Class scala.util.matching.Regex

Test two objects for inequality.

Equivalent to x.hashCode except for boxed numeric types and null. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null returns a hashcode where null.hashCode throws a NullPointerException.

The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).

Cast the receiver object to be of type T0.

Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expression List(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.

Create a copy of the receiver object.

The default implementation of the clone method is platform dependent.

Tests whether the argument (that) is a reference to the receiver object (this).

The eq method implements an equivalence relation on non-null instances of AnyRef, and has three additional properties:

It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false.For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false. null.eq(null) returns true.

When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).

The equality method for reference types. Default implementation delegates to eq.

See also equals in scala.Any.

Called by the garbage collector on the receiver object when there are no more references to the object.

The details of when and if the finalize method is invoked, as well as the interaction between finalize and non-local returns and exceptions, are all platform dependent.

Return all non-overlapping matches of this Regex in the given character sequence as a scala.util.matching.Regex.MatchIterator, which is a special scala.collection.Iterator that returns the matched strings but can also be queried for more data about the last match, such as capturing groups and start position.

A MatchIterator can also be converted into an iterator that returns objects of type scala.util.matching.Regex.Match, such as is normally returned by findAllMatchIn.

Where potential matches overlap, the first possible match is returned, followed by the next match that follows the input consumed by the first match:

val hat  = "hat[^a]+".r
val hathaway = "hathatthattthatttt"
val hats = hat.findAllIn(hathaway).toList                     // List(hath, hattth)
val pos  = hat.findAllMatchIn(hathaway).map(_.start).toList   // List(0, 7)

To return overlapping matches, it is possible to formulate a regular expression with lookahead (?=) that does not consume the overlapping region.

val madhatter = "(h)(?=(at[^a]+))".r
val madhats   = madhatter.findAllMatchIn(hathaway).map {
  case madhatter(x,y) => s"$x$y"
}.toList                                       // List(hath, hatth, hattth, hatttt)

Attempting to retrieve match information after exhausting the iterator results in java.lang.IllegalStateException. See scala.util.matching.Regex.MatchIterator for details.

Return all non-overlapping matches of this regexp in given character sequence as a scala.collection.Iterator of scala.util.matching.Regex.Match.

Return an optional first matching string of this Regex in the given character sequence, or None if there is no match.

Return an optional first match of this Regex in the given character sequence, or None if it does not exist.

If the match is successful, the scala.util.matching.Regex.Match can be queried for more data.

Return an optional match of this Regex at the beginning of the given character sequence, or None if it matches no prefix of the character sequence.

Unlike findFirstMatchIn, this method will only return a match at the beginning of the input.

Return an optional match of this Regex at the beginning of the given character sequence, or None if it matches no prefix of the character sequence.

Unlike findFirstIn, this method will only return a match at the beginning of the input.

Returns string formatted according to given format string. Format strings are as for String.format (@see java.lang.String.format).

Returns the runtime class representation of the object.

The hashCode method for reference types. See hashCode in scala.Any.

Test whether the dynamic type of the receiver object is T0.

Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.

Returns whether this Regex matches the given character sequence.

Like the extractor, this method takes anchoring into account.

Equivalent to !(this eq that).

Wakes up a single thread that is waiting on the receiver object's monitor.

Wakes up all threads that are waiting on the receiver object's monitor.

Replaces all matches using a replacer function. The replacer function takes a scala.util.matching.Regex.Match so that extra information can be obtained from the match. For example:

import scala.util.matching.Regex
val datePattern = new Regex("""(\d\d\d\d)-(\d\d)-(\d\d)""", "year", "month", "day")
val text = "From 2011-07-15 to 2011-07-17"
val repl = datePattern replaceAllIn (text, m => s"${m group "month"}/${m group "day"}")

In the replacement String, a dollar sign ($) followed by a number will be interpreted as a reference to a group in the matched pattern, with numbers 1 through 9 corresponding to the first nine groups, and 0 standing for the whole match. Any other character is an error. The backslash (\) character will be interpreted as an escape character and can be used to escape the dollar sign. Use Regex.quoteReplacement to escape these characters.

Replaces all matches by a string.

In the replacement String, a dollar sign ($) followed by a number will be interpreted as a reference to a group in the matched pattern, with numbers 1 through 9 corresponding to the first nine groups, and 0 standing for the whole match. Any other character is an error. The backslash (\) character will be interpreted as an escape character and can be used to escape the dollar sign. Use Regex.quoteReplacement to escape these characters.

Replaces the first match by a string.

In the replacement String, a dollar sign ($) followed by a number will be interpreted as a reference to a group in the matched pattern, with numbers 1 through 9 corresponding to the first nine groups, and 0 standing for the whole match. Any other character is an error. The backslash (\) character will be interpreted as an escape character and can be used to escape the dollar sign. Use Regex.quoteReplacement to escape these characters.

Replaces some of the matches using a replacer function that returns an scala.Option. The replacer function takes a scala.util.matching.Regex.Match so that extra information can be obtained from the match. For example:

import scala.util.matching.Regex._

val vars = Map("x" -> "a var", "y" -> """some $ and \ signs""")
val text = "A text with variables %x, %y and %z."
val varPattern = """%(\w+)""".r
val mapper = (m: Match) => vars get (m group 1) map (quoteReplacement(_))
val repl = varPattern replaceSomeIn (text, mapper)

In the replacement String, a dollar sign ($) followed by a number will be interpreted as a reference to a group in the matched pattern, with numbers 1 through 9 corresponding to the first nine groups, and 0 standing for the whole match. Any other character is an error. The backslash (\) character will be interpreted as an escape character and can be used to escape the dollar sign. Use Regex.quoteReplacement to escape these characters.

Splits the provided character sequence around matches of this regexp.

The string defining the regular expression

Create a new Regex with the same pattern, but no requirement that the entire String matches in extractor patterns and Regex#matches.

Normally, matching on date behaves as though the pattern were enclosed in anchors, "^pattern$".

The unanchored Regex behaves as though those anchors were removed.

Note that this method does not actually strip any matchers from the pattern.

Calling anchored returns the original Regex.

val date = """(\d\d\d\d)-(\d\d)-(\d\d)""".r.unanchored

val date(year, month, day) = "Date 2011-07-15"                       // OK

val copyright: String = "Date of this document: 2011-07-15" match {
  case date(year, month, day) => s"Copyright $year"                  // OK
  case _                      => "No copyright"
}

Tries to match on a scala.util.matching.Regex.Match.

A previously failed match results in None.

If a successful match was made against the current pattern, then that result is used.

Otherwise, this Regex is applied to the previously matched input, and the result of that match is used.

Tries to match the String representation of a scala.Char.

If the match succeeds, the result is the first matching group if any groups are defined, or an empty Sequence otherwise.

For example:

val cat = "cat"
// the case must consume the group to match
val r = """(\p{Lower})""".r
cat(0) match { case r(x) => true }
cat(0) match { case r(_) => true }
cat(0) match { case r(_*) => true }
cat(0) match { case r() => true }     // no match

// there is no group to extract
val r = """\p{Lower}""".r
cat(0) match { case r(x) => true }    // no match
cat(0) match { case r(_) => true }    // no match
cat(0) match { case r(_*) => true }   // matches
cat(0) match { case r() => true }     // matches

// even if there are multiple groups, only one is returned
val r = """((.))""".r
cat(0) match { case r(_) => true }    // matches
cat(0) match { case r(_,_) => true }  // no match

Tries to match a java.lang.CharSequence.

If the match succeeds, the result is a list of the matching groups (or a null element if a group did not match any input). If the pattern specifies no groups, then the result will be an empty list on a successful match.

This method attempts to match the entire input by default; to find the next matching subsequence, use an unanchored Regex.

For example:

val p1 = "ab*c".r
val p1Matches = "abbbc" match {
  case p1() => true               // no groups
  case _    => false
}
val p2 = "a(b*)c".r
val p2Matches = "abbbc" match {
  case p2(_*) => true             // any groups
  case _      => false
}
val numberOfB = "abbbc" match {
  case p2(b) => Some(b.length)    // one group
  case _     => None
}
val p3 = "b*".r.unanchored
val p3Matches = "abbbc" match {
  case p3() => true               // find the b's
  case _    => false
}
val p4 = "a(b*)(c+)".r
val p4Matches = "abbbcc" match {
  case p4(_*) => true             // multiple groups
  case _      => false
}
val allGroups = "abbbcc" match {
  case p4(all @ _*) => all mkString "/" // "bbb/cc"
  case _            => ""
}
val cGroup = "abbbcc" match {
  case p4(_, c) => c
  case _        => ""
}