import Foundation
let pattern = #"\(\s*define\s*(\(.*?\))"#
let regex = try! NSRegularExpression(pattern: pattern, options: [.anchorsMatchLines, .dotMatchesLineSeparators])
let testString = ##"""
#lang sicp
(define (square x) (* x x))
(define (average x y) (/ (+ x y) 2))
; using block scope
(define (sqrt x)
; x is always the same -- "4" or whatever we pass to it, so we don't need that
; in every single function that we define, we can just inherit it from above.
(define (improve guess) (average guess (/ x guess)))
(define (good-enough? guess) (< (abs (- (square guess) x)) 0.001 ))
(define (sqrt-iter guess) (if (good-enough? guess) guess (sqrt-iter (improve guess))))
(sqrt-iter 1.0)
)
(sqrt 4)
(define (inc x) (+ x 1))
(define (dec x) (- x 1))
"""##
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