Comparison

util.error: Add new util library for structured errors

comparison

equal deleted inserted replaced

-:0dbb285f903e
+:848fd204708c
+local error_mt = { __name = "error" };
+function error_mt:__tostring()
+	return ("error<%s:%s:%s>"):format(self.type, self.condition, self.text);
+end
+local function is_err(e)
+	return getmetatable(e) == error_mt;
+end
+local function new(e, context, registry)
+	local template = (registry and registry[e]) or e or {};
+	return setmetatable({
+		type = template.type or "cancel";
+		condition = template.condition or "undefined-condition";
+		text = template.text;
+		context = context or template.context or { _error_id = e };
+	}, error_mt);
+end
+local function coerce(ok, err, ...)
+	if ok or is_err(err) then
+		return ok, err, ...;
+	end
+	local new_err = setmetatable({
+		native = err;
+		type = "cancel";
+		condition = "undefined-condition";
+	}, error_mt);
+	return ok, new_err, ...;
+end
+return {
+	new = new;
+	coerce = coerce;
+	is_err = is_err;
+}