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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2018-2023 Saxonica Limited
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
package net.sf.saxon.str;
import net.sf.saxon.serialize.UTF8Writer;
import net.sf.saxon.z.ConcatenatingIntIterator;
import net.sf.saxon.z.IntIterator;
import net.sf.saxon.z.IntRepeatIterator;
import java.util.Arrays;
/**
* This class provides a compressed representation of a string used to represent indentation: specifically,
* an integer number of newlines followed by an integer number of spaces. It's a little cheaper than
* the {@link CompressedWhitespace} class, and is specifically used for constructing indentation and passing
* it to a {@link UTF8Writer}, which recognizes it specially. Unlike {@link CompressedWhitespace}, it can't
* handle arbitrary whitespace strings, only those consisting of newlines followed by spaces.
*/
public class IndentWhitespace extends WhitespaceString {
private final int newlines;
private final int spaces;
private IndentWhitespace(int newlines, int spaces) {
this.newlines = newlines;
this.spaces = spaces;
}
/**
* Create an IndentWhitespace object
* @param newlines the number of newlines at the start
* @param spaces the number of spaces following the newlines
* @return the constructed (or potentially cached) IndentWhitespace object
*/
public static IndentWhitespace of(int newlines, int spaces) {
// Uses a factory method to permit pooling, not currently implemented
return new IndentWhitespace(newlines, spaces);
}
/**
* Uncompress the whitespace to a (normal) UnicodeString
* @return the uncompressed value
*/
@Override
public UnicodeString uncompress() {
byte[] bytes = new byte[newlines + spaces];
Arrays.fill(bytes, 0, newlines, (byte)0x0a);
Arrays.fill(bytes, newlines, newlines + spaces, (byte)0x20);
return new Twine8(bytes);
}
@Override
public long length() {
return newlines + spaces;
}
@Override
public int length32() {
return newlines + spaces;
}
/**
* Get the number of newlines at the start
* @return the number of newline characters
*/
public int getNewlines() {
return newlines;
}
/**
* Get the number of spaces following the newlines
* @return the number of space characters
*/
public int getSpaces() {
return spaces;
}
/**
* Returns the codepoint value at the specified index. An index ranges from zero
* to length() - 1. The first codepoint value of the sequence is at
* index zero, the next at index one, and so on, as for array
* indexing.
*
* @param index the index of the codepoint value to be returned
* @return the specified codepoint value
* @throws IndexOutOfBoundsException if the index argument is negative or not less than
* length()
*/
@Override
public int codePointAt(long index) {
if (index >= 0 && index < newlines) {
return 0x0A;
} else if (index <= newlines + spaces) {
return 0x20;
} else {
throw new IndexOutOfBoundsException();
}
}
@Override
public IntIterator codePoints() {
return new ConcatenatingIntIterator(
new IntRepeatIterator(10, newlines),
() -> new IntRepeatIterator(32, spaces));
}
/**
* Returns a string representation of the object.
*/
public String toString() {
char[] chars = new char[newlines + spaces];
Arrays.fill(chars, 0, newlines, '\n');
Arrays.fill(chars, newlines, newlines + spaces, ' ');
return new String(chars);
}
/**
* Write the value to a UnicodeWriter
*
* @param writer the writer to write to
* @throws java.io.IOException if an error occurs downstream
*/
@Override
public void write(/*@NotNull*/ UnicodeWriter writer) throws java.io.IOException {
if (newlines > 0) {
writer.writeRepeatedAscii((byte) 0x0A, newlines);
}
if (spaces > 0) {
writer.writeRepeatedAscii((byte) 0x20, spaces);
}
}
/**
* Write the value to a Writer with escaping of special characters
*
* @param specialChars identifies which characters are considered special
* @param writer the writer to write to
* @throws java.io.IOException if an error occurs downstream
*/
@Override
public void writeEscape(boolean[] specialChars, UnicodeWriter writer) throws java.io.IOException {
if (specialChars[0x0A]) {
for (int i=0; i