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. 48.Pp 49The preferred method of including other files and modules is with 50.Fn require name , 51such as: 52.Bd -literal 53-- License block 54 55config = require("config"); 56menu = require("menu"); 57password = require("password"); 58-- One blank line following the module require block 59.Ed 60.Pp 61.Fn include 62is generally avoided. 63.Pp 64Indentation and wrapping should match the guidelines provided by 65.Xr style 9 . 66Do note that it is ok to wrap much earlier than 80 columns if readability would 67otherwise suffer. 68.Pp 69Where possible, 70.Fn s:method ... 71is preferred to 72.Fn method s ... . 73This is applicable to objects with methods. 74String are a commonly-used example of objects with methods. 75.Pp 76Testing for 77.Va nil 78should be done explicitly, rather than as a boolean expression. 79Single-line conditional statements and loops should be avoided. 80.Pp 81.Ic local 82variables should be preferred to global variables in module scope. 83internal_underscores tend to be preferred for variable identifiers, while 84camelCase tends to be preferred for function identifiers. 85.Pp 86If a table definition spans multiple lines, then the final value in the table 87should include the optional terminating comma. 88For example: 89.Bd -literal 90-- No terminating comma needed for trivial table definitions 91local trivial_table = {1, 2, 3, 4} 92 93local complex_table = { 94 { 95 id = "foo", 96 func = foo_function, -- Trailing comma preferred 97 }, 98 { 99 id = "bar", 100 func = bar_function, 101 }, -- Trailing comma preferred 102} 103.Ed 104.Pp 105This reduces the chance for errors to be introduced when modifying more complex 106tables. 107.Pp 108Multiple local variables should not be declared 109.Sy and 110initialized on a single line. 111Lines containing multiple variable declarations without initialization are ok. 112Lines containing multiple variable declarations initialized to a single function 113call returning a tuple with the same number of values is also ok. 114.Pp 115Initialization 116.Sy should 117be done at declaration time as appropriate. 118.Sh SEE ALSO 119.Xr style 9 120.Sh HISTORY 121This manual page is inspired from the same source as 122.Xr style 9 123manual page in 124.Fx . 125