Module org.eclipse.xtext.xbase.lib
Package org.eclipse.xtend2.lib

Class StringConcatenation

java.lang.Object
org.eclipse.xtend2.lib.StringConcatenation
All Implemented Interfaces:
CharSequence
@GwtCompatible public class StringConcatenation extends Object implements CharSequence

A StringConcatenation allows for efficient, indentation aware concatenation of character sequences.

In addition to the methods that are specified by the implemented interface CharSequence, there are some other public operations that allow to modify the contents of this sequence. The string representation of arbitrary objects can be appended to an instance of StringConcatenation. There are overloaded variants of append(Object, String) that allow to pass an indentation that should be applied to each line of the appended content. Each line break that is part of the new content will be replaced by the line delimiter that was configured for this StringConcatenation.

The append-operation ignores null arguments. This is different to what StringBuffer or StringBuilder do and that's the reason why the Appendable interface is not fulfilled by a StringConcatenation.

The object uses an internal List of Strings that is concatenated on demand to a complete sequence. Use toString() to get the joined version of a StringConcatenation.

Object.equals(Object) and Object.hashCode() are not specialized for a StringConcatenation, that is, the semantics are based on identity similar to what StringBuffer and StringBuilder do.

Since:
2.3
Author:
Sebastian Zarnekow - Initial contribution and API

  • Field Details

    • DEFAULT_LINE_DELIMITER

      public static final String DEFAULT_LINE_DELIMITER
      The default line delimiter that is used by instances of StringConcatenation. It uses System.getProperty("line.separator").
      Since:
      2.3

  • Constructor Details

    • StringConcatenation

      public StringConcatenation()
      Create a new concatenation that uses the system line delimiter.
      See Also:

    • StringConcatenation

      public StringConcatenation(String lineDelimiter)
      Create a new concatenation with the specified delimiter.
      Parameters:
      lineDelimiter - the used delimiter.
      Throws:
      IllegalArgumentException - if the lineDelimiter is null or the empty String.
      Since:
      2.3

  • Method Details

    • append

      public void append(Object object)
      Append the string representation of the given object to this sequence. Does nothing if the object is null.
      Parameters:
      object - the to-be-appended object.

    • append

      public void append(String str)
      Append the given string to this sequence. Does nothing if the string is null.
      Parameters:
      str - the to-be-appended string.
      Since:
      2.11

    • append

      public void append(StringConcatenation concat)
      Append the contents of a given StringConcatenation to this sequence. Does nothing if the concatenation is null.
      Parameters:
      concat - the to-be-appended StringConcatenation.
      Since:
      2.11

    • append

      public void append(StringConcatenationClient client)
      Append the contents of a given StringConcatenationClient to this sequence. Does nothing if the argument is null.
      Parameters:
      client - the to-be-appended StringConcatenationClient.
      Since:
      2.11

    • append

      protected void append(Object object, int index)

    • append

      public void append(Object object, String indentation)
      Add the string representation of the given object to this sequence. The given indentation will be prepended to each line except the first one if the object has a multi-line string representation.
      Parameters:
      object - the appended object.
      indentation - the indentation string that should be prepended. May not be null.

    • append

      public void append(String str, String indentation)
      Add the given string to this sequence. The given indentation will be prepended to each line except the first one if the object has a multi-line string representation.
      Parameters:
      str - the appended string.
      indentation - the indentation string that should be prepended. May not be null.
      Since:
      2.11

    • append

      public void append(StringConcatenation concat, String indentation)
      Append the contents of a given StringConcatenation to this sequence. Does nothing if the concatenation is null. The given indentation will be prepended to each line except the first one.
      Parameters:
      concat - the to-be-appended StringConcatenation.
      indentation - the indentation string that should be prepended. May not be null.
      Since:
      2.11

    • append

      public void append(StringConcatenationClient client, String indentation)
      Append the contents of a given StringConcatenationClient to this sequence. Does nothing if that argument is null. The given indentation will be prepended to each line except the first one.
      Parameters:
      client - the to-be-appended StringConcatenationClient.
      indentation - the indentation string that should be prepended. May not be null.
      Since:
      2.11

    • append

      protected void append(Object object, String indentation, int index)
      Add the string representation of the given object to this sequence at the given index. The given indentation will be prepended to each line except the first one if the object has a multi-line string representation.
      Parameters:
      object - the to-be-appended object.
      indentation - the indentation string that should be prepended. May not be null.
      index - the index in the list of segments.

    • getStringRepresentation

      protected String getStringRepresentation(Object object)
      Computes the string representation of the given object. The default implementation will just invoke Object.toString() but clients may override and specialize the logic.
      Parameters:
      object - the object that shall be appended. Never null.
      Returns:
      the string representation. May not be null.
      Since:
      2.5

    • appendImmediate

      public void appendImmediate(Object object, String indentation)
      Add the string representation of the given object to this sequence immediately. That is, all the trailing whitespace of this sequence will be ignored and the string is appended directly after the last segment that contains something besides whitespace. The given indentation will be prepended to each line except the first one if the object has a multi-line string representation.
      Parameters:
      object - the to-be-appended object.
      indentation - the indentation string that should be prepended. May not be null.

    • appendSegments

      protected void appendSegments(String indentation, int index, List<String> otherSegments, String otherDelimiter)
      Add the list of segments to this sequence at the given index. The given indentation will be prepended to each line except the first one if the object has a multi-line string representation.
      Parameters:
      indentation - the indentation string that should be prepended. May not be null.
      index - the index in this instance's list of segments.
      otherSegments - the to-be-appended segments. May not be null.
      otherDelimiter - the line delimiter that was used in the otherSegments list.

    • appendSegments

      protected void appendSegments(int index, List<String> otherSegments, String otherDelimiter)
      Add the list of segments to this sequence at the given index. The given indentation will be prepended to each line except the first one if the object has a multi-line string representation.
      Parameters:
      index - the index in this instance's list of segments.
      otherSegments - the to-be-appended segments. May not be null.
      otherDelimiter - the line delimiter that was used in the otherSegments list.
      Since:
      2.5

    • appendSegments

      protected void appendSegments(int index, List<String> otherSegments)
      Add the list of segments to this sequence at the given index. The given indentation will be prepended to each line except the first one if the object has a multi-line string representation.
      Parameters:
      index - the index in this instance's list of segments.
      otherSegments - the to-be-appended segments. May not be null.
      Since:
      2.5

    • newLine

      public void newLine()
      Add a newline to this sequence according to the configured lineDelimiter.

    • newLineIfNotEmpty

      public void newLineIfNotEmpty()
      Add a newline to this sequence according to the configured lineDelimiter if the last line contains something besides whitespace.

    • toString

      public String toString()
      Specified by:
      toString in interface CharSequence
      Overrides:
      toString in class Object

    • getContent

      protected final List<String> getContent()
      Return the actual content of this sequence, including all trailing whitespace. The return value is unsafe, that is modification to this StringConcatenation will cause changes in a previously obtained result and vice versa.
      Returns:
      the actual content of this instance. Never null.
      Since:
      2.8

    • getSignificantContent

      protected List<String> getSignificantContent()
      Compute the significant content of this sequence. That is, trailing whitespace after the last line-break will be ignored if the last line contains only whitespace. The return value is unsafe, that is modification to this StringConcatenation will cause changes in a previously obtained result and vice versa.
      Returns:
      the significant content of this instance. Never null.

    • getLineDelimiter

      protected String getLineDelimiter()
      Allows subtypes to access the configured line delimiter.
      Returns:
      the line delimiter
      Since:
      2.5

    • length

      public int length()

      Only the significant content of this sequence is considered.

      Specified by:
      length in interface CharSequence

    • charAt

      public char charAt(int index)

      Only the significant content of this sequence is considered.

      Specified by:
      charAt in interface CharSequence

    • subSequence

      public CharSequence subSequence(int start, int end)

      Only the significant content of this sequence is considered.

      Specified by:
      subSequence in interface CharSequence

    • splitLinesAndNewLines

      protected List<String> splitLinesAndNewLines(String text)
      Return a list of segments where each segment is either the content of a line in the given text or a line-break according to the configured delimiter. Existing line-breaks in the text will be replaced by this's instances delimiter.
      Parameters:
      text - the to-be-splitted text. May be null.
      Returns:
      a list of segments. Is never null.