type

T1ByteChar char():assert[(@>0)and(@<0x80)]
T2ByteChar array[2]of Byte:assert[((@[0]and 0xE0)=0xC0)
  and((@[1]and 0xC0)=0x80)]:displ=(HEX((@[0]and 0x1F)shl 6+(@[1]and 0x3F)))
T3ByteChar array[3]of Byte:assert[((@[0]and 0xF0)=0xE0)
  and((@[1]and 0xC0)=0x80)and((@[2]and 0xC0)=0x80)]:displ=(HEX((@[0]and 0x0F)shl 12
  +(@[1]and 0x3F)shl 6+(@[2]and 0x3F)))

TUtf8Char try
  B1: T1ByteChar
  B2: T2ByteChar
  B3: T3ByteChar
  X: Byte
endt

TUtf8Array(Sz) array of TUtf8Char:[@:Size=@:Sz]:displ=(
  '"',ShowArray(@,(WCHR(@.B1 exc(
    ((@.B2[0]and 0x1F)shl 6+(@.B2[1]and 0x3F)) exc(
    ((@.B3[0]and 0x0F)shl 12+(@.B3[1]and 0x3F)shl 6+(@.B3[2]and 0x3F)) exc
    @.X))))),'"')

Other specifications.

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