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/*
* Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package com.sun.tools.javac.parser;
import java.util.HashSet;
import java.util.Set;
import nbjavac.StringWrapper;
/**
* Methods used to support text blocks lint.
*
* This is NOT part of any supported API.
* If you write code that depends on this, you do so at your own risk.
* This code and its internal interfaces are subject to change or
* deletion without notice.
*/
class TextBlockSupport {
enum WhitespaceChecks {
INCONSISTENT,
TRAILING
};
/** Check that the use of white space in content is not problematic.
*/
static Set checkWhitespace(String string) {
// Start with empty result set.
Set checks = new HashSet<>();
// No need to check empty strings.
if (string.isEmpty()) {
return checks;
}
// Maximum common indentation.
int outdent = 0;
// No need to check indentation if opting out (last line is empty.)
char lastChar = string.charAt(string.length() - 1);
boolean optOut = lastChar == '\n' || lastChar == '\r';
// Split string based at line terminators.
String[] lines = string.split("\\R");
int length = lines.length;
// Extract last line.
String lastLine = length == 0 ? "" : lines[length - 1];
if (!optOut) {
// Prime with the last line indentation (may be blank.)
outdent = indexOfNonWhitespace(lastLine);
for (String line : lines) {
// Blanks lines have no influence (last line accounted for.)
if (!StringWrapper.isBlank(line)) {
outdent = Integer.min(outdent, indexOfNonWhitespace(line));
if (outdent == 0) {
break;
}
}
}
}
// Last line is representative.
String start = lastLine.substring(0, outdent);
for (String line : lines) {
// Fail if a line does not have the same indentation.
if (!StringWrapper.isBlank(line) && !line.startsWith(start)) {
// Mix of different white space
checks.add(WhitespaceChecks.INCONSISTENT);
}
// Line has content even after indent is removed.
if (outdent < line.length()) {
// Is the last character a white space.
lastChar = line.charAt(line.length() - 1);
if (Character.isWhitespace(lastChar)) {
// Has trailing white space.
checks.add(WhitespaceChecks.TRAILING);
}
}
}
return checks;
}
private static int indexOfNonWhitespace(String string) {
return string.length() - string.replaceAll("^\\p{javaWhitespace}+", "").length();
}
}