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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2006-2013, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala.collection
package mutable
import java.lang.{ StringBuilder => JavaStringBuilder }
import scala.annotation.migration
import immutable.StringLike
/** A builder for mutable sequence of characters. This class provides an API
* mostly compatible with `java.lang.StringBuilder`, except where there are
* conflicts with the Scala collections API (such as the `reverse` method.)
*
* @author Stephane Micheloud
* @author Martin Odersky
* @version 2.8
* @since 2.7
* @see [[http://docs.scala-lang.org/overviews/collections/concrete-mutable-collection-classes.html# "Scala's Collection Library overview"]]
* section on `StringBuilders` for more information.
*/
@SerialVersionUID(0 - 8525408645367278351L)
final class StringBuilder(private val underlying: JavaStringBuilder)
extends AbstractSeq[Char]
with java.lang.CharSequence
with IndexedSeq[Char]
with StringLike[StringBuilder]
with Builder[Char, String]
with Serializable {
override protected[this] def thisCollection: StringBuilder = this
override protected[this] def toCollection(repr: StringBuilder): StringBuilder = repr
/** Creates a string builder buffer as builder for this class */
override protected[this] def newBuilder = new GrowingBuilder(new StringBuilder)
/** Constructs a string builder initialized with string value `initValue`
* and with additional character capacity `initCapacity`.
*/
def this(initCapacity: Int, initValue: String) =
this(new JavaStringBuilder(initValue.length + initCapacity) append initValue)
/** Constructs a string builder with no characters in it and an
* initial capacity of 16 characters.
*/
def this() = this(16, "")
/** Constructs a string builder with no characters in it and an
* initial capacity specified by the `capacity` argument.
*
* @param capacity the initial capacity.
* @throws NegativeArraySizeException if capacity < 0.
*/
def this(capacity: Int) = this(capacity, "")
/** Constructs a string builder with initial characters
* equal to characters of `str`.
*/
def this(str: String) = this(16, str)
def toArray: Array[Char] = {
val arr = new Array[Char](length)
underlying.getChars(0, length, arr, 0)
arr
}
override def length: Int = underlying.length()
def length_=(n: Int) { underlying.setLength(n) }
/** Clears the builder contents.
*/
def clear(): Unit = setLength(0)
/** Sets the length of the character sequence. If the current sequence
* is shorter than the given length, it is padded with nulls; if it is
* longer, it is truncated.
*
* @param len the new length
* @throws IndexOutOfBoundsException if the argument is negative.
*/
def setLength(len: Int) { underlying setLength len }
/** Returns the current capacity, which is the size of the underlying array.
* A new array will be allocated if the current capacity is exceeded.
*
* @return the capacity
*/
def capacity: Int = underlying.capacity()
/** Ensure that the capacity is at least the given argument.
* If the argument is greater than the current capacity, new
* storage will be allocated with size equal to the given
* argument or to `(2 * capacity + 2)`, whichever is larger.
*
* @param newCapacity the minimum desired capacity.
*/
def ensureCapacity(newCapacity: Int) { underlying ensureCapacity newCapacity }
/** Returns the Char at the specified index, counting from 0 as in Arrays.
*
* @param index the index to look up
* @return the Char at the given index.
* @throws IndexOutOfBoundsException if the index is out of bounds.
*/
def charAt(index: Int): Char = underlying charAt index
/** Equivalent to charAt.
*/
override def apply(index: Int): Char = underlying charAt index
/** Removes the Char at the specified index. The sequence is
* shortened by one.
*
* @param index The index to remove.
* @return This StringBuilder.
* @throws IndexOutOfBoundsException if the index is out of bounds.
*/
def deleteCharAt(index: Int): StringBuilder = {
underlying deleteCharAt index
this
}
/** Update the sequence at the given index to hold the specified Char.
*
* @param index the index to modify.
* @param ch the new Char.
* @throws IndexOutOfBoundsException if the index is out of bounds.
*/
def setCharAt(index: Int, ch: Char): Unit = underlying.setCharAt(index, ch)
/** Equivalent to setCharAt.
*/
def update(i: Int, c: Char): Unit = setCharAt(i, c)
/** Returns a new String made up of a subsequence of this sequence,
* beginning at the given index and extending to the end of the sequence.
*
* target.substring(start) is equivalent to target.drop(start)
*
* @param start The starting index, inclusive.
* @return The new String.
* @throws IndexOutOfBoundsException if the index is out of bounds.
*/
def substring(start: Int): String = substring(start, length)
/** Returns a new String made up of a subsequence of this sequence,
* beginning at the start index (inclusive) and extending to the
* end index (exclusive).
*
* target.substring(start, end) is equivalent to target.slice(start, end).mkString
*
* @param start The beginning index, inclusive.
* @param end The ending index, exclusive.
* @return The new String.
* @throws StringIndexOutOfBoundsException If either index is out of bounds,
* or if start > end.
*/
def substring(start: Int, end: Int): String = underlying.substring(start, end)
/** For implementing CharSequence.
*/
def subSequence(start: Int, end: Int): java.lang.CharSequence =
substring(start, end)
/** Appends the given Char to the end of the sequence.
*/
def +=(x: Char): this.type = { append(x); this }
/** Optimization.
*/
def ++=(s: String): this.type = {
underlying append s
this
}
def appendAll(xs: String): StringBuilder = {
underlying append xs
this
}
/** !!! This should create a new sequence.
*/
def +(x: Char): this.type = { +=(x); this }
/** Appends the string representation of the given argument,
* which is converted to a String with `String.valueOf`.
*
* @param x an `Any` object.
* @return this StringBuilder.
*/
def append(x: Any): StringBuilder = {
underlying append String.valueOf(x)
this
}
/** Appends the given String to this sequence.
*
* @param s a String.
* @return this StringBuilder.
*/
def append(s: String): StringBuilder = {
underlying append s
this
}
/** Appends the specified string builder to this sequence.
*
* @param sb
* @return
*/
def append(sb: StringBuilder): StringBuilder = {
underlying append sb
this
}
/** Appends all the Chars in the given Seq[Char] to this sequence.
*
* @param xs the characters to be appended.
* @return this StringBuilder.
*/
def appendAll(xs: TraversableOnce[Char]): StringBuilder = appendAll(xs.toArray)
/** Appends all the Chars in the given Array[Char] to this sequence.
*
* @param xs the characters to be appended.
* @return a reference to this object.
*/
def appendAll(xs: Array[Char]): StringBuilder = {
underlying append xs
this
}
/** Appends a portion of the given Array[Char] to this sequence.
*
* @param xs the Array containing Chars to be appended.
* @param offset the index of the first Char to append.
* @param len the numbers of Chars to append.
* @return this StringBuilder.
*/
def appendAll(xs: Array[Char], offset: Int, len: Int): StringBuilder = {
underlying.append(xs, offset, len)
this
}
/** Append the String representation of the given primitive type
* to this sequence. The argument is converted to a String with
* String.valueOf.
*
* @param x a primitive value
* @return This StringBuilder.
*/
def append(x: Boolean): StringBuilder = { underlying append x ; this }
def append(x: Byte): StringBuilder = { underlying append x ; this }
def append(x: Short): StringBuilder = { underlying append x ; this }
def append(x: Int): StringBuilder = { underlying append x ; this }
def append(x: Long): StringBuilder = { underlying append x ; this }
def append(x: Float): StringBuilder = { underlying append x ; this }
def append(x: Double): StringBuilder = { underlying append x ; this }
def append(x: Char): StringBuilder = { underlying append x ; this }
/** Remove a subsequence of Chars from this sequence, starting at the
* given start index (inclusive) and extending to the end index (exclusive)
* or to the end of the String, whichever comes first.
*
* @param start The beginning index, inclusive.
* @param end The ending index, exclusive.
* @return This StringBuilder.
* @throws StringIndexOutOfBoundsException if start < 0 || start > end
*/
def delete(start: Int, end: Int): StringBuilder = {
underlying.delete(start, end)
this
}
/** Replaces a subsequence of Chars with the given String. The semantics
* are as in delete, with the String argument then inserted at index 'start'.
*
* @param start The beginning index, inclusive.
* @param end The ending index, exclusive.
* @param str The String to be inserted at the start index.
* @return This StringBuilder.
* @throws StringIndexOutOfBoundsException if start < 0, start > length, or start > end
*/
def replace(start: Int, end: Int, str: String): StringBuilder = {
underlying.replace(start, end, str)
this
}
/** Inserts a subarray of the given Array[Char] at the given index
* of this sequence.
*
* @param index index at which to insert the subarray.
* @param str the Array from which Chars will be taken.
* @param offset the index of the first Char to insert.
* @param len the number of Chars from 'str' to insert.
* @return This StringBuilder.
*
* @throws StringIndexOutOfBoundsException if index < 0, index > length,
* offset < 0, len < 0, or (offset + len) > str.length.
*/
def insertAll(index: Int, str: Array[Char], offset: Int, len: Int): StringBuilder = {
underlying.insert(index, str, offset, len)
this
}
/** Inserts the String representation (via String.valueOf) of the given
* argument into this sequence at the given index.
*
* @param index the index at which to insert.
* @param x a value.
* @return this StringBuilder.
* @throws StringIndexOutOfBoundsException if the index is out of bounds.
*/
def insert(index: Int, x: Any): StringBuilder = insert(index, String.valueOf(x))
/** Inserts the String into this character sequence.
*
* @param index the index at which to insert.
* @param x a String.
* @return this StringBuilder.
* @throws StringIndexOutOfBoundsException if the index is out of bounds.
*/
def insert(index: Int, x: String): StringBuilder = {
underlying.insert(index, x)
this
}
/** Inserts the given Seq[Char] into this sequence at the given index.
*
* @param index the index at which to insert.
* @param xs the Seq[Char].
* @return this StringBuilder.
* @throws StringIndexOutOfBoundsException if the index is out of bounds.
*/
def insertAll(index: Int, xs: TraversableOnce[Char]): StringBuilder = insertAll(index, xs.toArray)
/** Inserts the given Array[Char] into this sequence at the given index.
*
* @param index the index at which to insert.
* @param xs the Array[Char].
* @return this StringBuilder.
* @throws StringIndexOutOfBoundsException if the index is out of bounds.
*/
def insertAll(index: Int, xs: Array[Char]): StringBuilder = {
underlying.insert(index, xs)
this
}
/** Calls String.valueOf on the given primitive value, and inserts the
* String at the given index.
*
* @param index the offset position.
* @param x a primitive value.
* @return this StringBuilder.
*/
def insert(index: Int, x: Boolean): StringBuilder = insert(index, String.valueOf(x))
def insert(index: Int, x: Byte): StringBuilder = insert(index, String.valueOf(x))
def insert(index: Int, x: Short): StringBuilder = insert(index, String.valueOf(x))
def insert(index: Int, x: Int): StringBuilder = insert(index, String.valueOf(x))
def insert(index: Int, x: Long): StringBuilder = insert(index, String.valueOf(x))
def insert(index: Int, x: Float): StringBuilder = insert(index, String.valueOf(x))
def insert(index: Int, x: Double): StringBuilder = insert(index, String.valueOf(x))
def insert(index: Int, x: Char): StringBuilder = insert(index, String.valueOf(x))
/** Finds the index of the first occurrence of the specified substring.
*
* @param str the target string to search for
* @return the first applicable index where target occurs, or -1 if not found.
*/
def indexOf(str: String): Int = underlying.indexOf(str)
/** Finds the index of the first occurrence of the specified substring.
*
* @param str the target string to search for
* @param fromIndex the smallest index in the source string to consider
* @return the first applicable index where target occurs, or -1 if not found.
*/
def indexOf(str: String, fromIndex: Int): Int = underlying.indexOf(str, fromIndex)
/** Finds the index of the last occurrence of the specified substring.
*
* @param str the target string to search for
* @return the last applicable index where target occurs, or -1 if not found.
*/
def lastIndexOf(str: String): Int = underlying.lastIndexOf(str)
/** Finds the index of the last occurrence of the specified substring.
*
* @param str the target string to search for
* @param fromIndex the smallest index in the source string to consider
* @return the last applicable index where target occurs, or -1 if not found.
*/
def lastIndexOf(str: String, fromIndex: Int): Int = underlying.lastIndexOf(str, fromIndex)
/** Creates a new StringBuilder with the reversed contents of this one.
* If surrogate pairs are present, they are treated as indivisible units: each
* pair will appear in the same order in the updated sequence.
*
* @return the reversed StringBuilder
*/
@migration("`reverse` returns a new instance. Use `reverseContents` to update in place and return that StringBuilder itself.", "2.8.0")
override def reverse: StringBuilder = new StringBuilder(new JavaStringBuilder(underlying).reverse)
override def clone(): StringBuilder = new StringBuilder(new JavaStringBuilder(underlying))
/** Like reverse, but destructively updates the target StringBuilder.
*
* @return the reversed StringBuilder (same as the target StringBuilder)
*/
def reverseContents(): StringBuilder = {
underlying.reverse()
this
}
/** Returns a new String representing the data in this sequence.
*
* @note because toString is inherited from AnyRef and used for
* many purposes, it is better practice to call mkString
* to obtain a StringBuilder result.
* @return the current contents of this sequence as a String
*/
override def toString = underlying.toString
/** Returns a new String representing the data in this sequence.
*
* @return the current contents of this sequence as a String
*/
override def mkString = toString
/** Returns the result of this Builder (a String)
*
* @return the string assembled by this StringBuilder
*/
def result(): String = toString
}
object StringBuilder {
def newBuilder = new StringBuilder
}
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