author | Kim Alvefur <zash@zash.se> |
Thu, 20 Oct 2022 16:50:12 +0200 | |
changeset 12786 | 8815d3090928 |
parent 12391 | 05c250fa335a |
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# Prosody Coding Style Guide |
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This style guides lists the coding conventions used in the |
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[Prosody](https://prosody.im/) project. It is based heavily on the [style guide used by the LuaRocks project](https://github.com/luarocks/lua-style-guide). |
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## Indentation and formatting |
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* Prosody code is indented with tabs at the start of the line, a single |
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tab per logical indent level: |
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|
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```lua |
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for i, pkg in ipairs(packages) do |
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for name, version in pairs(pkg) do |
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if name == searched then |
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print(version); |
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end |
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end |
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end |
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``` |
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Tab width is configurable in editors, so never assume a particular width. |
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Specifically this means you should not mix tabs and spaces, or use tabs for |
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alignment of items at different indentation levels. |
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* Use LF (Unix) line endings. |
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## Comments |
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* Comments are encouraged where necessary to explain non-obvious code. |
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* In general comments should be used to explain 'why', not 'how' |
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### Comment tags |
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A comment may be prefixed with one of the following tags: |
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* **FIXME**: Indicates a serious problem with the code that should be addressed |
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* **TODO**: Indicates an open task, feature request or code restructuring that |
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is primarily of interest to developers (otherwise it should be in the |
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issue tracker). |
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* **COMPAT**: Must be used on all code that is present only for backwards-compatibility, |
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and may be removed one day. For example code that is added to support old |
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or buggy third-party software or dependencies. |
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**Example:** |
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```lua |
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-- TODO: implement method |
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local function something() |
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-- FIXME: check conditions |
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end |
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``` |
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## Variable names |
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* Variable names with larger scope should be more descriptive than those with |
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smaller scope. One-letter variable names should be avoided except for very |
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small scopes (less than ten lines) or for iterators. |
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* `i` should be used only as a counter variable in for loops (either numeric for |
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or `ipairs`). |
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* Prefer more descriptive names than `k` and `v` when iterating with `pairs`, |
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unless you are writing a function that operates on generic tables. |
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* Use `_` for ignored variables (e.g. in for loops:) |
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```lua |
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for _, item in ipairs(items) do |
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do_something_with_item(item); |
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end |
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``` |
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* Generally all identifiers (variables and function names) should use `snake_case`, |
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i.e. lowercase words joined by `_`. |
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```lua |
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-- bad |
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local OBJEcttsssss = {} |
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local thisIsMyObject = {} |
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local c = function() |
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-- ...stuff... |
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end |
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-- good |
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local this_is_my_object = {}; |
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local function do_that_thing() |
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-- ...stuff... |
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end |
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``` |
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> **Rationale:** The standard library uses lowercase APIs, with `joinedlowercase` |
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names, but this does not scale too well for more complex APIs. `snake_case` |
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tends to look good enough and not too out-of-place along side the standard |
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APIs. |
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```lua |
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for _, name in pairs(names) do |
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-- ...stuff... |
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end |
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``` |
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* Prefer using `is_` when naming boolean functions: |
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```lua |
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-- bad |
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local function evil(alignment) |
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return alignment < 100 |
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end |
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|
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-- good |
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local function is_evil(alignment) |
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return alignment < 100; |
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end |
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``` |
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* `UPPER_CASE` is to be used sparingly, with "constants" only. |
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|
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> **Rationale:** "Sparingly", since Lua does not have real constants. This |
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notation is most useful in libraries that bind C libraries, when bringing over |
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constants from C. |
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|
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* Do not use uppercase names starting with `_`, they are reserved by Lua. |
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|
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## Tables |
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|
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* When creating a table, prefer populating its fields all at once, if possible: |
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|
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```lua |
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local player = { name = "Jack", class = "Rogue" }; |
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``` |
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|
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* Items should be separated by commas. If there are many items, put each |
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key/value on a separate line and use a semi-colon after each item (including |
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the last one): |
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139 |
|
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```lua |
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141 |
local player = { |
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name = "Jack"; |
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class = "Rogue"; |
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} |
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``` |
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> **Rationale:** This makes the structure of your tables more evident at a glance. |
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Trailing semi-colons make it quicker to add new fields and produces shorter diffs. |
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|
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* Use plain `key` syntax whenever possible, use `["key"]` syntax when using names |
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that can't be represented as identifiers and avoid mixing representations in |
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a declaration: |
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|
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```lua |
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local mytable = { |
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["1394-E"] = val1; |
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["UTF-8"] = val2; |
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["and"] = val2; |
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} |
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``` |
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|
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## Strings |
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|
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* Use `"double quotes"` for strings; use `'single quotes'` when writing strings |
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that contain double quotes. |
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|
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```lua |
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local name = "Prosody"; |
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local sentence = 'The name of the program is "Prosody"'; |
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``` |
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|
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> **Rationale:** Double quotes are used as string delimiters in a larger number of |
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programming languages. Single quotes are useful for avoiding escaping when |
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using double quotes in literals. |
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|
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## Line lengths |
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|
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* There are no hard or soft limits on line lengths. Line lengths are naturally |
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limited by using one statement per line. If that still produces lines that are |
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too long (e.g. an expression that produces a line over 256-characters long, |
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for example), this means the expression is too complex and would do better |
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split into subexpressions with reasonable names. |
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|
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> **Rationale:** No one works on VT100 terminals anymore. If line lengths are a proxy |
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for code complexity, we should address code complexity instead of using line |
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breaks to fit mind-bending statements over multiple lines. |
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|
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## Function declaration syntax |
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|
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* Prefer function syntax over variable syntax. This helps differentiate between |
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named and anonymous functions. |
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|
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```lua |
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-- bad |
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local nope = function(name, options) |
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-- ...stuff... |
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197 |
end |
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|
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-- good |
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local function yup(name, options) |
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-- ...stuff... |
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end |
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``` |
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|
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* Perform validation early and return as early as possible. |
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|
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```lua |
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-- bad |
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local function is_good_name(name, options, arg) |
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local is_good = #name > 3 |
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is_good = is_good and #name < 30 |
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|
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-- ...stuff... |
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|
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return is_good |
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end |
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|
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-- good |
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local function is_good_name(name, options, args) |
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if #name < 3 or #name > 30 then |
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return false; |
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end |
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|
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-- ...stuff... |
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|
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return true; |
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end |
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``` |
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|
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## Function calls |
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|
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* Even though Lua allows it, generally you should not omit parentheses |
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for functions that take a unique string literal argument. |
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|
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```lua |
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-- bad |
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local data = get_data"KRP"..tostring(area_number) |
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-- good |
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local data = get_data("KRP"..tostring(area_number)); |
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local data = get_data("KRP")..tostring(area_number); |
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``` |
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|
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> **Rationale:** It is not obvious at a glace what the precedence rules are |
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when omitting the parentheses in a function call. Can you quickly tell which |
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of the two "good" examples in equivalent to the "bad" one? (It's the second |
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one). |
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|
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* You should not omit parenthesis for functions that take a unique table |
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argument on a single line. You may do so for table arguments that span several |
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lines. |
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|
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```lua |
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local an_instance = a_module.new { |
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a_parameter = 42; |
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another_parameter = "yay"; |
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} |
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``` |
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|
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> **Rationale:** The use as in `a_module.new` above occurs alone in a statement, |
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so there are no precedence issues. |
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|
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## Table attributes |
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|
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* Use dot notation when accessing known properties. |
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|
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```lua |
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local luke = { |
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jedi = true; |
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age = 28; |
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} |
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|
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-- bad |
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local is_jedi = luke["jedi"] |
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|
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-- good |
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local is_jedi = luke.jedi; |
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``` |
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|
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* Use subscript notation `[]` when accessing properties with a variable or if using a table as a list. |
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|
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```lua |
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local vehicles = load_vehicles_from_disk("vehicles.dat") |
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|
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if vehicles["Porsche"] then |
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porsche_handler(vehicles["Porsche"]); |
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vehicles["Porsche"] = nil; |
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end |
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for name, cars in pairs(vehicles) do |
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regular_handler(cars); |
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end |
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``` |
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|
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> **Rationale:** Using dot notation makes it clearer that the given key is meant |
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to be used as a record/object field. |
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|
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## Functions in tables |
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|
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* When declaring modules and classes, declare functions external to the table definition: |
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|
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```lua |
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local my_module = {}; |
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|
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function my_module.a_function(x) |
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-- code |
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end |
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``` |
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|
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* When declaring metatables, declare function internal to the table definition. |
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|
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```lua |
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local version_mt = { |
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__eq = function(a, b) |
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-- code |
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end; |
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__lt = function(a, b) |
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-- code |
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end; |
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} |
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``` |
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|
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> **Rationale:** Metatables contain special behavior that affect the tables |
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they're assigned (and are used implicitly at the call site), so it's good to |
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be able to get a view of the complete behavior of the metatable at a glance. |
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|
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This is not as important for objects and modules, which usually have way more |
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code, and which don't fit in a single screen anyway, so nesting them inside |
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the table does not gain much: when scrolling a longer file, it is more evident |
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that `check_version` is a method of `Api` if it says `function Api:check_version()` |
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than if it says `check_version = function()` under some indentation level. |
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|
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## Variable declaration |
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|
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* Always use `local` to declare variables. |
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|
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```lua |
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-- bad |
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superpower = get_superpower() |
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|
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-- good |
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local superpower = get_superpower(); |
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``` |
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|
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> **Rationale:** Not doing so will result in global variables to avoid polluting |
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the global namespace. |
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|
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## Variable scope |
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|
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* Assign variables with the smallest possible scope. |
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|
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350 |
```lua |
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351 |
-- bad |
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local function good() |
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local name = get_name() |
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|
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test() |
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print("doing stuff..") |
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|
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--...other stuff... |
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|
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if name == "test" then |
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parents:
diff
changeset
|
361 |
return false |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
362 |
end |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
363 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
364 |
return name |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
365 |
end |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
366 |
|
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
367 |
-- good |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
368 |
local bad = function() |
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|
369 |
test(); |
3a7f822f6edd
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|
370 |
print("doing stuff.."); |
9862
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parents:
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changeset
|
371 |
|
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
372 |
--...other stuff... |
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parents:
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changeset
|
373 |
|
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marc0s <marcos@tenak.net>
parents:
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|
374 |
local name = get_name(); |
9862
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parents:
diff
changeset
|
375 |
|
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
376 |
if name == "test" then |
9943
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doc/coding_style: apply consistent semi-colon usage
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parents:
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|
377 |
return false; |
9862
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parents:
diff
changeset
|
378 |
end |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
379 |
|
9943
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marc0s <marcos@tenak.net>
parents:
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changeset
|
380 |
return name; |
9862
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parents:
diff
changeset
|
381 |
end |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
382 |
``` |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
383 |
|
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
384 |
> **Rationale:** Lua has proper lexical scoping. Declaring the function later means that its |
54147de1d1b1
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parents:
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|
385 |
scope is smaller, so this makes it easier to check for the effects of a variable. |
54147de1d1b1
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parents:
diff
changeset
|
386 |
|
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
387 |
## Conditional expressions |
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
388 |
|
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
389 |
* False and nil are falsy in conditional expressions. Use shortcuts when you |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
390 |
can, unless you need to know the difference between false and nil. |
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
391 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
392 |
```lua |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
393 |
-- bad |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
394 |
if name ~= nil then |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
395 |
-- ...stuff... |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
396 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
397 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
398 |
-- good |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
399 |
if name then |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
400 |
-- ...stuff... |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
401 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
402 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
403 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
404 |
* Avoid designing APIs which depend on the difference between `nil` and `false`. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
405 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
406 |
* Use the `and`/`or` idiom for the pseudo-ternary operator when it results in |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
407 |
more straightforward code. When nesting expressions, use parentheses to make it |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
408 |
easier to scan visually: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
409 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
410 |
```lua |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
411 |
local function default_name(name) |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
412 |
-- return the default "Waldo" if name is nil |
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parents:
9904
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changeset
|
413 |
return name or "Waldo"; |
9862
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parents:
diff
changeset
|
414 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
415 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
416 |
local function brew_coffee(machine) |
9943
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marc0s <marcos@tenak.net>
parents:
9904
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changeset
|
417 |
return (machine and machine.is_loaded) and "coffee brewing" or "fill your water"; |
9862
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parents:
diff
changeset
|
418 |
end |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
419 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
420 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
421 |
Note that the `x and y or z` as a substitute for `x ? y : z` does not work if |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
422 |
`y` may be `nil` or `false` so avoid it altogether for returning booleans or |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
423 |
values which may be nil. |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
424 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
425 |
## Blocks |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
426 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
427 |
* Use single-line blocks only for `then return`, `then break` and `function return` (a.k.a "lambda") constructs: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
428 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
429 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
430 |
-- good |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
431 |
if test then break end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
432 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
433 |
-- good |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
434 |
if not ok then return nil, "this failed for this reason: " .. reason end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
435 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
436 |
-- good |
9943
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doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
437 |
use_callback(x, function(k) return k.last end); |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
438 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
439 |
-- good |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
440 |
if test then |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
441 |
return false |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
442 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
443 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
444 |
-- bad |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
445 |
if test < 1 and do_complicated_function(test) == false or seven == 8 and nine == 10 then do_other_complicated_function() end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
446 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
447 |
-- good |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
448 |
if test < 1 and do_complicated_function(test) == false or seven == 8 and nine == 10 then |
9943
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
449 |
do_other_complicated_function(); |
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
450 |
return false; |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
451 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
452 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
453 |
|
9904
f2104b36f673
doc/coding_style: The codebase uses semicolons
Kim Alvefur <zash@zash.se>
parents:
9903
diff
changeset
|
454 |
* Separate statements onto multiple lines. Use semicolons as statement terminators. |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
455 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
456 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
457 |
-- bad |
9904
f2104b36f673
doc/coding_style: The codebase uses semicolons
Kim Alvefur <zash@zash.se>
parents:
9903
diff
changeset
|
458 |
local whatever = "sure" |
f2104b36f673
doc/coding_style: The codebase uses semicolons
Kim Alvefur <zash@zash.se>
parents:
9903
diff
changeset
|
459 |
a = 1 b = 2 |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
460 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
461 |
-- good |
9904
f2104b36f673
doc/coding_style: The codebase uses semicolons
Kim Alvefur <zash@zash.se>
parents:
9903
diff
changeset
|
462 |
local whatever = "sure"; |
f2104b36f673
doc/coding_style: The codebase uses semicolons
Kim Alvefur <zash@zash.se>
parents:
9903
diff
changeset
|
463 |
a = 1; |
f2104b36f673
doc/coding_style: The codebase uses semicolons
Kim Alvefur <zash@zash.se>
parents:
9903
diff
changeset
|
464 |
b = 2; |
9862
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
465 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
466 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
467 |
## Spacing |
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
468 |
|
9903
8c831c76fc94
doc/coding_style: Trim trailing whitespace
Kim Alvefur <zash@zash.se>
parents:
9902
diff
changeset
|
469 |
* Use a space after `--`. |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
470 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
471 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
472 |
--bad |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
473 |
-- good |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
474 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
475 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
476 |
* Always put a space after commas and between operators and assignment signs: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
477 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
478 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
479 |
-- bad |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
480 |
local x = y*9 |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
481 |
local numbers={1,2,3} |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
482 |
numbers={1 , 2 , 3} |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
483 |
numbers={1 ,2 ,3} |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
484 |
local strings = { "hello" |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
485 |
, "Lua" |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
486 |
, "world" |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
487 |
} |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
488 |
dog.set( "attr",{ |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
489 |
age="1 year", |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
490 |
breed="Bernese Mountain Dog" |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
491 |
}) |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
492 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
493 |
-- good |
9943
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
494 |
local x = y * 9; |
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
495 |
local numbers = {1, 2, 3}; |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
496 |
local strings = { |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
497 |
"hello"; |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
498 |
"Lua"; |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
499 |
"world"; |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
500 |
} |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
501 |
dog.set("attr", { |
9943
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
502 |
age = "1 year"; |
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
503 |
breed = "Bernese Mountain Dog"; |
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
504 |
}); |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
505 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
506 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
507 |
* Indent tables and functions according to the start of the line, not the construct: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
508 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
509 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
510 |
-- bad |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
511 |
local my_table = { |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
512 |
"hello", |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
513 |
"world", |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
514 |
} |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
515 |
using_a_callback(x, function(...) |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
516 |
print("hello") |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
517 |
end) |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
518 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
519 |
-- good |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
520 |
local my_table = { |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
521 |
"hello"; |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
522 |
"world"; |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
523 |
} |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
524 |
using_a_callback(x, function(...) |
9943
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
525 |
print("hello"); |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
526 |
end) |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
527 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
528 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
529 |
> **Rationale:** This keep indentation levels aligned at predictable places. You don't |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
530 |
need to realign the entire block if something in the first line changes (such as |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
531 |
replacing `x` with `xy` in the `using_a_callback` example above). |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
532 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
533 |
* The concatenation operator gets a pass for avoiding spaces: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
534 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
535 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
536 |
-- okay |
9943
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
537 |
local message = "Hello, "..user.."! This is your day # "..day.." in our platform!"; |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
538 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
539 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
540 |
> **Rationale:** Being at the baseline, the dots already provide some visual spacing. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
541 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
542 |
* No spaces after the name of a function in a declaration or in its arguments: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
543 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
544 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
545 |
-- bad |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
546 |
local function hello ( name, language ) |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
547 |
-- code |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
548 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
549 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
550 |
-- good |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
551 |
local function hello(name, language) |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
552 |
-- code |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
553 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
554 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
555 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
556 |
* Add blank lines between functions: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
557 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
558 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
559 |
-- bad |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
560 |
local function foo() |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
561 |
-- code |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
562 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
563 |
local function bar() |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
564 |
-- code |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
565 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
566 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
567 |
-- good |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
568 |
local function foo() |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
569 |
-- code |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
570 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
571 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
572 |
local function bar() |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
573 |
-- code |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
574 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
575 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
576 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
577 |
* Avoid aligning variable declarations: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
578 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
579 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
580 |
-- bad |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
581 |
local a = 1 |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
582 |
local long_identifier = 2 |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
583 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
584 |
-- good |
9943
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
585 |
local a = 1; |
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
586 |
local long_identifier = 2; |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
587 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
588 |
|
11004
d9aae4734f38
coding_style: Replace mention of git with hg
Kim Alvefur <zash@zash.se>
parents:
9943
diff
changeset
|
589 |
> **Rationale:** This produces extra diffs which add noise to `hg annotate`. |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
590 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
591 |
* Alignment is occasionally useful when logical correspondence is to be highlighted: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
592 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
593 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
594 |
-- okay |
9943
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
595 |
sys_command(form, UI_FORM_UPDATE_NODE, "a", FORM_NODE_HIDDEN, false); |
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
596 |
sys_command(form, UI_FORM_UPDATE_NODE, "sample", FORM_NODE_VISIBLE, false); |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
597 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
598 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
599 |
## Typing |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
600 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
601 |
* In non-performance critical code, it can be useful to add type-checking assertions |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
602 |
for function arguments: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
603 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
604 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
605 |
function manif.load_manifest(repo_url, lua_version) |
9943
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doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
606 |
assert(type(repo_url) == "string"); |
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
607 |
assert(type(lua_version) == "string" or not lua_version); |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
608 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
609 |
-- ... |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
610 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
611 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
612 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
613 |
* Use the standard functions for type conversion, avoid relying on coercion: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
614 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
615 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
616 |
-- bad |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
617 |
local total_score = review_score .. "" |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
618 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
619 |
-- good |
9943
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doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
620 |
local total_score = tostring(review_score); |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
621 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
622 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
623 |
## Errors |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
624 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
625 |
* Functions that can fail for reasons that are expected (e.g. I/O) should |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
626 |
return `nil` and a (string) error message on error, possibly followed by other |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
627 |
return values such as an error code. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
628 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
629 |
* On errors such as API misuse, an error should be thrown, either with `error()` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
630 |
or `assert()`. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
631 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
632 |
## Modules |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
633 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
634 |
Follow [these guidelines](http://hisham.hm/2014/01/02/how-to-write-lua-modules-in-a-post-module-world/) for writing modules. In short: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
635 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
636 |
* Always require a module into a local variable named after the last component of the module’s full name. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
637 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
638 |
```lua |
9943
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doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
639 |
local bar = require("foo.bar"); -- requiring the module |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
640 |
|
9943
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doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
641 |
bar.say("hello"); -- using the module |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
642 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
643 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
644 |
* Don’t rename modules arbitrarily: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
645 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
646 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
647 |
-- bad |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
648 |
local skt = require("socket") |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
649 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
650 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
651 |
> **Rationale:** Code is much harder to read if we have to keep going back to the top |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
652 |
to check how you chose to call a module. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
653 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
654 |
* Start a module by declaring its table using the same all-lowercase local |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
655 |
name that will be used to require it. You may use an LDoc comment to identify |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
656 |
the whole module path. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
657 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
658 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
659 |
--- @module foo.bar |
9943
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doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
660 |
local bar = {}; |
9862
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
661 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
662 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
663 |
* Try to use names that won't clash with your local variables. For instance, don't |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
664 |
name your module something like “size”. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
665 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
666 |
* Use `local function` to declare _local_ functions only: that is, functions |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
667 |
that won’t be accessible from outside the module. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
668 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
669 |
That is, `local function helper_foo()` means that `helper_foo` is really local. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
670 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
671 |
* Public functions are declared in the module table, with dot syntax: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
672 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
673 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
674 |
function bar.say(greeting) |
9943
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marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
675 |
print(greeting); |
9862
54147de1d1b1
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Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
676 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
677 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
678 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
679 |
> **Rationale:** Visibility rules are made explicit through syntax. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
680 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
681 |
* Do not set any globals in your module and always return a table in the end. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
682 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
683 |
* If you would like your module to be used as a function, you may set the |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
684 |
`__call` metamethod on the module table instead. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
685 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
686 |
> **Rationale:** Modules should return tables in order to be amenable to have their |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
687 |
contents inspected via the Lua interactive interpreter or other tools. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
688 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
689 |
* Requiring a module should cause no side-effect other than loading other |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
690 |
modules and returning the module table. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
691 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
692 |
* A module should not have state. If a module needs configuration, turn |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
693 |
it into a factory. For example, do not make something like this: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
694 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
695 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
696 |
-- bad |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
697 |
local mp = require "MessagePack" |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
698 |
mp.set_integer("unsigned") |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
699 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
700 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
701 |
and do something like this instead: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
702 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
703 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
704 |
-- good |
9943
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
705 |
local messagepack = require("messagepack"); |
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
706 |
local mpack = messagepack.new({integer = "unsigned"}); |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
707 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
708 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
709 |
* The invocation of require may omit parentheses around the module name: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
710 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
711 |
```lua |
9943
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
712 |
local bla = require "bla"; |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
713 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
714 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
715 |
## Metatables, classes and objects |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
716 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
717 |
If creating a new type of object that has a metatable and methods, the |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
718 |
metatable and methods table should be separate, and the metatable name |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
719 |
should end with `_mt`. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
720 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
721 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
722 |
local mytype_methods = {}; |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
723 |
local mytype_mt = { __index = mytype_methods }; |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
724 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
725 |
function mytype_methods:add_new_thing(thing) |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
726 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
727 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
728 |
local function new() |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
729 |
return setmetatable({}, mytype_mt); |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
730 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
731 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
732 |
return { new = new }; |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
733 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
734 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
735 |
* Use the method notation when invoking methods: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
736 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
737 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
738 |
-- bad |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
739 |
my_object.my_method(my_object) |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
740 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
741 |
-- good |
9943
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
742 |
my_object:my_method(); |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
743 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
744 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
745 |
> **Rationale:** This makes it explicit that the intent is to use the function as a method. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
746 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
747 |
* Do not rely on the `__gc` metamethod to release resources other than memory. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
748 |
If your object manage resources such as files, add a `close` method to their |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
749 |
APIs and do not auto-close via `__gc`. Auto-closing via `__gc` would entice |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
750 |
users of your module to not close resources as soon as possible. (Note that |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
751 |
the standard `io` library does not follow this recommendation, and users often |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
752 |
forget that not closing files immediately can lead to "too many open files" |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
753 |
errors when the program runs for a while.) |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
754 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
755 |
> **Rationale:** The garbage collector performs automatic *memory* management, |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
756 |
dealing with memory only. There is no guarantees as to when the garbage |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
757 |
collector will be invoked, and memory pressure does not correlate to pressure |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
758 |
on other resources. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
759 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
760 |
## File structure |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
761 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
762 |
* Lua files should be named in all lowercase. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
763 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
764 |
* Tests should be in a top-level `spec` directory. Prosody uses |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
765 |
[Busted](http://olivinelabs.com/busted/) for testing. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
766 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
767 |
## Static checking |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
768 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
769 |
All code should pass [luacheck](https://github.com/mpeterv/luacheck) using |
11731
f3aee8a825cc
Fix various spelling errors (thanks codespell)
Kim Alvefur <zash@zash.se>
parents:
11004
diff
changeset
|
770 |
the `.luacheckrc` provided in the Prosody repository, and using minimal |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
771 |
inline exceptions. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
772 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
773 |
* luacheck warnings of class 211, 212, 213 (unused variable, argument or loop |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
774 |
variable) may be ignored, if the unused variable was added explicitly: for |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
775 |
example, sometimes it is useful, for code understandability, to spell out what |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
776 |
the keys and values in a table are, even if you're only using one of them. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
777 |
Another example is a function that needs to follow a given signature for API |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
778 |
reasons (e.g. a callback that follows a given format) but doesn't use some of |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
779 |
its arguments; it's better to spell out in the argument what the API the |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
780 |
function implements is, instead of adding `_` variables. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
781 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
782 |
``` |
9943
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
783 |
local foo, bar = some_function(); --luacheck: ignore 212/foo |
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
784 |
print(bar); |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
785 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
786 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
787 |
* luacheck warning 542 (empty if branch) can also be ignored, when a sequence |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
788 |
of `if`/`elseif`/`else` blocks implements a "switch/case"-style list of cases, |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
789 |
and one of the cases is meant to mean "pass". For example: |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
790 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
791 |
```lua |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
792 |
if warning >= 600 and warning <= 699 then |
9943
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
793 |
print("no whitespace warnings"); |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
794 |
elseif warning == 542 then --luacheck: ignore 542 |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
795 |
-- pass |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
796 |
else |
9943
3a7f822f6edd
doc/coding_style: apply consistent semi-colon usage
marc0s <marcos@tenak.net>
parents:
9904
diff
changeset
|
797 |
print("got a warning: "..warning); |
9862
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
798 |
end |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
799 |
``` |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
800 |
|
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
801 |
> **Rationale:** This avoids writing negated conditions in the final fallback |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
802 |
case, and it's easy to add another case to the construct without having to |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
803 |
edit the fallback. |
54147de1d1b1
doc/coding_style.{txt,md}: Update coding style guide
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
804 |