style.lua —
FreeBSD lua file style
guide
This file specifies the preferred style for lua source files in the
FreeBSD source tree. Many of the style rules are
implicit in the examples. Be careful to check the examples before assuming
that
style.lua is silent on an issue.
The copyright header should be a series of single-line comments. Use the
single-line comment style for every line in a multi-line comment.
After any copyright header, there is a blank line, and the
$FreeBSD$ comment for non-C/C++ source files.
The preferred method of including other files and modules is with
require(
name),
such as:
-- $FreeBSD: releng/12.2/share/man/man9/style.lua.9 333419 2018-05-09 16:52:28Z kevans $
config = require("config");
menu = require("menu");
password = require("password");
-- One blank line following the module require block
include() is generally avoided.
Indentation and wrapping should match the guidelines provided by
. Do note that it is ok to wrap much
earlier than 80 columns if readability would otherwise suffer.
Where possible,
s:method(
...) is
preferred to
method(
s,
...). This is applicable to objects with
methods. String are a commonly-used example of objects with methods.
Testing for
nil should be done explicitly,
rather than as a boolean expression. Single-line conditional statements and
loops should be avoided.
local variables should be preferred to global
variables in module scope. internal_underscores tend to be preferred for
variable identifiers, while camelCase tends to be preferred for function
identifiers.
If a table definition spans multiple lines, then the final value in the table
should include the optional terminating comma. For example:
-- No terminating comma needed for trivial table definitions
local trivial_table = {1, 2, 3, 4}
local complex_table = {
{
id = "foo",
func = foo_function, -- Trailing comma preferred
},
{
id = "bar",
func = bar_function,
}, -- Trailing comma preferred
}
This reduces the chance for errors to be introduced when modifying more complex
tables.
Multiple local variables should not be declared
and
initialized on a single line. Lines containing multiple variable declarations
without initialization are ok. Lines containing multiple variable declarations
initialized to a single function call returning a tuple with the same number
of values is also ok.
Initialization
should be done at declaration time
as appropriate.
This manual page is inspired from the same source as
manual page in
FreeBSD.