Class: String

Inherits:
Object
  • Object
show all
Defined in:
lib/hpricot/xs.rb

Overview

Pure-Ruby replacement for the fast_xs C extension.

This is a BEHAVIOUR-PRESERVING port. It reproduces what ext/fast_xs/fast_xs.c does, including two things that are arguably wrong, because the differential harness requires byte-for-byte parity and changing behaviour belongs in a separate commit from replacing an implementation:

* XML-invalid control characters become "*" rather than being escaped or
dropped. Tab, newline and carriage return pass through untouched.
* In BINARY strings the CP-1252 range is mapped to Unicode, but the five
bytes CP-1252 leaves undefined (129, 141, 143, 144, 157) become "*"
rather than the numeric reference fast_xs.c's own comments claim. That is
the `#define p(x) (x-128)` bug at fast_xs.c:32.

Note that "'" is deliberately NOT escaped, matching the C version.

Constant Summary collapse

XS_ESCAPES = 
{ '&' => '&amp;', '<' => '&lt;', '>' => '&gt;', '"' => '&quot;' }.freeze
XS_INVALID_CONTROL =

Control characters that are invalid in XML. 9 (tab), 10 (LF) and 13 (CR) are valid and pass through.

((0..8).to_a + [11, 12] + (14..31).to_a).freeze
XS_CP1252 =

CP-1252 codepoints for bytes 128-159, which is where CP-1252 differs from Latin-1. nil marks the five undefined positions, which become "*".

[
  0x20AC, nil,    0x201A, 0x0192, 0x201E, 0x2026, 0x2020, 0x2021,
  0x02C6, 0x2030, 0x0160, 0x2039, 0x0152, nil,    0x017D, nil,
  nil,    0x2018, 0x2019, 0x201C, 0x201D, 0x2022, 0x2013, 0x2014,
  0x02DC, 0x2122, 0x0161, 0x203A, 0x0153, nil,    0x017E, 0x0178
].freeze

Instance Method Summary collapse

Instance Method Details

#fast_xs ⇒ Object 



34
35
36
37
38
39
40
41
42
43
44
45
 
# File 'lib/hpricot/xs.rb', line 34

def fast_xs
  binary = !encoding.ascii_compatible? || encoding == Encoding::BINARY
  out = +''

  if binary || !valid_encoding?
    each_byte { |b| out << xs_byte(b) }
  else
    each_char { |c| out << xs_char(c) }
  end

  out
end