A Source can be searched for patterns, and wraps buffers and other objects and provides consumption of text
The current buffer (what we’re going to read next)
The line number of the last consumed text
# File tmp/rubies/ruby-2.5.9/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
Constructor @param arg must be a String, and should be a valid XML document @param encoding if non-null, sets the encoding of the source to this value, overriding all encoding detection
# File tmp/rubies/ruby-2.5.9/lib/rexml/source.rb, line 87
def consume( pattern )
@buffer = $' if pattern.match( @buffer )
end
# File tmp/rubies/ruby-2.5.9/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
@return the current line in the source
# File tmp/rubies/ruby-2.5.9/lib/rexml/source.rb, line 125
def detect_encoding
buffer_encoding = @buffer.encoding
detected_encoding = "UTF-8"
begin
@buffer.force_encoding("ASCII-8BIT")
if @buffer[0, 2] == "\xfe\xff"
@buffer[0, 2] = ""
detected_encoding = "UTF-16BE"
elsif @buffer[0, 2] == "\xff\xfe"
@buffer[0, 2] = ""
detected_encoding = "UTF-16LE"
elsif @buffer[0, 3] == "\xef\xbb\xbf"
@buffer[0, 3] = ""
detected_encoding = "UTF-8"
end
ensure
@buffer.force_encoding(buffer_encoding)
end
self.encoding = detected_encoding
end
# File tmp/rubies/ruby-2.5.9/lib/rexml/source.rb, line 108
def empty?
@buffer == ""
end
@return true if the Source is exhausted
# File tmp/rubies/ruby-2.5.9/lib/rexml/source.rb, line 56
def encoding=(enc)
return unless super
encoding_updated
end
Inherited from Encoding Overridden to support optimized en/decoding
# File tmp/rubies/ruby-2.5.9/lib/rexml/source.rb, line 146
def encoding_updated
if @encoding != 'UTF-8'
@buffer = decode(@buffer)
@to_utf = true
else
@to_utf = false
@buffer.force_encoding ::Encoding::UTF_8
end
end
# File tmp/rubies/ruby-2.5.9/lib/rexml/source.rb, line 101
def match(pattern, cons=false)
md = pattern.match(@buffer)
@buffer = $' if cons and md
return md
end
# File tmp/rubies/ruby-2.5.9/lib/rexml/source.rb, line 91
def match_to( char, pattern )
return pattern.match(@buffer)
end
# File tmp/rubies/ruby-2.5.9/lib/rexml/source.rb, line 95
def match_to_consume( char, pattern )
md = pattern.match(@buffer)
@buffer = $'
return md
end
# File tmp/rubies/ruby-2.5.9/lib/rexml/source.rb, line 112
def position
@orig.index( @buffer )
end
# File tmp/rubies/ruby-2.5.9/lib/rexml/source.rb, line 84
def read
end
# File tmp/rubies/ruby-2.5.9/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
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. @param pattern must be a Regexp, and must be in the form of /^s*(#{your pattern, with no groups})(.*)/. The first group will be returned; the second group is used if the consume flag is set. @param consume if true, the pattern returned will be consumed, leaving everything after it in the Source. @return the pattern, if found, or nil if the Source is empty or the pattern is not found.