWhitespace)
let testString = #"""
<div class="post-preview">
<div class="post-title">
<div class="post-name">
<a href="{{ post.url }}">{{ post.title }}</a>
</div>
<div class="post-date">
{% include time.html %}
</div>
</div>
<div class="post-snippet">
{% if post.content contains '<!--break-->' %}
{{ post.content | split:'<!--break-->' | first }}
<div class="post-readmore">
<a href="{{ post.url }}">read more-></a>
</div>
{% endif %}
</div>
{% include post-meta.html %}
</div>
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let substitutionString = #""#
let result = regex.stringByReplacingMatches(in: testString, range: stringRange, withTemplate: substitutionString)
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