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UTF-8文字列を1文字ずつで分解するLuaスクリプト
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-- The MIT License (MIT) | |
-- | |
-- Copyright (c) 2018 oov | |
-- | |
-- Permission is hereby granted, free of charge, to any person obtaining a copy of | |
-- this software and associated documentation files (the "Software"), to deal in | |
-- the Software without restriction, including without limitation the rights to | |
-- use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of | |
-- the Software, and to permit persons to whom the Software is furnished to do so, | |
-- subject to the following conditions: | |
-- | |
-- The above copyright notice and this permission notice shall be included in all | |
-- copies or substantial portions of the Software. | |
-- | |
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS | |
-- FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR | |
-- COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER | |
-- IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN | |
-- CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. | |
-- Reference: https://tools.ietf.org/html/rfc3629#section-4 | |
local function split_by_utf8_char(s) | |
local r, cp, p, ln = {}, {}, 1, s:len() | |
local c1, c2, c3, c4 | |
while p <= ln do | |
c1 = s:byte(p) | |
if 0x00 <= c1 and c1 <= 0x7f then | |
table.insert(r, string.char(c1)) | |
table.insert(cp, c1) | |
elseif p + 1 <= ln then | |
c2 = s:byte(p + 1) | |
if 0xc2 <= c1 and c1 <= 0xdf and 0x80 <= c2 and c2 <= 0xbf then | |
table.insert(r, string.char(c1, c2)) | |
table.insert(cp, (c1 - 0xc0) * 0x40 + (c2 - 0x80)) | |
p = p + 1 | |
elseif p + 2 <= ln then | |
c3 = s:byte(p + 2) | |
if (c1 == 0xe0 and 0xa0 <= c2 and c2 <= 0xbf and 0x80 <= c3 and c3 <= 0xbf)or | |
(0xe1 <= c1 and c1 <= 0xec and 0x80 <= c2 and c2 <= 0xbf and 0x80 <= c3 and c3 <= 0xbf)or | |
(c1 == 0xed and 0x80 <= c2 and c2 <= 0x9f and 0x80 <= c3 and c3 <= 0xbf)or | |
(0xee <= c1 and c1 <= 0xef and 0x80 <= c2 and c2 <= 0xbf and 0x80 <= c3 and c3 <= 0xbf) then | |
table.insert(r, string.char(c1, c2, c3)) | |
table.insert(cp, (c1 - 0xe0) * 0x1000 + (c2 - 0x80) * 0x40 + (c3 - 0x80)) | |
p = p + 2 | |
elseif p + 3 <= ln then | |
c4 = s:byte(p + 3) | |
if (c1 == 0xf0 and 0x90 <= c2 and c2 <= 0xbf and 0x80 <= c3 and c3 <= 0xbf and 0x80 <= c4 and c4 <= 0xbf)or | |
(0xf1 <= c1 and c1 <= 0xf3 and 0x80 <= c2 and c2 <= 0xbf and 0x80 <= c3 and c3 <= 0xbf and 0x80 <= c4 and c4 <= 0xbf)or | |
(c1 == 0xf4 and 0x80 <= c2 and c2 <= 0x8f and 0x80 <= c3 and c3 <= 0xbf and 0x80 <= c4 and c4 <= 0xbf) then | |
table.insert(r, string.char(c1, c2, c3, c4)) | |
table.insert(cp, (c1 - 0xf0) * 0x40000 + (c2 - 0x80) * 0x1000 + (c3 - 0x80) * 0x40 + (c3 - 0x80)) | |
p = p + 3 | |
end | |
end | |
end | |
end | |
p = p + 1 | |
end | |
return r, cp | |
end |
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