# The following bytes have significant meaning in JSON
const BACKSPACE      = UInt8('\b')
const TAB            = UInt8('\t')
const NEWLINE        = UInt8('\n')
const FORM_FEED      = UInt8('\f')
const RETURN         = UInt8('\r')
const SPACE          = UInt8(' ')
const STRING_DELIM   = UInt8('"')
const PLUS_SIGN      = UInt8('+')
const DELIMITER      = UInt8(',')
const MINUS_SIGN     = UInt8('-')
const DECIMAL_POINT  = UInt8('.')
const SOLIDUS        = UInt8('/')
const DIGIT_ZERO     = UInt8('0')
const DIGIT_NINE     = UInt8('9')
const SEPARATOR      = UInt8(':')
const LATIN_UPPER_A  = UInt8('A')
const LATIN_UPPER_E  = UInt8('E')
const LATIN_UPPER_F  = UInt8('F')
const LATIN_UPPER_I  = UInt8('I')
const LATIN_UPPER_N  = UInt8('N')
const ARRAY_BEGIN    = UInt8('[')
const BACKSLASH      = UInt8('\\')
const ARRAY_END      = UInt8(']')
const LATIN_A        = UInt8('a')
const LATIN_B        = UInt8('b')
const LATIN_E        = UInt8('e')
const LATIN_F        = UInt8('f')
const LATIN_I        = UInt8('i')
const LATIN_L        = UInt8('l')
const LATIN_N        = UInt8('n')
const LATIN_R        = UInt8('r')
const LATIN_S        = UInt8('s')
const LATIN_T        = UInt8('t')
const LATIN_U        = UInt8('u')
const LATIN_Y        = UInt8('y')
const OBJECT_BEGIN   = UInt8('{')
const OBJECT_END     = UInt8('}')

const ESCAPES = Dict(
    STRING_DELIM => STRING_DELIM,
    BACKSLASH    => BACKSLASH,
    SOLIDUS      => SOLIDUS,
    LATIN_B      => BACKSPACE,
    LATIN_F      => FORM_FEED,
    LATIN_N      => NEWLINE,
    LATIN_R      => RETURN,
    LATIN_T      => TAB)

const REVERSE_ESCAPES = Dict(reverse(p) for p in ESCAPES)
const ESCAPED_ARRAY = Vector{Vector{UInt8}}(undef, 256)
for c in 0x00:0xFF
    ESCAPED_ARRAY[c + 1] = if c == SOLIDUS
        [SOLIDUS]  # don't escape this one
    elseif c ≥ 0x80
        [c]  # UTF-8 character copied verbatim
    elseif haskey(REVERSE_ESCAPES, c)
        [BACKSLASH, REVERSE_ESCAPES[c]]
    elseif iscntrl(Char(c)) || !isprint(Char(c))
        UInt8[BACKSLASH, LATIN_U, string(c, base=16, pad=4)...]
    else
        [c]
    end
end

export BACKSPACE, TAB, NEWLINE, FORM_FEED, RETURN, SPACE, STRING_DELIM,
       PLUS_SIGN, DELIMITER, MINUS_SIGN, DECIMAL_POINT, SOLIDUS, DIGIT_ZERO,
       DIGIT_NINE, SEPARATOR, LATIN_UPPER_A, LATIN_UPPER_E, LATIN_UPPER_F,
       LATIN_UPPER_I, LATIN_UPPER_N, ARRAY_BEGIN, BACKSLASH, ARRAY_END,
       LATIN_A, LATIN_B, LATIN_E, LATIN_F, LATIN_I, LATIN_L, LATIN_N, LATIN_R,
       LATIN_S, LATIN_T, LATIN_U, LATIN_Y, OBJECT_BEGIN, OBJECT_END, ESCAPES,
       REVERSE_ESCAPES, ESCAPED_ARRAY