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Kotlin Standard Library for JVM
/*
* Copyright 2010-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
* that can be found in the license/LICENSE.txt file.
*/
package kotlin.text
import java.util.Collections
import java.util.EnumSet
import java.util.regex.Matcher
import java.util.regex.Pattern
import kotlin.internal.IMPLEMENTATIONS
private interface FlagEnum {
public val value: Int
public val mask: Int
}
private fun Iterable.toInt(): Int =
this.fold(0, { value, option -> value or option.value })
private inline fun fromInt(value: Int): Set where T : FlagEnum, T : Enum =
Collections.unmodifiableSet(EnumSet.allOf(T::class.java).apply {
retainAll { value and it.mask == it.value }
})
/**
* Provides enumeration values to use to set regular expression options.
*/
public actual enum class RegexOption(override val value: Int, override val mask: Int = value) : FlagEnum {
// common
/** Enables case-insensitive matching. Case comparison is Unicode-aware. */
IGNORE_CASE(Pattern.CASE_INSENSITIVE),
/** Enables multiline mode.
*
* In multiline mode the expressions `^` and `$` match just after or just before,
* respectively, a line terminator or the end of the input sequence. */
MULTILINE(Pattern.MULTILINE),
//jvm-specific
/** Enables literal parsing of the pattern.
*
* Metacharacters or escape sequences in the input sequence will be given no special meaning.
*/
LITERAL(Pattern.LITERAL),
// // Unicode case is enabled by default with the IGNORE_CASE
// /** Enables Unicode-aware case folding. */
// UNICODE_CASE(Pattern.UNICODE_CASE)
/** Enables Unix lines mode.
* In this mode, only the `'\n'` is recognized as a line terminator.
*/
UNIX_LINES(Pattern.UNIX_LINES),
/** Permits whitespace and comments in pattern. */
COMMENTS(Pattern.COMMENTS),
/** Enables the mode, when the expression `.` matches any character,
* including a line terminator.
*/
DOT_MATCHES_ALL(Pattern.DOTALL),
/** Enables equivalence by canonical decomposition. */
CANON_EQ(Pattern.CANON_EQ)
}
/**
* Represents the results from a single capturing group within a [MatchResult] of [Regex].
*
* @param value The value of captured group.
* @param range The range of indices in the input string where group was captured.
*
* The [range] property is available on JVM only.
*/
public actual data class MatchGroup(public actual val value: String, public val range: IntRange)
/**
* Represents an immutable regular expression.
*
* For pattern syntax reference see [Pattern]
*/
public actual class Regex
@PublishedApi
internal constructor(private val nativePattern: Pattern) : Serializable {
/** Creates a regular expression from the specified [pattern] string and the default options. */
public actual constructor(pattern: String) : this(Pattern.compile(pattern))
/** Creates a regular expression from the specified [pattern] string and the specified single [option]. */
public actual constructor(pattern: String, option: RegexOption) : this(Pattern.compile(pattern, ensureUnicodeCase(option.value)))
/** Creates a regular expression from the specified [pattern] string and the specified set of [options]. */
public actual constructor(pattern: String, options: Set) : this(Pattern.compile(pattern, ensureUnicodeCase(options.toInt())))
/** The pattern string of this regular expression. */
public actual val pattern: String
get() = nativePattern.pattern()
private var _options: Set? = null
/** The set of options that were used to create this regular expression. */
public actual val options: Set get() = _options ?: fromInt(nativePattern.flags()).also { _options = it }
/** Indicates whether the regular expression matches the entire [input]. */
public actual infix fun matches(input: CharSequence): Boolean = nativePattern.matcher(input).matches()
/** Indicates whether the regular expression can find at least one match in the specified [input]. */
public actual fun containsMatchIn(input: CharSequence): Boolean = nativePattern.matcher(input).find()
/**
* Returns the first match of a regular expression in the [input], beginning at the specified [startIndex].
*
* @param startIndex An index to start search with, by default 0. Must be not less than zero and not greater than `input.length()`
* @return An instance of [MatchResult] if match was found or `null` otherwise.
*/
@Suppress("ACTUAL_FUNCTION_WITH_DEFAULT_ARGUMENTS")
public actual fun find(input: CharSequence, startIndex: Int = 0): MatchResult? =
nativePattern.matcher(input).findNext(startIndex, input)
/**
* Returns a sequence of all occurrences of a regular expression within the [input] string, beginning at the specified [startIndex].
*/
@Suppress("ACTUAL_FUNCTION_WITH_DEFAULT_ARGUMENTS")
public actual fun findAll(input: CharSequence, startIndex: Int = 0): Sequence =
generateSequence({ find(input, startIndex) }, MatchResult::next)
/**
* Attempts to match the entire [input] CharSequence against the pattern.
*
* @return An instance of [MatchResult] if the entire input matches or `null` otherwise.
*/
public actual fun matchEntire(input: CharSequence): MatchResult? = nativePattern.matcher(input).matchEntire(input)
/**
* Replaces all occurrences of this regular expression in the specified [input] string with specified [replacement] expression.
*
* @param replacement A replacement expression that can include substitutions. See [Matcher.appendReplacement] for details.
*/
public actual fun replace(input: CharSequence, replacement: String): String = nativePattern.matcher(input).replaceAll(replacement)
/**
* Replaces all occurrences of this regular expression in the specified [input] string with the result of
* the given function [transform] that takes [MatchResult] and returns a string to be used as a
* replacement for that match.
*/
public actual fun replace(input: CharSequence, transform: (MatchResult) -> CharSequence): String {
var match: MatchResult? = find(input) ?: return input.toString()
var lastStart = 0
val length = input.length
val sb = StringBuilder(length)
do {
val foundMatch = match!!
sb.append(input, lastStart, foundMatch.range.start)
sb.append(transform(foundMatch))
lastStart = foundMatch.range.endInclusive + 1
match = foundMatch.next()
} while (lastStart < length && match != null)
if (lastStart < length) {
sb.append(input, lastStart, length)
}
return sb.toString()
}
/**
* Replaces the first occurrence of this regular expression in the specified [input] string with specified [replacement] expression.
*
* @param replacement A replacement expression that can include substitutions. See [Matcher.appendReplacement] for details.
*/
public actual fun replaceFirst(input: CharSequence, replacement: String): String =
nativePattern.matcher(input).replaceFirst(replacement)
/**
* Splits the [input] CharSequence around matches of this regular expression.
*
* @param limit Non-negative value specifying the maximum number of substrings the string can be split to.
* Zero by default means no limit is set.
*/
@Suppress("ACTUAL_FUNCTION_WITH_DEFAULT_ARGUMENTS")
public actual fun split(input: CharSequence, limit: Int = 0): List {
require(limit >= 0, { "Limit must be non-negative, but was $limit." })
val matcher = nativePattern.matcher(input)
if (!matcher.find() || limit == 1) return listOf(input.toString())
val result = ArrayList(if (limit > 0) limit.coerceAtMost(10) else 10)
var lastStart = 0
val lastSplit = limit - 1 // negative if there's no limit
do {
result.add(input.substring(lastStart, matcher.start()))
lastStart = matcher.end()
if (lastSplit >= 0 && result.size == lastSplit) break
} while (matcher.find())
result.add(input.substring(lastStart, input.length))
return result
}
/** Returns the string representation of this regular expression, namely the [pattern] of this regular expression. */
public override fun toString(): String = nativePattern.toString()
/**
* Returns an instance of [Pattern] with the same pattern string and options as this instance of [Regex] has.
*
* Provides the way to use [Regex] where [Pattern] is required.
*/
public fun toPattern(): Pattern = nativePattern
private fun writeReplace(): Any = Serialized(nativePattern.pattern(), nativePattern.flags())
private class Serialized(val pattern: String, val flags: Int) : Serializable {
companion object {
private const val serialVersionUID: Long = 0L
}
private fun readResolve(): Any = Regex(Pattern.compile(pattern, flags))
}
actual companion object {
/** Returns a literal regex for the specified [literal] string. */
public actual fun fromLiteral(literal: String): Regex = literal.toRegex(RegexOption.LITERAL)
/** Returns a literal pattern for the specified [literal] string. */
public actual fun escape(literal: String): String = Pattern.quote(literal)
/** Returns a literal replacement expression for the specified [literal] string. */
public actual fun escapeReplacement(literal: String): String = Matcher.quoteReplacement(literal)
private fun ensureUnicodeCase(flags: Int) = if (flags and Pattern.CASE_INSENSITIVE != 0) flags or Pattern.UNICODE_CASE else flags
}
}
// implementation
private fun Matcher.findNext(from: Int, input: CharSequence): MatchResult? {
return if (!find(from)) null else MatcherMatchResult(this, input)
}
private fun Matcher.matchEntire(input: CharSequence): MatchResult? {
return if (!matches()) null else MatcherMatchResult(this, input)
}
private class MatcherMatchResult(private val matcher: Matcher, private val input: CharSequence) : MatchResult {
private val matchResult = matcher.toMatchResult()
override val range: IntRange
get() = matchResult.range()
override val value: String
get() = matchResult.group()
override val groups: MatchGroupCollection = object : MatchNamedGroupCollection, AbstractCollection() {
override val size: Int get() = matchResult.groupCount() + 1
override fun isEmpty(): Boolean = false
override fun iterator(): Iterator = indices.asSequence().map { this[it] }.iterator()
override fun get(index: Int): MatchGroup? {
val range = matchResult.range(index)
return if (range.start >= 0)
MatchGroup(matchResult.group(index), range)
else
null
}
override fun get(name: String): MatchGroup? {
return IMPLEMENTATIONS.getMatchResultNamedGroup(matchResult, name)
}
}
private var groupValues_: List? = null
override val groupValues: List
get() {
if (groupValues_ == null) {
groupValues_ = object : AbstractList() {
override val size: Int get() = matchResult.groupCount() + 1
override fun get(index: Int): String = matchResult.group(index) ?: ""
}
}
return groupValues_!!
}
override fun next(): MatchResult? {
val nextIndex = matchResult.end() + if (matchResult.end() == matchResult.start()) 1 else 0
return if (nextIndex <= input.length) matcher.findNext(nextIndex, input) else null
}
}
private fun java.util.regex.MatchResult.range(): IntRange = start() until end()
private fun java.util.regex.MatchResult.range(groupIndex: Int): IntRange = start(groupIndex) until end(groupIndex)