/*
* Copyright (c) 2013, 2016, 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
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.oracle.truffle.api.source;
/**
* Description of contiguous section of text within a {@link Source} of program code.; supports
* multiple modes of access to the text and its location.
* <p>
* Two available source sections are considered equal if their sources, start and length are equal.
* {@link #isAvailable() Unavailable} source sections are compared by identity. Source sections can
* be used as keys in hash maps.
*
* @see Source#createSection(int)
* @see Source#createSection(int, int)
* @see Source#createSection(int, int, int)
* @see Source#createUnavailableSection()
* @since 0.8 or earlier
*/
public final class SourceSection {
private final Source source;
private final int charIndex;
private final int charLength; // -1 indicates unavailable
SourceSection(Source source, int charIndex, int charLength) {
this.source = source;
this.charIndex = charIndex;
this.charLength = charLength;
}
/**
* Returns whether this is a special instance that signifies that source information is
* available. Unavailable source sections can be created using
* {@link Source#createUnavailableSection()}. Available source sections are never equal to
* unavailable source sections. Unavailable source sections return the same indices and lengths
* as empty source sections starting at character index <code>0</code>.
*
* @see Source#createUnavailableSection()
* @since 0.18
*/
public boolean isAvailable() {
return charLength != -1;
}
/**
* Returns whether the source section is in bounds of the {@link #getSource() source}
* {@link Source#getCode() code}. Please note that calling this method causes the
* {@link Source#getCode() code} of the {@link #getSource() source} to be loaded if it was not
* yet loaded.
*/
boolean isValid() {
return isAvailable() ? (charIndex + charLength <= getSource().getCode().length()) : false;
}
/**
* Representation of the source program that contains this section.
*
* @return the source object
* @since 0.8 or earlier
*/
public Source getSource() {
return source;
}
/**
* Returns 1-based line number of the first character in this section (inclusive). Returns
* <code>1</code> for out of bounds or {@link #isAvailable() unavailable} source sections.
* Please note that calling this method causes the {@link Source#getCode() code} of the
* {@link #getSource() source} to be loaded if it was not yet loaded.
*
* @return the starting line number
* @since 0.8 or earlier
*/
public int getStartLine() {
if (source == null) {
return -1;
}
if (!isValid()) {
return 1;
}
return source.getLineNumber(getCharIndex());
}
/**
* Returns the 1-based column number of the first character in this section (inclusive). Returns
* <code>1</code> for out of bounds or {@link #isAvailable() unavailable} source sections.
* Please note that calling this method causes the {@link Source#getCode() code} of the
* {@link #getSource() source} to be loaded if it was not yet loaded.
*
* @return the starting column number
* @since 0.8 or earlier
*/
public int getStartColumn() {
if (source == null) {
return -1;
}
if (!isValid()) {
return 1;
}
return source.getColumnNumber(getCharIndex());
}
/**
* Gets a representation of the {@link #getStartLine() first line} of the section, suitable for
* a hash key. Please note that calling this method causes the {@link Source#getCode() code} of
* the {@link #getSource() source} to be loaded if it was not yet loaded.
*
* @return first line of the section
* @since 0.8 or earlier
* @deprecated without replacement
*/
@SuppressWarnings("deprecation")
@Deprecated
public LineLocation getLineLocation() {
if (!isValid()) {
return null;
}
return source.createLineLocation(getStartLine());
}
/**
* Returns 1-based line number of the last character in this section (inclusive). Returns
* <code>1</code> for out of bounds or {@link #isAvailable() unavailable} source sections.
* Please note that calling this method causes the {@link Source#getCode() code} of the
* {@link #getSource() source} to be loaded if it was not yet loaded.
*
* @return the starting line number
* @since 0.8 or earlier
*/
public int getEndLine() {
if (source == null) {
return -1;
}
if (!isValid()) {
return 1;
}
return source.getLineNumber(getCharIndex() + Math.max(0, getCharLength() - 1));
}
/**
* Returns the 1-based column number of the last character in this section (inclusive). Returns
* <code>1</code> for out of bounds or {@link #isAvailable() unavailable} source sections.
* Please note that calling this method causes the {@link Source#getCode() code} of the
* {@link #getSource() source} to be loaded if it was not yet loaded.
*
* @return the starting column number
* @since 0.8 or earlier
*/
public int getEndColumn() {
if (source == null) {
return -1;
}
if (!isValid()) {
return 1;
}
return source.getColumnNumber(getCharIndex() + Math.max(0, getCharLength() - 1));
}
/**
* Returns the 0-based index of the first character in this section. Returns <code>0</code> for
* {@link #isAvailable() unavailable} source sections. Please note that calling this method does
* not cause the {@link Source#getCode() code} of the {@link #getSource() source} to be loaded.
* The returned index might be out of bounds of the source code if assertions (-ea) are not
* enabled.
*
* @return the starting character index
* @since 0.8 or earlier
*/
public int getCharIndex() {
return charIndex;
}
/**
* Returns the length of this section in characters. Returns <code>0</code> for
* {@link #isAvailable() unavailable} source sections. Please note that calling this method does
* not cause the {@link Source#getCode() code} of the {@link #getSource() source} to be loaded.
* The returned length might be out of bounds of the source code if assertions (-ea) are not
* enabled.
*
* @return the number of characters in the section
* @since 0.8 or earlier
*/
public int getCharLength() {
if (source == null) {
return -1;
}
return charLength == -1 ? 0 : charLength;
}
/**
* Returns the index of the text position immediately following the last character in the
* section. Returns <code>0</code> for {@link #isAvailable() unavailable} source sections.
* Please note that calling this method does not cause the {@link Source#getCode() code} of the
* {@link #getSource() source} to be loaded. The returned index might be out of bounds of the
* source code if assertions (-ea) are not enabled.
*
* @return the end position of the section
* @since 0.8 or earlier
*/
public int getCharEndIndex() {
if (source == null) {
return -1;
}
return getCharIndex() + getCharLength();
}
/**
* Returns the source code fragment described by this section. Returns an empty string for out
* of bounds or {@link #isAvailable() unavailable} source sections. Please note that calling
* this method causes the {@link Source#getCode() code} of the {@link #getSource() source} to be
* loaded if it was not yet loaded.
*
* @return the code as a string
* @since 0.8 or earlier
* @see Source#getCode(int, int)
*/
public String getCode() {
// TODO remove check for source == null if #createUnavailableSourceSection is removed.
if (source == null) {
return "<unavailable>";
}
if (!isValid()) {
return "";
}
return source.getCode(getCharIndex(), getCharLength());
}
/**
* Returns an implementation-defined string representation of this source section to be used for
* debugging purposes only.
*
* @see #getCode()
* @since 0.8 or earlier
*/
@Override
public String toString() {
StringBuilder b = new StringBuilder();
b.append("SourceSection(source=").append(getSource().getName());
if (isAvailable()) {
b.append(", index=").append(getCharIndex());
b.append(", length=").append(getCharLength());
if (isValid()) {
b.append(", code=").append(getCode().replaceAll("\\n", "\\\\n"));
} else {
b.append(", valid=false");
}
} else {
b.append(" available=false");
}
b.append(")");
return b.toString();
}
/** @since 0.8 or earlier */
@Override
public int hashCode() {
if (!isAvailable()) {
return System.identityHashCode(this);
}
final int prime = 31;
int result = 1;
result = prime * result + charIndex;
result = prime * result + charLength;
result = prime * result + source.hashCode();
return result;
}
/** @since 0.8 or earlier */
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (!(obj instanceof SourceSection)) {
return false;
}
SourceSection other = (SourceSection) obj;
if (!isAvailable()) {
// Unavailable SourceSections are compared by identity
return this == obj;
}
if (charIndex != other.charIndex) {
return false;
}
if (charLength != other.charLength) {
return false;
}
if (source == null) {
if (other.source != null) {
return false;
}
} else if (!source.equals(other.source)) {
return false;
}
return true;
}
}