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package com.oracle.truffle.api.source;


Description of contiguous section of text within a Source of program code.; supports multiple modes of access to the text and its location. 
 Two available source sections are considered equal if their sources, start and length are equal. Unavailable source sections are compared by identity. Source sections can be used as keys in hash maps. 
See Also:
Since:0.8 or earlier
/**
 * 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#createSection(int, int, int, int)
 * @see Source#createUnavailableSection()
 * @since 0.8 or earlier
 */
public abstract class SourceSection {

    final Source source;

    SourceSection(Source source) {
        assert source != null;
        this.source = source;
    }

    
Returns whether this is a special instance that signifies that source information is available. Unavailable source sections can be created using 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 0.

See Also:
Since:0.18
/**
     * 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 abstract boolean isAvailable();

    
Returns whether the source section is in bounds of the source code. 
/**
     * Returns whether the source section is in bounds of the {@link #getSource() source}
     * {@link Source#getCharacters() code}.
     */
    abstract boolean isValid();

    
Returns true if this section has a line number information, false
otherwise. When true, getStartLine() and getEndLine() return valid line numbers, when false, getStartLine() and getEndLine() return 1.

Since:19.0
/**
     * Returns <code>true</code> if this section has a line number information, <code>false</code>
     * otherwise. When <code>true</code>, {@link #getStartLine()} and {@link #getEndLine()} return
     * valid line numbers, when <code>false</code>, {@link #getStartLine()} and
     * {@link #getEndLine()} return <code>1</code>.
     *
     * @since 19.0
     */
    public abstract boolean hasLines();

    
Returns true if this section has a column number information, false
otherwise. When true, hasLines() is true as well, getStartColumn() and getEndColumn() return valid column numbers. When false, getStartColumn() and getEndColumn() return 1.

Since:19.0
/**
     * Returns <code>true</code> if this section has a column number information, <code>false</code>
     * otherwise. When <code>true</code>, {@link #hasLines()} is <code>true</code> as well,
     * {@link #getStartColumn()} and {@link #getEndColumn()} return valid column numbers. When
     * <code>false</code>, {@link #getStartColumn()} and {@link #getEndColumn()} return
     * <code>1</code>.
     *
     * @since 19.0
     */
    public abstract boolean hasColumns();

    
Returns true if this section has a character index information,
false otherwise. When true, getCharIndex(), getCharEndIndex() and getCharLength() return valid character indices, when false, getCharIndex(), getCharEndIndex() and getCharLength() return 0.

Since:19.0
/**
     * Returns <code>true</code> if this section has a character index information,
     * <code>false</code> otherwise. When <code>true</code>, {@link #getCharIndex()},
     * {@link #getCharEndIndex()} and {@link #getCharLength()} return valid character indices, when
     * <code>false</code>, {@link #getCharIndex()}, {@link #getCharEndIndex()} and
     * {@link #getCharLength()} return <code>0</code>.
     *
     * @since 19.0
     */
    public abstract boolean hasCharIndex();

    
Representation of the source program that contains this section.

Returns:the source object
Since:0.8 or earlier
/**
     * Representation of the source program that contains this section.
     *
     * @return the source object
     * @since 0.8 or earlier
     */
    public final Source getSource() {
        return source;
    }

    
Returns 1-based line number of the first character in this section (inclusive). Returns
1 for out of bounds or unavailable source sections, or source sections not having lines. 
See Also:
Returns:the starting line number
Since:0.8 or earlier
/**
     * 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, or
     * source sections not {@link #hasLines() having lines}.
     *
     * @return the starting line number
     * @see #hasLines()
     * @since 0.8 or earlier
     */
    public abstract int getStartLine();

    
Returns the 1-based column number of the first character in this section (inclusive). Returns
1 for out of bounds or unavailable source sections, or source sections not having columns. 
See Also:
Returns:the starting column number
Since:0.8 or earlier
/**
     * 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, or
     * source sections not {@link #hasColumns() having columns}.
     *
     * @return the starting column number
     * @see #hasColumns()
     * @since 0.8 or earlier
     */
    public abstract int getStartColumn();

    
Returns 1-based line number of the last character in this section (inclusive). Returns
1 for out of bounds or unavailable source sections, or source sections not having lines. 
See Also:
Returns:the starting line number
Since:0.8 or earlier
/**
     * 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, or
     * source sections not {@link #hasLines() having lines}.
     *
     * @return the starting line number
     * @see #hasLines()
     * @since 0.8 or earlier
     */
    public abstract int getEndLine();

    
Returns the 1-based column number of the last character in this section (inclusive). Returns
1 for out of bounds or unavailable source sections, or source sections not having columns. 
See Also:
Returns:the starting column number
Since:0.8 or earlier
/**
     * 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, or
     * source sections not {@link #hasColumns() having columns}.
     *
     * @return the starting column number
     * @see #hasColumns()
     * @since 0.8 or earlier
     */
    public abstract int getEndColumn();

    
Returns the 0-based index of the first character in this section. Returns 0 for unavailable source sections, or sections not 
having character index. The returned index might be out of bounds of the source code if assertions (-ea) are not enabled. 
See Also:
Returns:the starting character index
Since:0.8 or earlier
/**
     * Returns the 0-based index of the first character in this section. Returns <code>0</code> for
     * {@link #isAvailable() unavailable} source sections, or sections not {@link #hasCharIndex()
     * having character index}. The returned index might be out of bounds of the source code if
     * assertions (-ea) are not enabled.
     *
     * @return the starting character index
     * @see #hasCharIndex()
     * @since 0.8 or earlier
     */
    public abstract int getCharIndex();

    
Returns the length of this section in characters. Returns 0 for unavailable source sections, or sections not 
having character index. The returned length might be out of bounds of the source code if assertions (-ea) are not enabled. 
See Also:
Returns:the number of characters in the section
Since:0.8 or earlier
/**
     * Returns the length of this section in characters. Returns <code>0</code> for
     * {@link #isAvailable() unavailable} source sections, or sections not {@link #hasCharIndex()
     * having character index}. 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
     * @see #hasCharIndex()
     * @since 0.8 or earlier
     */
    public abstract int getCharLength();

    
Returns the index of the text position immediately following the last character in the
section. Returns 0 for unavailable source sections, or sections not having character index. The returned index might be out of bounds of the source code if assertions (-ea) are not enabled. 
See Also:
Returns:the end position of the section
Since:0.8 or earlier
/**
     * 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, or
     * sections not {@link #hasCharIndex() having character index}. 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
     * @see #hasCharIndex()
     * @since 0.8 or earlier
     */
    public abstract int getCharEndIndex();

    
Returns the source code fragment described by this section. Returns an empty character sequence for out of bounds or unavailable source sections, or sections whose source does not have characters. 
See Also:
Returns:the code as a CharSequence
Since:0.28
/**
     * Returns the source code fragment described by this section. Returns an empty character
     * sequence for out of bounds or {@link #isAvailable() unavailable} source sections, or sections
     * whose source does not {@link Source#hasCharacters() have characters}.
     *
     * @return the code as a CharSequence
     * @see Source#hasCharacters()
     * @since 0.28
     */
    public abstract CharSequence getCharacters();

    
Returns an implementation-defined string representation of this source section to be used for
debugging purposes only.

See Also:
  • getCharacters()
Since:0.8 or earlier
/**
     * Returns an implementation-defined string representation of this source section to be used for
     * debugging purposes only.
     *
     * @see #getCharacters()
     * @since 0.8 or earlier
     */
    @Override
    public final String toString() {
        StringBuilder b = new StringBuilder();
        b.append("SourceSection(source=").append(getSource().getName());
        if (isAvailable()) {
            if (hasLines()) {
                b.append(" [").append(getStartLine());
                if (hasColumns()) {
                    b.append(':').append(getStartColumn());
                }
                b.append(" - ").append(getEndLine());
                if (hasColumns()) {
                    b.append(':').append(getEndColumn());
                }
                b.append("]");
            }
            if (hasCharIndex()) {
                b.append(", index=").append(getCharIndex());
                b.append(", length=").append(getCharLength());
            }
            if (isValid()) {
                if (source.hasCharacters()) {
                    b.append(", characters=").append(getCharacters().toString().replaceAll("\\n", "\\\\n"));
                } else {
                    b.append(", characters not known");
                }
            } else {
                b.append(", valid=false");
            }
        } else {
            b.append(" available=false");
        }
        b.append(")");
        return b.toString();
    }

    
Since:0.8 or earlier
/** @since 0.8 or earlier */
    @Override
    public abstract int hashCode();

    
Since:0.8 or earlier
/** @since 0.8 or earlier */
    @Override
    public abstract boolean equals(Object obj);

}