return ns_i
end
- private fun byte_to_char_index(index: Int): Int do
- var ln = _bytelen
- assert index >= 0
- assert index < ln
-
- var pos = _bytepos
- # Find best insertion point
- var delta_begin = index
- var delta_end = (ln - 1) - index
- var delta_cache = (pos - index).abs
- var min = delta_begin
+ # By escaping `self` to C, how many more bytes will be needed ?
+ #
+ # This enables a double-optimization in `escape_to_c` since if this
+ # method returns 0, then `self` does not need escaping and can be
+ # returned as-is
+ protected fun chars_to_escape_to_c: Int do
var its = _items
-
- if delta_cache < min then min = delta_cache
- if delta_end < min then min = delta_end
-
- var ns_i: Int
- var my_i: Int
-
- if min == delta_begin then
- ns_i = first_byte
- my_i = 0
- else if min == delta_cache then
- ns_i = pos
- my_i = _position
- else
- ns_i = its.find_beginning_of_char_at(last_byte)
- my_i = length - 1
+ var max = last_byte
+ var pos = first_byte
+ var req_esc = 0
+ while pos <= max do
+ var c = its[pos]
+ if c == 0x0Au8 then
+ req_esc += 1
+ else if c == 0x09u8 then
+ req_esc += 1
+ else if c == 0x22u8 then
+ req_esc += 1
+ else if c == 0x27u8 then
+ req_esc += 1
+ else if c == 0x5Cu8 then
+ req_esc += 1
+ else if c < 32u8 then
+ req_esc += 3
+ end
+ pos += 1
end
+ return req_esc
+ end
- my_i = its.byte_to_char_index_cached(index, my_i, ns_i)
-
- _position = my_i
- _bytepos = index
-
- return my_i
+ redef fun escape_to_c do
+ var ln_extra = chars_to_escape_to_c
+ if ln_extra == 0 then return self.to_s
+ var its = _items
+ var max = last_byte
+ var nlen = _bytelen + ln_extra
+ var nns = new NativeString(nlen)
+ var pos = first_byte
+ var opos = 0
+ while pos <= max do
+ var c = its[pos]
+ # Special codes:
+ #
+ # Any byte with value < 32 is a control character
+ # All their uses will be replaced by their octal
+ # value in C.
+ #
+ # There are two exceptions however:
+ #
+ # * 0x09 => \t
+ # * 0x0A => \n
+ #
+ # Aside from the code points above, the following are:
+ #
+ # * 0x22 => \"
+ # * 0x27 => \'
+ # * 0x5C => \\
+ if c == 0x09u8 then
+ nns[opos] = 0x5Cu8
+ nns[opos + 1] = 0x74u8
+ opos += 2
+ else if c == 0x0Au8 then
+ nns[opos] = 0x5Cu8
+ nns[opos + 1] = 0x6Eu8
+ opos += 2
+ else if c == 0x22u8 then
+ nns[opos] = 0x5Cu8
+ nns[opos + 1] = 0x22u8
+ opos += 2
+ else if c == 0x27u8 then
+ nns[opos] = 0x5Cu8
+ nns[opos + 1] = 0x27u8
+ opos += 2
+ else if c == 0x5Cu8 then
+ nns[opos] = 0x5Cu8
+ nns[opos + 1] = 0x5Cu8
+ opos += 2
+ else if c < 32u8 then
+ nns[opos] = 0x5Cu8
+ nns[opos + 1] = 0x30u8
+ nns[opos + 2] = ((c & 0x38u8) >> 3) + 0x30u8
+ nns[opos + 3] = (c & 0x07u8) + 0x30u8
+ opos += 4
+ else
+ nns[opos] = c
+ opos += 1
+ end
+ pos += 1
+ end
+ return nns.to_s_with_length(nlen)
end
redef fun [](index) do return _items.char_at(char_to_byte_index(index))
redef var length is lazy do
if _bytelen == 0 then return 0
- var st = _first_byte
- var its = _items
- var ln = 0
- var lst = _last_byte
- while st <= lst do
- st += its.length_of_char_at(st)
- ln += 1
- end
- return ln
+ return _items.utf8_length(_first_byte, _last_byte)
end
redef fun reversed
nitlanguage / nit.git / blobdiff