Run1 scala regex processing

String manipulation and tokenization rely heavily on Regular Expressions. Scala integrates regular expressions natively through scala.util.matching.Regex.

1. Creating Regular Expressions

Scala allows defining regex securely using raw strings ("""...""") and the .r method, avoiding the need to escape backslashes.

Python:

import re
pattern = re.compile(r'\s+')

Scala:

val whitespacePattern = """\s+""".r

2. Matching and Splitting

Python:

tokens = re.split(r'\s+', text)
matches = re.findall(r'\d+', text)

Scala:

// Splitting
val tokens: Array[String] = whitespacePattern.split(text)

// Finding all matches
val numberPattern = """\d+""".r
val matches: Iterator[String] = numberPattern.findAllIn(text)
val matchesList: List[String] = matches.toList

3. Pattern Matching with Regex

Scala allows using Regex as extractors in pattern matching:

val dateRegex = """(\d{4})-(\d{2})-(\d{2})""".r

text match {
  case dateRegex(year, month, day) => 
    println(s"Found date: Year $year, Month $month")
  case _ => 
    println("No date found")
}