mirror of
https://gerrit.wikimedia.org/r/mediawiki/extensions/Scribunto
synced 2024-12-18 10:53:37 +00:00
1252 lines
31 KiB
Lua
1252 lines
31 KiB
Lua
local ustring = {}
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-- Copy these, just in case
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local S = {
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byte = string.byte,
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char = string.char,
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len = string.len,
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sub = string.sub,
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find = string.find,
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match = string.match,
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gmatch = string.gmatch,
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gsub = string.gsub,
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format = string.format,
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}
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---- Configuration ----
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-- To limit the length of strings or patterns processed, set these
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ustring.maxStringLength = math.huge
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ustring.maxPatternLength = math.huge
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---- Utility functions ----
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local function checkType( name, argidx, arg, expecttype, nilok )
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if arg == nil and nilok then
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return
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end
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if type( arg ) ~= expecttype then
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local msg = S.format( "bad argument #%d to '%s' (%s expected, got %s)",
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argidx, name, expecttype, type( arg )
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)
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error( msg, 3 )
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end
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end
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local function checkString( name, s )
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if type( s ) == 'number' then
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s = tostring( s )
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end
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if type( s ) ~= 'string' then
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local msg = S.format( "bad argument #1 to '%s' (string expected, got %s)",
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name, type( s )
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)
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error( msg, 3 )
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end
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if S.len( s ) > ustring.maxStringLength then
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local msg = S.format( "bad argument #1 to '%s' (string is longer than %d bytes)",
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name, ustring.maxStringLength
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)
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error( msg, 3 )
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end
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end
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local function checkPattern( name, pattern )
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if type( pattern ) == 'number' then
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pattern = tostring( pattern )
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end
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if type( pattern ) ~= 'string' then
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local msg = S.format( "bad argument #2 to '%s' (string expected, got %s)",
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name, type( pattern )
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)
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error( msg, 3 )
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end
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if S.len( pattern ) > ustring.maxPatternLength then
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local msg = S.format( "bad argument #2 to '%s' (pattern is longer than %d bytes)",
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name, ustring.maxPatternLength
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)
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error( msg, 3 )
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end
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end
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-- A private helper that splits a string into codepoints, and also collects the
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-- starting position of each character and the total length in codepoints.
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--
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-- @param s string utf8-encoded string to decode
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-- @return table
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local function utf8_explode( s )
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local ret = {
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len = 0,
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codepoints = {},
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bytepos = {},
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}
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local i = 1
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local l = S.len( s )
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local cp, b, b2, trail
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local min
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while i <= l do
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b = S.byte( s, i )
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if b < 0x80 then
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-- 1-byte code point, 00-7F
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cp = b
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trail = 0
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min = 0
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elseif b < 0xc2 then
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-- Either a non-initial code point (invalid here) or
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-- an overlong encoding for a 1-byte code point
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return nil
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elseif b < 0xe0 then
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-- 2-byte code point, C2-DF
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trail = 1
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cp = b - 0xc0
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min = 0x80
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elseif b < 0xf0 then
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-- 3-byte code point, E0-EF
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trail = 2
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cp = b - 0xe0
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min = 0x800
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elseif b < 0xf4 then
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-- 4-byte code point, F0-F3
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trail = 3
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cp = b - 0xf0
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min = 0x10000
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elseif b == 0xf4 then
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-- 4-byte code point, F4
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-- Make sure it doesn't decode to over U+10FFFF
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if S.byte( s, i + 1 ) > 0x8f then
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return nil
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end
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trail = 3
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cp = 4
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min = 0x100000
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else
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-- Code point over U+10FFFF, or invalid byte
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return nil
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end
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-- Check subsequent bytes for multibyte code points
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for j = i + 1, i + trail do
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b = S.byte( s, j )
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if not b or b < 0x80 or b > 0xbf then
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return nil
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end
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cp = cp * 0x40 + b - 0x80
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end
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if cp < min then
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-- Overlong encoding
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return nil
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end
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ret.codepoints[#ret.codepoints + 1] = cp
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ret.bytepos[#ret.bytepos + 1] = i
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ret.len = ret.len + 1
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i = i + 1 + trail
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end
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-- Two past the end (for sub with empty string)
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ret.bytepos[#ret.bytepos + 1] = l + 1
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ret.bytepos[#ret.bytepos + 1] = l + 1
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return ret
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end
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-- A private helper that finds the character offset for a byte offset.
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--
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-- @param cps table from utf8_explode
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-- @param i int byte offset
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-- @return int
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local function cpoffset( cps, i )
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local min, max, p = 0, cps.len + 1
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if i == 0 then
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return 0
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end
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while min + 1 < max do
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p = math.floor( ( min + max ) / 2 ) + 1
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if cps.bytepos[p] <= i then
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min = p - 1
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end
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if cps.bytepos[p] >= i then
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max = p - 1
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end
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end
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return min + 1
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end
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---- Trivial functions ----
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-- These functions are the same as the standard string versions
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ustring.byte = string.byte
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ustring.format = string.format
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ustring.rep = string.rep
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---- Non-trivial functions ----
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-- These functions actually have to be UTF-8 aware
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-- Determine if a string is valid UTF-8
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--
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-- @param s string
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-- @return boolean
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function ustring.isutf8( s )
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checkString( 'isutf8', s )
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return utf8_explode( s ) ~= nil
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end
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-- Return the byte offset of a character in a string
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--
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-- @param s string
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-- @param l int codepoint number [default 1]
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-- @param i int starting byte offset [default 1]
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-- @return int|nil
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function ustring.byteoffset( s, l, i )
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checkString( 'byteoffset', s )
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checkType( 'byteoffset', 2, l, 'number', true )
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checkType( 'byteoffset', 3, i, 'number', true )
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local cps = utf8_explode( s )
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if cps == nil then
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error( "bad argument #1 for 'byteoffset' (string is not UTF-8)", 2 )
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end
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i = i or 1
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if i < 0 then
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i = S.len( s ) + i + 1
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end
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if i < 1 or i > S.len( s ) then
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return nil
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end
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local p = cpoffset( cps, i )
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if l > 0 and cps.bytepos[p] == i then
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l = l - 1
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end
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if p + l > cps.len then
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return nil
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end
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return cps.bytepos[p + l]
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end
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-- Return codepoints from a string
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--
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-- @see string.byte
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-- @param s string
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-- @param i int Starting character [default 1]
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-- @param j int Ending character [default i]
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-- @return int* Zero or more codepoints
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function ustring.codepoint( s, i, j )
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checkString( 'codepoint', s )
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checkType( 'codepoint', 2, i, 'number', true )
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checkType( 'codepoint', 3, j, 'number', true )
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local cps = utf8_explode( s )
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if cps == nil then
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error( "bad argument #1 for 'codepoint' (string is not UTF-8)", 2 )
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end
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i = i or 1
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if i < 0 then
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i = cps.len + i + 1
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end
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j = j or i
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if j < 0 then
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j = cps.len + j + 1
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end
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if j < i then
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return -- empty result set
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end
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i = math.max( 1, math.min( i, cps.len + 1 ) )
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j = math.max( 1, math.min( j, cps.len + 1 ) )
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return unpack( cps.codepoints, i, j )
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end
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-- Return an iterator over the codepoint (as integers)
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-- for cp in ustring.gcodepoint( s ) do ... end
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--
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-- @param s string
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-- @param i int Starting character [default 1]
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-- @param j int Ending character [default -1]
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-- @return function
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-- @return nil
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-- @return nil
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function ustring.gcodepoint( s, i, j )
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checkString( 'gcodepoint', s )
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checkType( 'gcodepoint', 2, i, 'number', true )
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checkType( 'gcodepoint', 3, j, 'number', true )
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local cps = utf8_explode( s )
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if cps == nil then
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error( "bad argument #1 for 'gcodepoint' (string is not UTF-8)", 2 )
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end
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i = i or 1
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if i < 0 then
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i = cps.len + i + 1
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end
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j = j or -1
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if j < 0 then
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j = cps.len + j + 1
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end
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if j < i then
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return function ()
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return nil
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end
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end
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i = math.max( 1, math.min( i, cps.len + 1 ) )
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j = math.max( 1, math.min( j, cps.len + 1 ) )
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return function ()
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if i <= j then
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local ret = cps.codepoints[i]
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i = i + 1
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return ret
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end
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return nil
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end
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end
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-- Convert codepoints to a string
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--
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-- @see string.char
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-- @param ... int List of codepoints
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-- @return string
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local function internalChar( t, s, e )
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local ret = {}
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for i = s, e do
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local v = t[i]
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if type( v ) ~= 'number' then
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checkType( 'char', i, v, 'number' )
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end
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v = math.floor( v )
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if v < 0 or v > 0x10ffff then
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error( S.format( "bad argument #%d to 'char' (value out of range)", i ), 2 )
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elseif v < 0x80 then
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ret[#ret + 1] = v
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elseif v < 0x800 then
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ret[#ret + 1] = 0xc0 + math.floor( v / 0x40 ) % 0x20
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ret[#ret + 1] = 0x80 + v % 0x40
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elseif v < 0x10000 then
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ret[#ret + 1] = 0xe0 + math.floor( v / 0x1000 ) % 0x10
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ret[#ret + 1] = 0x80 + math.floor( v / 0x40 ) % 0x40
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ret[#ret + 1] = 0x80 + v % 0x40
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else
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ret[#ret + 1] = 0xf0 + math.floor( v / 0x40000 ) % 0x08
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ret[#ret + 1] = 0x80 + math.floor( v / 0x1000 ) % 0x40
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ret[#ret + 1] = 0x80 + math.floor( v / 0x40 ) % 0x40
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ret[#ret + 1] = 0x80 + v % 0x40
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end
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end
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return S.char( unpack( ret ) )
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end
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function ustring.char( ... )
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return internalChar( { ... }, 1, select( '#', ... ) )
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end
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-- Return the length of a string in codepoints, or
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-- nil if the string is not valid UTF-8.
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--
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-- @see string.len
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-- @param string
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-- @return int|nil
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function ustring.len( s )
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checkString( 'len', s )
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local cps = utf8_explode( s )
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if cps == nil then
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return nil
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else
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return cps.len
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end
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end
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-- Private function to return a substring of a string
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--
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-- @param s string
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-- @param cps table Exploded string
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-- @param i int Starting character [default 1]
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-- @param j int Ending character [default -1]
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-- @return string
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local function sub( s, cps, i, j )
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return S.sub( s, cps.bytepos[i], cps.bytepos[j+1] - 1 )
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end
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-- Return a substring of a string
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--
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-- @see string.sub
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-- @param s string
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-- @param i int Starting character [default 1]
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-- @param j int Ending character [default -1]
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-- @return string
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function ustring.sub( s, i, j )
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checkString( 'sub', s )
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checkType( 'sub', 2, i, 'number', true )
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checkType( 'sub', 3, j, 'number', true )
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local cps = utf8_explode( s )
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if cps == nil then
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error( "bad argument #1 for 'sub' (string is not UTF-8)", 2 )
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end
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i = i or 1
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if i < 0 then
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i = cps.len + i + 1
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end
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j = j or -1
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if j < 0 then
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j = cps.len + j + 1
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end
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if j < i then
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return ''
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end
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i = math.max( 1, math.min( i, cps.len + 1 ) )
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j = math.max( 1, math.min( j, cps.len + 1 ) )
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return sub( s, cps, i, j )
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end
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---- Table-driven functions ----
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-- These functions load a conversion table when called
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||
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-- Convert a string to uppercase
|
||
--
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-- @see string.upper
|
||
-- @param s string
|
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-- @return string
|
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function ustring.upper( s )
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checkString( 'upper', s )
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local map = require 'ustring/upper';
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local ret = S.gsub( s, '([^\128-\191][\128-\191]*)', map )
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return ret
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||
end
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||
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||
-- Convert a string to lowercase
|
||
--
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||
-- @see string.lower
|
||
-- @param s string
|
||
-- @return string
|
||
function ustring.lower( s )
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checkString( 'lower', s )
|
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local map = require 'ustring/lower';
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local ret = S.gsub( s, '([^\128-\191][\128-\191]*)', map )
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return ret
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||
end
|
||
|
||
---- Pattern functions ----
|
||
-- Ugh. Just ugh.
|
||
|
||
-- Cache for character sets (e.g. [a-z])
|
||
local charset_cache = {}
|
||
setmetatable( charset_cache, { __weak = 'kv' } )
|
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|
||
-- Private function to find a pattern in a string
|
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-- Yes, this basically reimplements the whole of Lua's pattern matching, in
|
||
-- Lua.
|
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--
|
||
-- @see ustring.find
|
||
-- @param s string
|
||
-- @param cps table Exploded string
|
||
-- @param rawpat string Pattern
|
||
-- @param pattern table Exploded pattern
|
||
-- @param init int Starting index
|
||
-- @param noAnchor boolean True to ignore '^'
|
||
-- @return int starting index of the match
|
||
-- @return int ending index of the match
|
||
-- @return string|int* captures
|
||
local function find( s, cps, rawpat, pattern, init, noAnchor )
|
||
local charsets = require 'ustring/charsets'
|
||
local anchor = false
|
||
local ncapt, captures
|
||
local captparen = {}
|
||
|
||
-- Extract the value of a capture from the
|
||
-- upvalues ncapt and capture.
|
||
local function getcapt( n, err, errl )
|
||
if n > ncapt then
|
||
error( err, errl + 1 )
|
||
elseif type( captures[n] ) == 'table' then
|
||
if captures[n][2] == '' then
|
||
error( err, errl + 1 )
|
||
end
|
||
return sub( s, cps, captures[n][1], captures[n][2] ), captures[n][2] - captures[n][1] + 1
|
||
else
|
||
return captures[n], math.floor( math.log10( captures[n] ) ) + 1
|
||
end
|
||
end
|
||
|
||
local match, match_charset, parse_charset
|
||
|
||
-- Main matching function. Uses tail recursion where possible.
|
||
-- Returns the position of the character after the match, and updates the
|
||
-- upvalues ncapt and captures.
|
||
match = function ( sp, pp )
|
||
local c = pattern.codepoints[pp]
|
||
if c == 0x28 then -- '(': starts capture group
|
||
ncapt = ncapt + 1
|
||
captparen[ncapt] = pp
|
||
local ret
|
||
if pattern.codepoints[pp + 1] == 0x29 then -- ')': Pattern is '()', capture position
|
||
captures[ncapt] = sp
|
||
ret = match( sp, pp + 2 )
|
||
else
|
||
-- Start capture group
|
||
captures[ncapt] = { sp, '' }
|
||
ret = match( sp, pp + 1 )
|
||
end
|
||
if ret then
|
||
return ret
|
||
else
|
||
-- Failed, rollback
|
||
ncapt = ncapt - 1
|
||
return nil
|
||
end
|
||
elseif c == 0x29 then -- ')': ends capture group, pop current capture index from stack
|
||
for n = ncapt, 1, -1 do
|
||
if type( captures[n] ) == 'table' and captures[n][2] == '' then
|
||
captures[n][2] = sp - 1
|
||
local ret = match( sp, pp + 1 )
|
||
if ret then
|
||
return ret
|
||
else
|
||
-- Failed, rollback
|
||
captures[n][2] = ''
|
||
return nil
|
||
end
|
||
end
|
||
end
|
||
error( 'Unmatched close-paren at pattern character ' .. pp, 3 )
|
||
elseif c == 0x5b then -- '[': starts character set
|
||
return match_charset( sp, parse_charset( pp ) )
|
||
elseif c == 0x5d then -- ']'
|
||
error( 'Unmatched close-bracket at pattern character ' .. pp, 3 )
|
||
elseif c == 0x25 then -- '%'
|
||
c = pattern.codepoints[pp + 1]
|
||
if charsets[c] then -- A character set like '%a'
|
||
return match_charset( sp, pp + 2, charsets[c] )
|
||
elseif c == 0x62 then -- '%b': balanced delimiter match
|
||
local d1 = pattern.codepoints[pp + 2]
|
||
local d2 = pattern.codepoints[pp + 3]
|
||
if not d1 or not d2 then
|
||
error( 'malformed pattern (missing arguments to \'%b\')', 3 )
|
||
end
|
||
if cps.codepoints[sp] ~= d1 then
|
||
return nil
|
||
end
|
||
sp = sp + 1
|
||
local ct = 1
|
||
while true do
|
||
c = cps.codepoints[sp]
|
||
sp = sp + 1
|
||
if not c then
|
||
return nil
|
||
elseif c == d2 then
|
||
if ct == 1 then
|
||
return match( sp, pp + 4 )
|
||
end
|
||
ct = ct - 1
|
||
elseif c == d1 then
|
||
ct = ct + 1
|
||
end
|
||
end
|
||
elseif c == 0x66 then -- '%f': frontier pattern match
|
||
if pattern.codepoints[pp + 2] ~= 0x5b then
|
||
error( 'missing \'[\' after %f in pattern at pattern character ' .. pp, 3 )
|
||
end
|
||
local pp, charset = parse_charset( pp + 2 )
|
||
local c1 = cps.codepoints[sp - 1] or 0
|
||
local c2 = cps.codepoints[sp] or 0
|
||
if not charset[c1] and charset[c2] then
|
||
return match( sp, pp )
|
||
else
|
||
return nil
|
||
end
|
||
elseif c >= 0x30 and c <= 0x39 then -- '%0' to '%9': backreference
|
||
local m, l = getcapt( c - 0x30, 'invalid capture index %' .. c .. ' at pattern character ' .. pp, 3 )
|
||
local ep = math.min( cps.len + 1, sp + l )
|
||
if sub( s, cps, sp, ep - 1 ) == m then
|
||
return match( ep, pp + 2 )
|
||
else
|
||
return nil
|
||
end
|
||
elseif not c then -- percent at the end of the pattern
|
||
error( 'malformed pattern (ends with \'%\')', 3 )
|
||
else -- something else, treat as a literal
|
||
return match_charset( sp, pp + 2, { [c] = 1 } )
|
||
end
|
||
elseif c == 0x2e then -- '.': match anything
|
||
if not charset_cache['.'] then
|
||
local t = {}
|
||
setmetatable( t, { __index = function ( t, k ) return k end } )
|
||
charset_cache['.'] = { 1, t }
|
||
end
|
||
return match_charset( sp, pp + 1, charset_cache['.'][2] )
|
||
elseif c == nil then -- end of pattern
|
||
return sp
|
||
elseif c == 0x24 and pattern.len == pp then -- '$': assert end of string
|
||
return ( sp == cps.len + 1 ) and sp or nil
|
||
else
|
||
-- Any other character matches itself
|
||
return match_charset( sp, pp + 1, { [c] = 1 } )
|
||
end
|
||
end
|
||
|
||
-- Parse a bracketed character set (e.g. [a-z])
|
||
-- Returns the position after the set and a table holding the matching characters
|
||
parse_charset = function ( pp )
|
||
local _, ep
|
||
local epp = pattern.bytepos[pp] + 1
|
||
if S.sub( rawpat, epp, epp ) == '^' then
|
||
epp = epp + 1
|
||
end
|
||
if S.sub( rawpat, epp, epp ) == ']' then
|
||
-- Lua's string module effectively does this
|
||
epp = epp + 1
|
||
end
|
||
repeat
|
||
_, ep = S.find( rawpat, ']', epp, true )
|
||
if not ep then
|
||
error( 'Missing close-bracket for character set beginning at pattern character ' .. pp, 3 )
|
||
end
|
||
epp = ep + 1
|
||
until S.byte( rawpat, ep - 1 ) ~= 0x25 or S.byte( rawpat, ep - 2 ) == 0x25
|
||
local key = S.sub( rawpat, pattern.bytepos[pp], ep )
|
||
if charset_cache[key] then
|
||
local pl, cs = unpack( charset_cache[key] )
|
||
return pp + pl, cs
|
||
end
|
||
|
||
local p0 = pp
|
||
local cs = {}
|
||
local csrefs = { cs }
|
||
local invert = false
|
||
pp = pp + 1
|
||
if pattern.codepoints[pp] == 0x5e then -- '^'
|
||
invert = true
|
||
pp = pp + 1
|
||
end
|
||
local first = true
|
||
while true do
|
||
local c = pattern.codepoints[pp]
|
||
if not first and c == 0x5d then -- closing ']'
|
||
pp = pp + 1
|
||
break
|
||
elseif c == 0x25 then -- '%'
|
||
c = pattern.codepoints[pp + 1]
|
||
if charsets[c] then
|
||
csrefs[#csrefs + 1] = charsets[c]
|
||
else
|
||
cs[c] = 1
|
||
end
|
||
pp = pp + 2
|
||
elseif pattern.codepoints[pp + 1] == 0x2d and pattern.codepoints[pp + 2] and pattern.codepoints[pp + 2] ~= 0x5d then -- '-' followed by another char (not ']'), it's a range
|
||
for i = c, pattern.codepoints[pp + 2] do
|
||
cs[i] = 1
|
||
end
|
||
pp = pp + 3
|
||
elseif not c then -- Should never get here, but Just In Case...
|
||
error( 'Missing close-bracket', 3 )
|
||
else
|
||
cs[c] = 1
|
||
pp = pp + 1
|
||
end
|
||
first = false
|
||
end
|
||
|
||
local ret
|
||
if not csrefs[2] then
|
||
if not invert then
|
||
-- If there's only the one charset table, we can use it directly
|
||
ret = cs
|
||
else
|
||
-- Simple invert
|
||
ret = {}
|
||
setmetatable( ret, { __index = function ( t, k ) return k and not cs[k] end } )
|
||
end
|
||
else
|
||
-- Ok, we have to iterate over multiple charset tables
|
||
ret = {}
|
||
setmetatable( ret, { __index = function ( t, k )
|
||
if not k then
|
||
return nil
|
||
end
|
||
for i = 1, #csrefs do
|
||
if csrefs[i][k] then
|
||
return not invert
|
||
end
|
||
end
|
||
return invert
|
||
end } )
|
||
end
|
||
|
||
charset_cache[key] = { pp - p0, ret }
|
||
return pp, ret
|
||
end
|
||
|
||
-- Match a character set table with optional quantifier, followed by
|
||
-- the rest of the pattern.
|
||
-- Returns same as 'match' above.
|
||
match_charset = function ( sp, pp, charset )
|
||
local q = pattern.codepoints[pp]
|
||
if q == 0x2a then -- '*', 0 or more matches
|
||
pp = pp + 1
|
||
local i = 0
|
||
while charset[cps.codepoints[sp + i]] do
|
||
i = i + 1
|
||
end
|
||
while i >= 0 do
|
||
local ret = match( sp + i, pp )
|
||
if ret then
|
||
return ret
|
||
end
|
||
i = i - 1
|
||
end
|
||
return nil
|
||
elseif q == 0x2b then -- '+', 1 or more matches
|
||
pp = pp + 1
|
||
local i = 0
|
||
while charset[cps.codepoints[sp + i]] do
|
||
i = i + 1
|
||
end
|
||
while i > 0 do
|
||
local ret = match( sp + i, pp )
|
||
if ret then
|
||
return ret
|
||
end
|
||
i = i - 1
|
||
end
|
||
return nil
|
||
elseif q == 0x2d then -- '-', 0 or more matches non-greedy
|
||
pp = pp + 1
|
||
while true do
|
||
local ret = match( sp, pp )
|
||
if ret then
|
||
return ret
|
||
end
|
||
if not charset[cps.codepoints[sp]] then
|
||
return nil
|
||
end
|
||
sp = sp + 1
|
||
end
|
||
elseif q == 0x3f then -- '?', 0 or 1 match
|
||
pp = pp + 1
|
||
if charset[cps.codepoints[sp]] then
|
||
local ret = match( sp + 1, pp )
|
||
if ret then
|
||
return ret
|
||
end
|
||
end
|
||
return match( sp, pp )
|
||
else -- no suffix, must match 1
|
||
if charset[cps.codepoints[sp]] then
|
||
return match( sp + 1, pp )
|
||
else
|
||
return nil
|
||
end
|
||
end
|
||
end
|
||
|
||
init = init or 1
|
||
if init < 0 then
|
||
init = cps.len + init + 1
|
||
end
|
||
init = math.max( 1, math.min( init, cps.len + 1 ) )
|
||
|
||
-- Here is the actual match loop. It just calls 'match' on successive
|
||
-- starting positions (or not, if the pattern is anchored) until it finds a
|
||
-- match.
|
||
local sp = init
|
||
local pp = 1
|
||
if not noAnchor and pattern.codepoints[1] == 0x5e then -- '^': Pattern is anchored
|
||
anchor = true
|
||
pp = 2
|
||
end
|
||
|
||
repeat
|
||
ncapt, captures = 0, {}
|
||
local ep = match( sp, pp )
|
||
if ep then
|
||
for i = 1, ncapt do
|
||
captures[i] = getcapt( i, 'Unclosed capture beginning at pattern character ' .. captparen[i], 2 )
|
||
end
|
||
return sp, ep - 1, unpack( captures )
|
||
end
|
||
sp = sp + 1
|
||
until anchor or sp > cps.len + 1
|
||
return nil
|
||
end
|
||
|
||
-- Private function to decide if a pattern looks simple enough to use
|
||
-- Lua's built-in string library. The following make a pattern not simple:
|
||
-- * If it contains any bytes over 0x7f. We could skip these if they're not
|
||
-- inside brackets and aren't followed by quantifiers and aren't part of a
|
||
-- '%b', but that's too complicated to check.
|
||
-- * If it contains a negated character set.
|
||
-- * If it contains "%a" or any of the other %-prefixed character sets except %z.
|
||
-- * If it contains a '.' not followed by '*', '+', '-'. A bare '.' or '.?'
|
||
-- matches a partial UTF-8 character, but the others will happily enough
|
||
-- match a whole UTF-8 character thinking it's 2, 3 or 4.
|
||
-- * If it contains position-captures.
|
||
-- * If it matches the empty string
|
||
--
|
||
-- @param string pattern
|
||
-- @return boolean
|
||
local function patternIsSimple( pattern )
|
||
local findWithPcall = function ( ... )
|
||
local ok, ret = pcall( S.find, ... )
|
||
return ok and ret
|
||
end
|
||
|
||
return not (
|
||
S.find( pattern, '[\128-\255]' ) or
|
||
S.find( pattern, '%[%^' ) or
|
||
S.find( pattern, '%%[acdlpsuwxACDLPSUWXZ]' ) or
|
||
S.find( pattern, '%.[^*+-]' ) or S.find( pattern, '%.$' ) or
|
||
S.find( pattern, '()', 1, true ) or
|
||
pattern == '' or findWithPcall( '', pattern )
|
||
)
|
||
end
|
||
|
||
-- Find a pattern in a string
|
||
--
|
||
-- This works just like string.find, with the following changes:
|
||
-- * Everything works on UTF-8 characters rather than bytes
|
||
-- * Character classes are redefined in terms of Unicode properties:
|
||
-- * %a - Letter
|
||
-- * %c - Control
|
||
-- * %d - Decimal Number
|
||
-- * %l - Lower case letter
|
||
-- * %p - Punctuation
|
||
-- * %s - Separator, plus HT, LF, FF, CR, and VT
|
||
-- * %u - Upper case letter
|
||
-- * %w - Letter or Decimal Number
|
||
-- * %x - [0-9A-Fa-f０-９Ａ-Ｆａ-ｆ]
|
||
--
|
||
-- @see string.find
|
||
-- @param s string
|
||
-- @param pattern string Pattern
|
||
-- @param init int Starting index
|
||
-- @param plain boolean Literal match, no pattern matching
|
||
-- @return int starting index of the match
|
||
-- @return int ending index of the match
|
||
-- @return string|int* captures
|
||
function ustring.find( s, pattern, init, plain )
|
||
checkString( 'find', s )
|
||
checkPattern( 'find', pattern )
|
||
checkType( 'find', 3, init, 'number', true )
|
||
checkType( 'find', 4, plain, 'boolean', true )
|
||
local cps = utf8_explode( s )
|
||
if cps == nil then
|
||
error( "bad argument #1 for 'find' (string is not UTF-8)", 2 )
|
||
end
|
||
local pat = utf8_explode( pattern )
|
||
if pat == nil then
|
||
error( "bad argument #2 for 'find' (string is not UTF-8)", 2 )
|
||
end
|
||
|
||
if plain or patternIsSimple( pattern ) then
|
||
if init and init > cps.len + 1 then
|
||
init = cps.len + 1
|
||
end
|
||
local m
|
||
if plain then
|
||
m = { true, S.find( s, pattern, cps.bytepos[init], plain ) }
|
||
else
|
||
m = { pcall( S.find, s, pattern, cps.bytepos[init], plain ) }
|
||
end
|
||
if m[1] then
|
||
if m[2] then
|
||
m[2] = cpoffset( cps, m[2] )
|
||
m[3] = cpoffset( cps, m[3] )
|
||
end
|
||
return unpack( m, 2 )
|
||
end
|
||
end
|
||
|
||
return find( s, cps, pattern, pat, init )
|
||
end
|
||
|
||
-- Match a string against a pattern
|
||
--
|
||
-- @see ustring.find
|
||
-- @see string.match
|
||
-- @param s string
|
||
-- @param pattern string
|
||
-- @param init int Starting offset for match
|
||
-- @return string|int* captures, or the whole match if there are none
|
||
function ustring.match( s, pattern, init )
|
||
checkString( 'match', s )
|
||
checkPattern( 'match', pattern )
|
||
checkType( 'match', 3, init, 'number', true )
|
||
local cps = utf8_explode( s )
|
||
if cps == nil then
|
||
error( "bad argument #1 for 'match' (string is not UTF-8)", 2 )
|
||
end
|
||
local pat = utf8_explode( pattern )
|
||
if pat == nil then
|
||
error( "bad argument #2 for 'match' (string is not UTF-8)", 2 )
|
||
end
|
||
|
||
if patternIsSimple( pattern ) then
|
||
local ret = { pcall( S.match, s, pattern, cps.bytepos[init] ) }
|
||
if ret[1] then
|
||
return unpack( ret, 2 )
|
||
end
|
||
end
|
||
|
||
local m = { find( s, cps, pattern, pat, init ) }
|
||
if not m[1] then
|
||
return nil
|
||
end
|
||
if m[3] then
|
||
return unpack( m, 3 )
|
||
end
|
||
return sub( s, cps, m[1], m[2] )
|
||
end
|
||
|
||
-- Return an iterator function over the matches for a pattern
|
||
--
|
||
-- @see ustring.find
|
||
-- @see string.gmatch
|
||
-- @param s string
|
||
-- @param pattern string
|
||
-- @return function
|
||
-- @return nil
|
||
-- @return nil
|
||
function ustring.gmatch( s, pattern )
|
||
checkString( 'gmatch', s )
|
||
checkPattern( 'gmatch', pattern )
|
||
if patternIsSimple( pattern ) then
|
||
local ret = { pcall( S.gmatch, s, pattern ) }
|
||
if ret[1] then
|
||
return unpack( ret, 2 )
|
||
end
|
||
end
|
||
|
||
local cps = utf8_explode( s )
|
||
if cps == nil then
|
||
error( "bad argument #1 for 'gmatch' (string is not UTF-8)", 2 )
|
||
end
|
||
local pat = utf8_explode( pattern )
|
||
if pat == nil then
|
||
error( "bad argument #2 for 'gmatch' (string is not UTF-8)", 2 )
|
||
end
|
||
local init = 1
|
||
|
||
return function ()
|
||
local m = { find( s, cps, pattern, pat, init, true ) }
|
||
if not m[1] then
|
||
return nil
|
||
end
|
||
init = m[2] + 1
|
||
if m[3] then
|
||
return unpack( m, 3 )
|
||
end
|
||
return sub( s, cps, m[1], m[2] )
|
||
end
|
||
end
|
||
|
||
-- Replace pattern matches in a string
|
||
--
|
||
-- @see ustring.find
|
||
-- @see string.gsub
|
||
-- @param s string
|
||
-- @param pattern string
|
||
-- @param repl string|function|table
|
||
-- @param int n
|
||
-- @return string
|
||
-- @return int
|
||
function ustring.gsub( s, pattern, repl, n )
|
||
checkString( 'gsub', s )
|
||
checkPattern( 'gsub', pattern )
|
||
checkType( 'gsub', 4, n, 'number', true )
|
||
if patternIsSimple( pattern ) then
|
||
local ret = { pcall( S.gsub, s, pattern, repl, n ) }
|
||
if ret[1] then
|
||
return unpack( ret, 2 )
|
||
end
|
||
end
|
||
|
||
if n == nil then
|
||
n = 1e100
|
||
end
|
||
if n < 1 then
|
||
-- No replacement
|
||
return s, 0
|
||
end
|
||
|
||
local cps = utf8_explode( s )
|
||
if cps == nil then
|
||
error( "bad argument #1 for 'gsub' (string is not UTF-8)", 2 )
|
||
end
|
||
local pat = utf8_explode( pattern )
|
||
if pat == nil then
|
||
error( "bad argument #2 for 'gsub' (string is not UTF-8)", 2 )
|
||
end
|
||
|
||
if pat.codepoints[1] == 0x5e then -- '^': Pattern is anchored
|
||
-- There can be only the one match, so make that explicit
|
||
n = 1
|
||
end
|
||
|
||
local tp
|
||
if type( repl ) == 'function' then
|
||
tp = 1
|
||
elseif type( repl ) == 'table' then
|
||
tp = 2
|
||
elseif type( repl ) == 'string' then
|
||
tp = 3
|
||
elseif type( repl ) == 'number' then
|
||
repl = tostring( repl )
|
||
tp = 3
|
||
else
|
||
checkType( 'gsub', 3, repl, 'function or table or string' )
|
||
end
|
||
|
||
local init = 1
|
||
local ct = 0
|
||
local ret = {}
|
||
local zeroAdjustment = 0
|
||
repeat
|
||
local m = { find( s, cps, pattern, pat, init + zeroAdjustment ) }
|
||
if not m[1] then
|
||
break
|
||
end
|
||
if init < m[1] then
|
||
ret[#ret + 1] = sub( s, cps, init, m[1] - 1 )
|
||
end
|
||
local mm = sub( s, cps, m[1], m[2] )
|
||
|
||
-- This simplifies the code for the function and table cases (tp == 1 and tp == 2) when there are
|
||
-- no captures in the pattern. As documented it would be incorrect for the string case by making
|
||
-- %1 act like %0 instead of raising an "invalid capture index" error, but Lua in fact does
|
||
-- exactly that for string.gsub.
|
||
if #m < 3 then
|
||
m[3] = mm
|
||
end
|
||
|
||
local val, valType
|
||
if tp == 1 then
|
||
val = repl( unpack( m, 3 ) )
|
||
elseif tp == 2 then
|
||
val = repl[m[3]]
|
||
elseif tp == 3 then
|
||
if ct == 0 and #m < 11 then
|
||
local ss = S.gsub( repl, '%%[%%0-' .. ( #m - 2 ) .. ']', 'x' )
|
||
ss = S.match( ss, '%%[0-9]' )
|
||
if ss then
|
||
error( 'invalid capture index ' .. ss .. ' in replacement string', 2 )
|
||
end
|
||
end
|
||
local t = {
|
||
["%0"] = mm,
|
||
["%1"] = m[3],
|
||
["%2"] = m[4],
|
||
["%3"] = m[5],
|
||
["%4"] = m[6],
|
||
["%5"] = m[7],
|
||
["%6"] = m[8],
|
||
["%7"] = m[9],
|
||
["%8"] = m[10],
|
||
["%9"] = m[11],
|
||
["%%"] = "%"
|
||
}
|
||
val = S.gsub( repl, '%%[%%0-9]', t )
|
||
end
|
||
valType = type( val )
|
||
if valType ~= 'nil' and valType ~= 'string' and valType ~= 'number' then
|
||
error( 'invalid replacement value (a ' .. valType .. ')', 2 )
|
||
end
|
||
ret[#ret + 1] = val or mm
|
||
init = m[2] + 1
|
||
ct = ct + 1
|
||
zeroAdjustment = m[2] < m[1] and 1 or 0
|
||
until init > cps.len or ct >= n
|
||
if init <= cps.len then
|
||
ret[#ret + 1] = sub( s, cps, init, cps.len )
|
||
end
|
||
return table.concat( ret ), ct
|
||
end
|
||
|
||
---- Unicode Normalization ----
|
||
-- These functions load a conversion table when called
|
||
|
||
local function internalDecompose( cps, decomp )
|
||
local cp = {}
|
||
local normal = require 'ustring/normalization-data'
|
||
|
||
-- Decompose into cp, using the lookup table and logic for hangul
|
||
for i = 1, cps.len do
|
||
local c = cps.codepoints[i]
|
||
local m = decomp[c]
|
||
if m then
|
||
for j = 0, #m do
|
||
cp[#cp + 1] = m[j]
|
||
end
|
||
else
|
||
cp[#cp + 1] = c
|
||
end
|
||
end
|
||
|
||
-- Now sort combiners by class
|
||
local i, l = 1, #cp
|
||
while i < l do
|
||
local cc1 = normal.combclass[cp[i]]
|
||
local cc2 = normal.combclass[cp[i+1]]
|
||
if cc1 and cc2 and cc1 > cc2 then
|
||
cp[i], cp[i+1] = cp[i+1], cp[i]
|
||
if i > 1 then
|
||
i = i - 1
|
||
else
|
||
i = i + 1
|
||
end
|
||
else
|
||
i = i + 1
|
||
end
|
||
end
|
||
|
||
return cp, 1, l
|
||
end
|
||
|
||
local function internalCompose( cp, _, l )
|
||
local normal = require 'ustring/normalization-data'
|
||
|
||
-- Since NFD->NFC can never expand a character sequence, we can do this
|
||
-- in-place.
|
||
local comp = normal.comp[cp[1]]
|
||
local sc = 1
|
||
local j = 1
|
||
local lastclass = 0
|
||
for i = 2, l do
|
||
local c = cp[i]
|
||
local ccc = normal.combclass[c]
|
||
if ccc then
|
||
-- Trying a combiner with the starter
|
||
if comp and lastclass < ccc and comp[c] then
|
||
-- Yes!
|
||
c = comp[c]
|
||
cp[sc] = c
|
||
comp = normal.comp[c]
|
||
else
|
||
-- No, copy it to the right place for output
|
||
j = j + 1
|
||
cp[j] = c
|
||
lastclass = ccc
|
||
end
|
||
elseif comp and lastclass == 0 and comp[c] then
|
||
-- Combining two adjacent starters
|
||
c = comp[c]
|
||
cp[sc] = c
|
||
comp = normal.comp[c]
|
||
else
|
||
-- New starter, doesn't combine
|
||
j = j + 1
|
||
cp[j] = c
|
||
comp = normal.comp[c]
|
||
sc = j
|
||
lastclass = 0
|
||
end
|
||
end
|
||
|
||
return cp, 1, j
|
||
end
|
||
|
||
-- Normalize a string to NFC
|
||
--
|
||
-- Based on MediaWiki's UtfNormal class. Returns nil if the string is not valid
|
||
-- UTF-8.
|
||
--
|
||
-- @param s string
|
||
-- @return string|nil
|
||
function ustring.toNFC( s )
|
||
checkString( 'toNFC', s )
|
||
|
||
-- ASCII is always NFC
|
||
if not S.find( s, '[\128-\255]' ) then
|
||
return s
|
||
end
|
||
|
||
local cps = utf8_explode( s )
|
||
if cps == nil then
|
||
return nil
|
||
end
|
||
local normal = require 'ustring/normalization-data'
|
||
|
||
-- First, scan through to see if the string is definitely already NFC
|
||
local ok = true
|
||
for i = 1, cps.len do
|
||
local c = cps.codepoints[i]
|
||
if normal.check[c] then
|
||
ok = false
|
||
break
|
||
end
|
||
end
|
||
if ok then
|
||
return s
|
||
end
|
||
|
||
-- Next, expand to NFD then recompose
|
||
return internalChar( internalCompose( internalDecompose( cps, normal.decomp ) ) )
|
||
end
|
||
|
||
-- Normalize a string to NFD
|
||
--
|
||
-- Based on MediaWiki's UtfNormal class. Returns nil if the string is not valid
|
||
-- UTF-8.
|
||
--
|
||
-- @param s string
|
||
-- @return string|nil
|
||
function ustring.toNFD( s )
|
||
checkString( 'toNFD', s )
|
||
|
||
-- ASCII is always NFD
|
||
if not S.find( s, '[\128-\255]' ) then
|
||
return s
|
||
end
|
||
|
||
local cps = utf8_explode( s )
|
||
if cps == nil then
|
||
return nil
|
||
end
|
||
|
||
local normal = require 'ustring/normalization-data'
|
||
return internalChar( internalDecompose( cps, normal.decomp ) )
|
||
end
|
||
|
||
-- Normalize a string to NFKC
|
||
--
|
||
-- Based on MediaWiki's UtfNormal class. Returns nil if the string is not valid
|
||
-- UTF-8.
|
||
--
|
||
-- @param s string
|
||
-- @return string|nil
|
||
function ustring.toNFKC( s )
|
||
checkString( 'toNFKC', s )
|
||
|
||
-- ASCII is always NFKC
|
||
if not S.find( s, '[\128-\255]' ) then
|
||
return s
|
||
end
|
||
|
||
local cps = utf8_explode( s )
|
||
if cps == nil then
|
||
return nil
|
||
end
|
||
local normal = require 'ustring/normalization-data'
|
||
|
||
-- Next, expand to NFKD then recompose
|
||
return internalChar( internalCompose( internalDecompose( cps, normal.decompK ) ) )
|
||
end
|
||
|
||
-- Normalize a string to NFKD
|
||
--
|
||
-- Based on MediaWiki's UtfNormal class. Returns nil if the string is not valid
|
||
-- UTF-8.
|
||
--
|
||
-- @param s string
|
||
-- @return string|nil
|
||
function ustring.toNFKD( s )
|
||
checkString( 'toNFKD', s )
|
||
|
||
-- ASCII is always NFKD
|
||
if not S.find( s, '[\128-\255]' ) then
|
||
return s
|
||
end
|
||
|
||
local cps = utf8_explode( s )
|
||
if cps == nil then
|
||
return nil
|
||
end
|
||
|
||
local normal = require 'ustring/normalization-data'
|
||
return internalChar( internalDecompose( cps, normal.decompK ) )
|
||
end
|
||
|
||
return ustring
|