class Asciidoctor::Reader

Public: Methods for retrieving lines from AsciiDoc source files

Attributes

dir[R]
file[R]
lineno[R]

Public: Get the 1-based offset of the current line.

path[R]
process_lines[RW]

Public: Control whether lines are processed using #process_line on first visit (default: true)

source_lines[R]

Public: Get the document source as a String Array of lines.

Public Class Methods

new(data = nil, cursor = nil) click to toggle source

Public: Initialize the Reader object

# File lib/asciidoctor/reader.rb, line 36
def initialize data = nil, cursor = nil
  if cursor.nil?
    @file = @dir = nil
    @path = '<stdin>'
    @lineno = 1 # IMPORTANT lineno assignment must proceed prepare_lines call!
  elsif cursor.is_a? String
    @file = cursor
    @dir = File.dirname @file
    @path = File.basename @file
    @lineno = 1 # IMPORTANT lineno assignment must proceed prepare_lines call!
  else
    @file = cursor.file
    @dir = cursor.dir
    @path = cursor.path || '<stdin>'
    unless @file.nil?
      if @dir.nil?
        # REVIEW might to look at this assignment closer
        @dir = File.dirname @file
        @dir = nil if @dir == '.' # right?
      end

      if cursor.path.nil?
        @path = File.basename @file
      end
    end
    @lineno = cursor.lineno || 1 # IMPORTANT lineno assignment must proceed prepare_lines call!
  end
  @lines = data.nil? ? [] : (prepare_lines data)
  @source_lines = @lines.dup
  @eof = @lines.empty?
  @look_ahead = 0
  @process_lines = true
  @unescape_next_line = false
end

Public Instance Methods

advance(direct = true) click to toggle source

Public: Advance to the next line by discarding the line at the front of the stack

direct - A Boolean flag to bypasses the check for more lines and immediately

returns the first element of the internal @lines Array. (default: true)

returns a Boolean indicating whether there was a line to discard.

# File lib/asciidoctor/reader.rb, line 237
def advance direct = true
  !(read_line direct).nil?
end
cursor() click to toggle source
# File lib/asciidoctor/reader.rb, line 489
def cursor
  Cursor.new @file, @dir, @path, @lineno
end
empty?()
Alias for: eof?
eof?() click to toggle source

Public: Check whether this reader is empty (contains no lines)

Returns true if there are no more lines to peek, otherwise false.

# File lib/asciidoctor/reader.rb, line 377
def eof?
  !has_more_lines?
end
Also aliased as: empty?
has_more_lines?() click to toggle source

Public: Check whether there are any lines left to read.

If a previous call to this method resulted in a value of false, immediately returned the cached value. Otherwise, delegate to #peek_line to determine if there is a next line available.

Returns True if there are more lines, False if there are not.

# File lib/asciidoctor/reader.rb, line 111
def has_more_lines?
  !(@eof || (@eof = peek_line.nil?))
end
line_info() click to toggle source

Public: Get information about the last line read, including file name and line number.

Returns A String summary of the last line read

# File lib/asciidoctor/reader.rb, line 496
def line_info
  %Q(#{@path}: line #{@lineno})
end
Also aliased as: next_line_info
lines() click to toggle source

Public: Get a copy of the remaining Array of String lines managed by this Reader

Returns A copy of the String Array of lines remaining in this Reader

# File lib/asciidoctor/reader.rb, line 508
def lines
  @lines.dup
end
next_line_empty?() click to toggle source

Public: Peek at the next line and check if it's empty (i.e., whitespace only)

This method Does not consume the line from the stack.

Returns True if the there are no more lines or if the next line is empty

# File lib/asciidoctor/reader.rb, line 120
def next_line_empty?
  (line = peek_line).nil? || line.chomp.empty?
end
next_line_info()
Alias for: line_info
peek_line(direct = false) click to toggle source

Public: Peek at the next line of source data. Processes the line, if not already marked as processed, but does not consume it.

This method will probe the reader for more lines. If there is a next line that has not previously been visited, the line is passed to the Reader#preprocess_line method to be initialized. This call gives sub-classess the opportunity to do preprocessing. If the return value of the #process_line is nil, the data is assumed to be changed and #peek_line is invoked again to perform further processing.

direct - A Boolean flag to bypasses the check for more lines and immediately

returns the first element of the internal @lines Array. (default: false)

Returns the next line of the source data as a String if there are lines remaining. Returns nil if there is no more data.

# File lib/asciidoctor/reader.rb, line 139
def peek_line direct = false
  if direct || @look_ahead > 0
    @unescape_next_line ? @lines.first[1..-1] : @lines.first
  elsif @eof || @lines.empty?
    @eof = true
    @look_ahead = 0
    nil
  else
    # FIXME the problem with this approach is that we aren't
    # retaining the modified line (hence the @unescape_next_line tweak)
    # perhaps we need a stack of proxy lines
    if (line = process_line @lines.first).nil?
      peek_line
    else
      line
    end
  end
end
peek_lines(num = 1, direct = true) click to toggle source

Public: Peek at the next multiple lines of source data. Processes the lines, if not already marked as processed, but does not consume them.

This method delegates to #read_line to process and collect the line, then restores the lines to the stack before returning them. This allows the lines to be processed and marked as such so that subsequent reads will not need to process the lines again.

num - The Integer number of lines to peek. direct - A Boolean indicating whether processing should be disabled when reading lines

Returns A String Array of the next multiple lines of source data, or an empty Array if there are no more lines in this Reader.

# File lib/asciidoctor/reader.rb, line 171
def peek_lines num = 1, direct = true
  old_look_ahead = @look_ahead
  result = []
  (1..num).each do
    if (line = read_line direct)
      result << line
    else
      break
    end
  end

  unless result.empty?
    result.reverse_each {|line| unshift line }
    @look_ahead = old_look_ahead if direct
  end

  result
end
prepare_lines(data, opts = {}) click to toggle source

Internal: Prepare the lines from the provided data

This method strips whitespace from the end of every line of the source data and appends a LF (i.e., Unix endline). This whitespace substitution is very important to how Asciidoctor works.

Any leading or trailing blank lines are also removed.

The normalized lines are assigned to the @lines instance variable.

data - A String Array of input data to be normalized opts - A Hash of options to control what cleansing is done

Returns The String lines extracted from the data

# File lib/asciidoctor/reader.rb, line 86
def prepare_lines data, opts = {}
  data.is_a?(String) ? data.each_line.to_a : data.dup
end
prev_line_info() click to toggle source
# File lib/asciidoctor/reader.rb, line 501
def prev_line_info
  %Q(#{@path}: line #{@lineno - 1})
end
process_line(line) click to toggle source

Internal: Processes a previously unvisited line

By default, this method marks the line as processed by incrementing the look_ahead counter and returns the line unmodified.

Returns The String line the Reader should make available to the next invocation of #read_line or nil if the Reader should drop the line, advance to the next line and process it.

# File lib/asciidoctor/reader.rb, line 99
def process_line line
  @look_ahead += 1 if @process_lines
  line
end
read() click to toggle source

Public: Get the remaining lines of source data joined as a String.

Delegates to #read_lines, then joins the result.

Returns the lines read joined as a String

# File lib/asciidoctor/reader.rb, line 227
def read
  read_lines.join
end
read_line(direct = false) click to toggle source

Public: Get the next line of source data. Consumes the line returned.

direct - A Boolean flag to bypasses the check for more lines and immediately

returns the first element of the internal @lines Array. (default: false)

Returns the String of the next line of the source data if data is present. Returns nil if there is no more data.

# File lib/asciidoctor/reader.rb, line 197
def read_line direct = false
  if direct || @look_ahead > 0 || has_more_lines?
    shift
  else
    nil
  end
end
read_lines() click to toggle source

Public: Get the remaining lines of source data.

This method calls #read_line repeatedly until all lines are consumed and returns the lines as a String Array. This method differs from #lines in that it processes each line in turn, hence triggering any preprocessors implemented in sub-classes.

Returns the lines read as a String Array

# File lib/asciidoctor/reader.rb, line 213
def read_lines
  lines = []
  while has_more_lines?
    lines << read_line
  end
  lines
end
Also aliased as: readlines
read_lines_until(options = {}) { |line)| ... } click to toggle source

Public: Return all the lines from `@lines` until we (1) run out them,

(2) find a blank line with :break_on_blank_lines => true, or (3) find
a line for which the given block evals to true.

options - an optional Hash of processing options:

* :break_on_blank_lines may be used to specify to break on
    blank lines
* :skip_first_line may be used to tell the reader to advance
    beyond the first line before beginning the scan
* :preserve_last_line may be used to specify that the String
    causing the method to stop processing lines should be
    pushed back onto the `lines` Array.
* :read_last_line may be used to specify that the String
    causing the method to stop processing lines should be
    included in the lines being returned

Returns the Array of lines forming the next segment.

Examples

reader = Reader.new ["First paragraph\n", "Second paragraph\n",
                     "Open block\n", "\n", "Can have blank lines\n",
                     "--\n", "\n", "In a different segment\n"]

reader.read_lines_until
=> ["First paragraph\n", "Second paragraph\n", "Open block\n"]
# File lib/asciidoctor/reader.rb, line 408
def read_lines_until options = {}
  result = []
  advance if options[:skip_first_line]
  if @process_lines && options[:skip_processing]
    @process_lines = false
    restore_process_lines = true
  else
    restore_process_lines = false
  end

  has_block = block_given?
  if (terminator = options[:terminator])
    break_on_blank_lines = false
    break_on_list_continuation = false
    chomp_last_line = options.fetch :chomp_last_line, false
  else
    break_on_blank_lines = options[:break_on_blank_lines]
    break_on_list_continuation = options[:break_on_list_continuation]
    chomp_last_line = break_on_blank_lines
  end
  skip_line_comments = options[:skip_line_comments]
  line_read = false
  line_restored = false
  
  while (line = read_line)
    finish = while true
      break true if terminator && line.chomp == terminator
      # QUESTION: can we get away with line.chomp.empty? here?
      break true if break_on_blank_lines && line.chomp.empty?
      if break_on_list_continuation && line_read && line.chomp == LIST_CONTINUATION
        options[:preserve_last_line] = true
        break true
      end
      break true if has_block && (yield line)
      break false
    end

    if finish
      if options[:read_last_line]
        result << line
        line_read = true
      end
      if options[:preserve_last_line]
        restore_line line
        line_restored = true
      end
      break
    end

    unless skip_line_comments && line.start_with?('//') && line.match(REGEXP[:comment])
      result << line
      line_read = true
    end
  end

  if chomp_last_line && line_read
    result << result.pop.chomp
  end

  if restore_process_lines
    @process_lines = true
    @look_ahead -= 1 if line_restored && terminator.nil?
  end
  result
end
readlines()
Alias for: read_lines
replace_line(replacement) click to toggle source

Public: Replace the current line with the specified line.

Calls #advance to consume the current line, then calls #unshift to push the replacement onto the top of the line stack.

replacement - The String line to put in place of the line at the cursor.

Returns nothing.

# File lib/asciidoctor/reader.rb, line 275
def replace_line replacement
  advance
  unshift replacement
  nil
end
restore_line(line_to_restore)
Alias for: unshift_line
restore_lines(lines_to_restore)
Alias for: unshift_lines
shift() click to toggle source

Internal: Shift the line off the stack and increment the lineno

# File lib/asciidoctor/reader.rb, line 475
def shift
  @lineno += 1
  @look_ahead -= 1 unless @look_ahead == 0
  @lines.shift
end
skip_blank_lines() click to toggle source

Public: Strip off leading blank lines in the Array of lines.

Examples

@lines
=> ["\n", "\t\n", "Foo\n", "Bar\n", "\n"]

skip_blank_lines
=> 2

@lines
=> ["Foo\n", "Bar\n"]

Returns an Integer of the number of lines skipped

# File lib/asciidoctor/reader.rb, line 295
def skip_blank_lines
  return 0 if eof?

  num_skipped = 0
  # optimized code for shortest execution path
  while (next_line = peek_line)
    if next_line.chomp.empty?
      advance
      num_skipped += 1
    else
      return num_skipped
    end
  end

  num_skipped
end
skip_comment_lines(opts = {}) click to toggle source

Public: Skip consecutive lines containing line comments and return them.

Examples

@lines
=> ["// foo\n", "bar\n"]

comment_lines = skip_comment_lines
=> ["// foo\n"]

@lines
=> ["bar\n"]

Returns the Array of lines that were skipped

# File lib/asciidoctor/reader.rb, line 325
def skip_comment_lines opts = {}
  return [] if eof?

  comment_lines = []
  include_blank_lines = opts[:include_blank_lines]
  while (next_line = peek_line)
    if include_blank_lines && next_line.chomp.empty?
      comment_lines << read_line
    elsif (commentish = next_line.start_with?('//')) && (match = next_line.match(REGEXP[:comment_blk]))
      comment_lines << read_line
      comment_lines.push(*(read_lines_until(:terminator => match[0], :read_last_line => true, :skip_processing => true)))
    elsif commentish && next_line.match(REGEXP[:comment])
      comment_lines << read_line
    else
      break
    end
  end

  comment_lines
end
skip_line_comments() click to toggle source

Public: Skip consecutive lines that are line comments and return them.

# File lib/asciidoctor/reader.rb, line 347
def skip_line_comments
  return [] if eof?

  comment_lines = []
  # optimized code for shortest execution path
  while (next_line = peek_line)
    if next_line.match(REGEXP[:comment])
      comment_lines << read_line
    else
      break
    end
  end

  comment_lines
end
source() click to toggle source

Public: Get the source lines for this Reader joined as a String

# File lib/asciidoctor/reader.rb, line 518
def source
  @source_lines.join
end
string() click to toggle source

Public: Get a copy of the remaining lines managed by this Reader joined as a String

# File lib/asciidoctor/reader.rb, line 513
def string
  @lines.join
end
terminate() click to toggle source

Public: Advance to the end of the reader, consuming all remaining lines

Returns nothing.

# File lib/asciidoctor/reader.rb, line 366
def terminate
  @lineno += @lines.size
  @lines.clear
  @eof = true
  @look_ahead = 0
  nil
end
to_s() click to toggle source

Public: Get a summary of this Reader.

Returns A string summary of this reader, which contains the path and line information

# File lib/asciidoctor/reader.rb, line 526
def to_s
  line_info
end
unshift(line) click to toggle source

Internal: Restore the line to the stack and decrement the lineno

# File lib/asciidoctor/reader.rb, line 482
def unshift line
  @lineno -= 1
  @look_ahead += 1
  @eof = false
  @lines.unshift line
end
unshift_line(line_to_restore) click to toggle source

Public: Push the String line onto the beginning of the Array of source data.

Since this line was (assumed to be) previously retrieved through the reader, it is marked as seen.

returns nil

# File lib/asciidoctor/reader.rb, line 247
def unshift_line line_to_restore
  unshift line_to_restore
  nil
end
Also aliased as: restore_line
unshift_lines(lines_to_restore) click to toggle source

Public: Push an Array of lines onto the front of the Array of source data.

Since these lines were (assumed to be) previously retrieved through the reader, they are marked as seen.

Returns nil

# File lib/asciidoctor/reader.rb, line 259
def unshift_lines lines_to_restore
  # QUESTION is it faster to use unshift(*lines_to_restore)?
  lines_to_restore.reverse_each {|line| unshift line }
  nil
end
Also aliased as: restore_lines