File

+
−
+
−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]
+
−		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,
+
−}