local enum ptr_error

	"invalid-table"

	"invalid-path"

end

local function unescape_token(escaped_token : string) : string

	local unescaped = escaped_token:gsub("~1", "/"):gsub("~0", "~")

	return unescaped

end

local function resolve_json_pointer(ref : table, path : string) : any, ptr_error

	local ptr_len = #path+1

	for part, pos in path:gmatch("/([^/]*)()") do

		local token = unescape_token(part)

		if not ref is table then

			return nil

		end

		local idx = next(ref)

		local new_ref : any

		if idx is string then

			new_ref = ref[token]

		elseif idx is integer then

			local i = tonumber(token)

			if token == "-" then i = #ref + 1 end

			new_ref = ref[i+1]

		else

			return nil, "invalid-table"

		end

		if pos as integer == ptr_len then

			return new_ref

		elseif new_ref is table then

			ref = new_ref

		elseif not ref is table then

			return nil, "invalid-path"

		end

	end

	return ref

end

return {

	resolve = resolve_json_pointer,

}