Class: REXML::Source

Inherits:
Object show all
Includes:
Encoding
Defined in:
lib/rexml/source.rb

Overview

A Source can be searched for patterns, and wraps buffers and other objects and provides consumption of text

Direct Known Subclasses

IOSource

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Encoding

#decode, #encode

Constructor Details

#initialize(arg, encoding = nil) ⇒ Source

Constructor value, overriding all encoding detection

Parameters:

  • arg —

    must be a String, and should be a valid XML document

  • encoding (defaults to: nil) —

    if non-null, sets the encoding of the source to this



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# File 'lib/rexml/source.rb', line 43

def initialize(arg, encoding=nil)
  @orig = @buffer = arg
  if encoding
    self.encoding = encoding
  else
    detect_encoding
  end
  @line = 0
end

Instance Attribute Details

#buffer ⇒ Object (readonly)

The current buffer (what we’re going to read next)



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# File 'lib/rexml/source.rb', line 34

def buffer
  @buffer
end

#encoding ⇒ Object

Returns the value of attribute encoding



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# File 'lib/rexml/source.rb', line 37

def encoding
  @encoding
end

#line ⇒ Object (readonly)

The line number of the last consumed text



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# File 'lib/rexml/source.rb', line 36

def line
  @line
end

Instance Method Details

#consume(pattern) ⇒ Object 



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# File 'lib/rexml/source.rb', line 87

def consume( pattern )
  @buffer = $' if pattern.match( @buffer )
end

#current_line ⇒ Object

Returns the current line in the source.

Returns:

  • the current line in the source



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# File 'lib/rexml/source.rb', line 117

def current_line
  lines = @orig.split
  res = lines.grep @buffer[0..30]
  res = res[-1] if res.kind_of? Array
  lines.index( res ) if res
end

#empty? ⇒ Boolean

Returns true if the Source is exhausted.

Returns:

  • (Boolean) —

    true if the Source is exhausted



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# File 'lib/rexml/source.rb', line 108

def empty?
  @buffer == ""
end

#match(pattern, cons = false) ⇒ Object 



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# File 'lib/rexml/source.rb', line 101

def match(pattern, cons=false)
  md = pattern.match(@buffer)
  @buffer = $' if cons and md
  return md
end

#match_to(char, pattern) ⇒ Object 



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# File 'lib/rexml/source.rb', line 91

def match_to( char, pattern )
  return pattern.match(@buffer)
end

#match_to_consume(char, pattern) ⇒ Object 



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# File 'lib/rexml/source.rb', line 95

def match_to_consume( char, pattern )
  md = pattern.match(@buffer)
  @buffer = $'
  return md
end

#position ⇒ Object 



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# File 'lib/rexml/source.rb', line 112

def position
  @orig.index( @buffer )
end

#read ⇒ Object 



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# File 'lib/rexml/source.rb', line 84

def read
end

#scan(pattern, cons = false) ⇒ Object

Scans the source for a given pattern. Note, that this is not your usual scan() method. For one thing, the pattern argument has some requirements; for another, the source can be consumed. You can easily confuse this method. Originally, the patterns were easier to construct and this method more robust, because this method generated search regexps on the fly; however, this was computationally expensive and slowed down the entire REXML package considerably, since this is by far the most commonly called method. /^s*(#pattern, with no groups)(.*)/. The first group will be returned; the second group is used if the consume flag is set. everything after it in the Source. pattern is not found.

Parameters:

  • pattern —

    must be a Regexp, and must be in the form of

  • consume —

    if true, the pattern returned will be consumed, leaving

Returns:

  • the pattern, if found, or nil if the Source is empty or the



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# File 'lib/rexml/source.rb', line 77

def scan(pattern, cons=false)
  return nil if @buffer.nil?
  rv = @buffer.scan(pattern)
  @buffer = $' if cons and rv.size>0
  rv
end