/*
* The MIT License
*
* Copyright (c) 2009 The Broad Institute
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package htsjdk.samtools.util;
import java.util.regex.Pattern;
/**
* Implementation of LineReader that gets its input from a String. No charset conversion
* is necessary because the String is in unicode. Handles CR, LF or CRLF line termination,
* but if asked to return the line terminator, it always comes back as LF.
*/
public class StringLineReader implements LineReader {
private static final Pattern CRLF = Pattern.compile("\r\n");
private final String theString;
private int curPos = 0;
private int lineNumber = 0;
public StringLineReader(final String s) {
// Simplify later processing by replacing crlf with just lf, and replacing solo cr with lf.
// Note that String.replace(String, String) causes a regex to be used, so precompilation should be
// the best we can do short of handling the string directly.
this.theString = CRLF.matcher(s).replaceAll("\n").replace('\r', '\n');
}
/**
* Read a line and remove the line terminator
*/
public String readLine() {
return readLine(false);
}
/**
* Read a line and optionally include the line terminator
*
* @param includeTerminators
* @return the next line from the input, with \n terminator if present and requested, or null if no more input.
*/
private String readLine(final boolean includeTerminators) {
if (curPos == theString.length()) {
return null;
}
final int nextLfIndex = theString.indexOf('\n', curPos);
if (nextLfIndex == -1) {
final int startPos = curPos;
curPos = theString.length();
++lineNumber;
return theString.substring(startPos);
}
final int startPos = curPos;
final int endPos = nextLfIndex + (includeTerminators? 1: 0);
curPos = nextLfIndex + 1;
++lineNumber;
return theString.substring(startPos, endPos);
}
/**
* @return 1-based number of line most recently read
*/
public int getLineNumber() {
return lineNumber;
}
/**
* Non-destructive one-character look-ahead.
*
* @return If not eof, the next character that would be read. If eof, -1.
*/
public int peek() {
if (curPos == theString.length()) {
return -1;
}
return theString.charAt(curPos);
}
public void close() {
curPos = theString.length();
}
}