1.\"- 2.\" SPDX-License-Identifier: BSD-2-Clause 3.\" 4.\" Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org> 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18.\" ARE DISCLAIMED. IN NO EVENT SHALL [your name] OR CONTRIBUTORS BE LIABLE 19.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.Dd February 25, 2018 28.Dt STYLE.LUA 9 29.Os 30.Sh NAME 31.Nm style.lua 32.Nd 33.Fx 34lua file style guide 35.Sh DESCRIPTION 36This file specifies the preferred style for lua source files in the 37.Fx 38source tree. 39Many of the style rules are implicit in the examples. 40Be careful to check the examples before assuming that 41.Nm 42is silent on an issue. 43.Pp 44The copyright header should be a series of single-line comments. 45Use the single-line comment style for every line in a multi-line comment. 46.Pp 47After any copyright header, there is a blank line, and the 48.Li $\&FreeBSD$ 49comment for non-C/C++ source files. 50.Pp 51The preferred method of including other files and modules is with 52.Fn require name , 53such as: 54.Bd -literal 55 56config = require("config"); 57menu = require("menu"); 58password = require("password"); 59-- One blank line following the module require block 60.Ed 61.Pp 62.Fn include 63is generally avoided. 64.Pp 65Indentation and wrapping should match the guidelines provided by 66.Xr style 9 . 67Do note that it is ok to wrap much earlier than 80 columns if readability would 68otherwise suffer. 69.Pp 70Where possible, 71.Fn s:method ... 72is preferred to 73.Fn method s ... . 74This is applicable to objects with methods. 75String are a commonly-used example of objects with methods. 76.Pp 77Testing for 78.Va nil 79should be done explicitly, rather than as a boolean expression. 80Single-line conditional statements and loops should be avoided. 81.Pp 82.Ic local 83variables should be preferred to global variables in module scope. 84internal_underscores tend to be preferred for variable identifiers, while 85camelCase tends to be preferred for function identifiers. 86.Pp 87If a table definition spans multiple lines, then the final value in the table 88should include the optional terminating comma. 89For example: 90.Bd -literal 91-- No terminating comma needed for trivial table definitions 92local trivial_table = {1, 2, 3, 4} 93 94local complex_table = { 95 { 96 id = "foo", 97 func = foo_function, -- Trailing comma preferred 98 }, 99 { 100 id = "bar", 101 func = bar_function, 102 }, -- Trailing comma preferred 103} 104.Ed 105.Pp 106This reduces the chance for errors to be introduced when modifying more complex 107tables. 108.Pp 109Multiple local variables should not be declared 110.Sy and 111initialized on a single line. 112Lines containing multiple variable declarations without initialization are ok. 113Lines containing multiple variable declarations initialized to a single function 114call returning a tuple with the same number of values is also ok. 115.Pp 116Initialization 117.Sy should 118be done at declaration time as appropriate. 119.Sh SEE ALSO 120.Xr style 9 121.Sh HISTORY 122This manual page is inspired from the same source as 123.Xr style 9 124manual page in 125.Fx . 126