Regular expressions: Difference between revisions

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=={{header|Scala}}==

[[Category:Scala Implementations]]

Define

<lang ~~scala~~>val Bottles1 = "(\\d+) bottles of beer".r // syntactic sugar

<lang Scala>val Bottles1 = "(\\d+) bottles of beer".r // syntactic sugar

val Bottles2 = """(\d+) bottles of beer""".r // using triple-quotes to preserve backslashes

val Bottles3 = new scala.util.matching.Regex("(\\d+) bottles of beer") // standard

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Bottles4 findFirstMatchIn "99 bottles of beer" // returns a "Match" object, or None

Bottles4 findPrefixMatchOf "99 bottles of beer" // same thing, for prefixes

val bottles = (Bottles4 findFirstMatchIn "99 bottles of beer").get.group("bottles") // Getting a group by name

val bottles = (Bottles4 findFirstMatchIn "99 bottles of beer").get.group("bottles") // Getting a group by name</lang>

val Bottles4(bottles) = "99 bottles of beer" // syntactic sugar (not using group name)</lang>

Using pattern matching with regex:

<lang ~~scala~~>val Some(bottles) = Bottles4 findPrefixOf "99 bottles of beer" // throws an exception if the matching fails; full string must match

<lang Scala>val Some(bottles) = Bottles4 findPrefixOf "99 bottles of beer" // throws an exception if the matching fails; full string must match

for {

line <- """|99 bottles of beer on the wall

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Replacing with regex:

<lang ~~scala~~>Bottles2 replaceFirstIn ("99 bottles of beer", "98 bottles of beer")

<lang Scala>Bottles2 replaceFirstIn ("99 bottles of beer", "98 bottles of beer")

Bottles3 replaceAllIn ("99 bottles of beer", "98 bottles of beer")</lang>