core :: UTF8Codec :: defaultinit
# Codec supporting UTF-8
private class UTF8Codec
super Codec
redef fun char_max_size do return 4
redef fun codet_size do return 1
redef fun max_lookahead do return 4
redef fun encode_char(c) do
var ns = new CString(c.u8char_len)
add_char_to(c, ns)
return ns
end
redef fun add_char_to(c, stream) do
c.u8char_tos(stream, c.u8char_len)
return c.u8char_len
end
redef fun encode_string(s) do
var buf = new Bytes.with_capacity(s.byte_length)
add_string_to(s, buf)
return buf
end
redef fun add_string_to(s, b) do
s.append_to_bytes(b)
return s.byte_length
end
redef fun is_valid_char(ns, len) do
if len == 0 then return 2
if not ns[0].is_valid_utf8_start then return 2
for i in [1 .. len[ do if ns[i] & 0b1100_0000 != 0b1000_0000 then return 2
if len != ns[0].u8len then return 1
return 0
end
redef fun decode_char(b) do
var c = b.char_at(0)
var cp = c.code_point
if cp >= 0xD800 and cp <= 0xDFFF then return 0xFFFD.code_point
if cp == 0xFFFE or cp == 0xFFFF then return 0xFFFD.code_point
return c
end
redef fun decode_string(ns, len) do
assert len >= 0
var ret = ns.to_s_unsafe(len, copy=false)
var rit = ret.as(FlatString).items
if rit == ns then
var nns = new CString(len)
rit.copy_to(nns, len, 0, 0)
return nns.to_s_unsafe(ret.byte_length, ret.length, copy=false)
end
return ret
end
end
lib/core/codecs/utf8.nit:22,1--81,3