IndentDedentInputBuffer (parboiled-project 1.0.2 API)

java.lang.Object
- org.parboiled.buffers.IndentDedentInputBuffer

All Implemented Interfaces:

InputBuffer
```
public class IndentDedentInputBuffer
extends Object
implements InputBuffer
```
Special, immutable InputBuffer implementation for indentation based grammars.
This InputBuffer collapses all space and tab characters at the beginning of a text line into either nothing (if the line has the same indentation level as the previous line), a special Chars.INDENT character (if the line has a greater indentation level than the previous line) or one or more Chars.DEDENT characters (if the line has a lower indentation level than the previous line).

Blank lines (lines containing nothing but whitespace) are removed from the input and the buffer can, optionally, remove line comments (i.e. comments that start with a predefined character sequence and go to the end of the line).

This means that the highest index of this InputBuffer is probably smaller than that of the original input text buffer, since all line indentations and blank lines have been collapsed. However, the implementation will make sure that getPosition(int), extract(int, int), etc. will work as expected and always return the "correct" result from the underlying, original input buffer.

If the input contains illegal indentation the buffer throws an IllegalIndentationException during construction

Constructor Summary

Constructors
Constructor and Description
`IndentDedentInputBuffer(char[] input, int tabStop, String lineCommentStart, boolean strict)` Creates a new IndentDedentInputBuffer around the given char array.

Method Summary

Methods
Modifier and Type	Method and Description
`char`	`charAt(int index)` Returns the character at the given index.
`String`	`extract(IndexRange range)` Constructs a new `String` from all character covered by the given IndexRange.
`String`	`extract(int start, int end)` Constructs a new `String` from all character between the given indices.
`String`	`extractLine(int lineNumber)` Constructs a new `String` containing all characters with the given line number except for the trailing newline.
`int`	`getLineCount()` Returns the number of lines in the input buffer.
`int`	`getOriginalIndex(int index)` Translates the given index from the scope of this InputBuffer to the scope of the original, underlying char array.
`Position`	`getPosition(int index)` Returns the line and column number of the character with the given index encapsulated in a `Position` object.
`boolean`	`test(int index, char[] characters)` Determines whether the characters starting at the given index match the ones from the given array (in order).

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - IndentDedentInputBuffer
```
public IndentDedentInputBuffer(char[] input,
                       int tabStop,
                       String lineCommentStart,
                       boolean strict)
```
    Creates a new IndentDedentInputBuffer around the given char array. Note that for performance reasons the given char array is not defensively copied.
    
    Parameters:
    input - the input text.
    tabStop - the number of characters in a tab stop.
    lineCommentStart - the string starting a line comment or null, if line comments are not defined
    strict - signals whether the buffer should throw an IllegalIndentationException on "semi-dedents", if false the buffer silently accepts these
    
    Throws:
    
    IllegalIndentationException - if the input contains illegal indentations and the strict flag is set
- Method Detail
  - charAt
```
public char charAt(int index)
```
    Description copied from interface: InputBuffer
    
    Returns the character at the given index. If the index is invalid the method returns Chars.EOI.
    
    Specified by:
    
    charAt in interface InputBuffer
    
    Parameters:
    index - the index
    
    Returns:
    the character at the given index or Chars.EOI.
  - test
```
public boolean test(int index,
           char[] characters)
```
    Description copied from interface: InputBuffer
    
    Determines whether the characters starting at the given index match the ones from the given array (in order).
    
    Specified by:
    
    test in interface InputBuffer
    
    Parameters:
    index - the index into the input buffer where to start the comparison
    characters - the characters to test against the input buffer
    
    Returns:
    true if matched
  - extract
```
public String extract(int start,
             int end)
```
    Description copied from interface: InputBuffer
    
    Constructs a new String from all character between the given indices. Invalid indices are automatically adjusted to their respective boundary.
    
    Specified by:
    
    extract in interface InputBuffer
    
    Parameters:
    start - the start index (inclusively)
    end - the end index (exclusively)
    
    Returns:
    a new String (non-interned)
  - extract
```
public String extract(IndexRange range)
```
    Description copied from interface: InputBuffer
    
    Constructs a new String from all character covered by the given IndexRange.
    
    Specified by:
    
    extract in interface InputBuffer
    
    Parameters:
    range - the IndexRange
    
    Returns:
    a new String (non-interned)
  - getPosition
```
public Position getPosition(int index)
```
    Description copied from interface: InputBuffer
    
    Returns the line and column number of the character with the given index encapsulated in a Position object. The very first character has the line number 1 and the column number 1.
    
    Specified by:
    
    getPosition in interface InputBuffer
    
    Parameters:
    index - the index of the character to get the line number of
    
    Returns:
    the line number
  - getOriginalIndex
```
public int getOriginalIndex(int index)
```
    Description copied from interface: InputBuffer
    
    Translates the given index from the scope of this InputBuffer to the scope of the original, underlying char array. The DefaultInputBuffer implementation simply returns the given index, but other implementations like the IndentDedentInputBuffer or the MutableInputBuffer need to "undo" all compressions and index shiftings performed internally in order to return the underlying index.
    
    Specified by:
    
    getOriginalIndex in interface InputBuffer
    
    Parameters:
    index - the index relative to this InputBuffer
    
    Returns:
    the index relative to the underlying string or char array
  - extractLine
```
public String extractLine(int lineNumber)
```
    Description copied from interface: InputBuffer
    
    Constructs a new String containing all characters with the given line number except for the trailing newline.
    
    Specified by:
    
    extractLine in interface InputBuffer
    
    Parameters:
    lineNumber - the line number to get
    
    Returns:
    the string
  - getLineCount
```
public int getLineCount()
```
    Description copied from interface: InputBuffer
    
    Returns the number of lines in the input buffer.
    
    Specified by:
    
    getLineCount in interface InputBuffer
    
    Returns:
    number of lines in the input buffer.

Class IndentDedentInputBuffer

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

IndentDedentInputBuffer

Method Detail

charAt

test

extract

extract

getPosition

getOriginalIndex

extractLine

getLineCount