Class: Opal::Nodes::StringNode

Inherits:
Base
  • Object
show all
Defined in:
opal/lib/opal/nodes/literal.rb

Constant Summary

ESCAPE_CHARS = 
{
  ?a => '\\u0007',
  ?e => '\\u001b'
}
ESCAPE_REGEX = 
/(\\+)([#{ ESCAPE_CHARS.keys.join('') }])/

Instance Attribute Summary

Attributes inherited from Base

#compiler, #type

Instance Method Summary collapse

Methods inherited from Base

#add_gvar, #add_ivar, #add_local, #add_temp, #children, children, #class_variable_owner, #closest_module_node, #comments, #compile_to_fragments, #error, #expr, #expr?, #expr_or_nil, #fragment, handle, handlers, #has_rescue_else?, #helper, #in_ensure, #in_ensure?, #in_while?, #initialize, #process, #push, #recv, #recv?, #s, #scope, #stmt, #stmt?, truthy_optimize?, #unshift, #while_loop, #with_temp, #wrap

Methods included from Helpers

#conditional_send, #current_indent, #empty_line, #indent, #js_falsy, #js_truthy, #js_truthy_optimize, #line, #mid_to_jsid, #property, #valid_name?

Constructor Details

This class inherits a constructor from Opal::Nodes::Base

Instance Method Details

#compile ⇒ Object 



55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
 
# File 'opal/lib/opal/nodes/literal.rb', line 55

def compile
  string_value = value
  encoding = string_value.encoding
  should_encode = encoding != Encoding::UTF_8

  if should_encode
    string_value = string_value.force_encoding('UTF-8')
  end

  sanitized_value = string_value.inspect.gsub(/\\u\{([0-9a-f]+)\}/) do |match|
    code_point = $1.to_i(16)
    to_utf16(code_point)
  end
  push translate_escape_chars(sanitized_value)

  if should_encode && RUBY_ENGINE != 'opal'
    push '.$force_encoding("', encoding.name, '")'
  end
end

#to_utf16(code_point) ⇒ Object

http://www.2ality.com/2013/09/javascript-unicode.html



76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
 
# File 'opal/lib/opal/nodes/literal.rb', line 76

def to_utf16(code_point)
  ten_bits = 0b1111111111
  u = -> (code_unit) { '\\u'+code_unit.to_s(16).upcase }

  return u.(code_point) if code_point <= 0xFFFF

  code_point -= 0x10000

  # Shift right to get to most significant 10 bits
  lead_surrogate = 0xD800 + (code_point >> 10)

  # Mask to get least significant 10 bits
  tail_surrogate = 0xDC00 + (code_point & ten_bits)

  u.(lead_surrogate) + u.(tail_surrogate)
end

#translate_escape_chars(inspect_string) ⇒ Object 



45
46
47
48
49
50
51
52
53
 
# File 'opal/lib/opal/nodes/literal.rb', line 45

def translate_escape_chars(inspect_string)
  inspect_string.gsub(ESCAPE_REGEX) do |original|
    if $1.length.even?
      original
    else
      $1.chop + ESCAPE_CHARS[$2]
    end
  end
end