utf8pascal.pas

// Stolen from http://bjoern.hoehrmann.de/utf-8/decoder/dfa/
const UTF8_ACCEPT=0;
const UTF8_REJECT=1;

const utf8d: array[0..399] of Byte = (
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 00..1f
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 20..3f
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 40..5f
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 60..7f
  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, // 80..9f
  7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, // a0..bf
  8,8,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, // c0..df
  $a,$3,$3,$3,$3,$3,$3,$3,$3,$3,$3,$3,$3,$4,$3,$3, // e0..ef
  $b,$6,$6,$6,$5,$8,$8,$8,$8,$8,$8,$8,$8,$8,$8,$8, // f0..ff
  $0,$1,$2,$3,$5,$8,$7,$1,$1,$1,$4,$6,$1,$1,$1,$1, // s0..s0
  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,0,1,0,1,1,1,1,1,1, // s1..s2
  1,2,1,1,1,1,1,2,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1, // s3..s4
  1,2,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,3,1,3,1,1,1,1,1,1, // s5..s6
  1,3,1,1,1,1,1,3,1,3,1,1,1,1,1,1,1,3,1,1,1,1,1,1,1,1,1,1,1,1,1,1  // s7..s8
);

type PLongword = ^Longword;

function UTF8Decode(State: PLongword; Codep: PLongword; By: Longword): Longword;
var
  Tp: Longword;
begin
  Tp := utf8d[By];

  if state^ <> UTF8_ACCEPT then
    codep^ := (By and cardinal($3f){u}) or (codep^ shl 6)
  else
    codep^ := ($ff shr Tp) and (By);

  state^ := utf8d[256 + (state^ * 16) + Tp];
  exit(state^);
end;