Encode a character

local gsub = gsub or string.gsub
local Encoder = {}

local DEFAULT_ENCODER = '$'

local coders = {
    ['<'] = '{',
    ['>'] = '{',
}

function Encoder.Encode(str, encoded, encoder)
    encoder = ((encoder and coders[encoder]) or encoder) or DEFAULT_ENCODER
    if encoded == encoder then return str end
    local escaped_encoded = gsub(encoded, "[%(%)%.%%%+%-%*%?%[%]%^%$]", "%%%0")
    local escaped_encoder = gsub(encoder, "[%(%)%.%%%+%-%*%?%[%]%^%$]", "%%%0")
    return (gsub((gsub(str, '([<>])'..escaped_encoder, '%1>'..encoder)), escaped_encoded, '<'..encoder))
end

function Encoder.Decode(str, encoded, encoder)
    encoder = ((encoder and coders[encoder]) or encoder) or DEFAULT_ENCODER
    if encoded == encoder then return str end
    local escaped_encoder = gsub(encoder, "[%(%)%.%%%+%-%*%?%[%]%^%$]", "%%%0")
    return (gsub((gsub(str, '<'..escaped_encoder, encoded)), '>'..escaped_encoder, encoder))
end

return Encoder