Coding Standard (English)

Note: certain code, like code in applets and external libraries, do not need to follow this guideline.

Indentation

• Use 4 spaces.

End of file

• At the end of file, there should be an empty line (i.e. file ends with a line break character).

Naming conventions

Variable type	Naming style
Library	ALLCAPS
Library functions	smallCamelCase
Local functions	_underscoreAndSmallCamelCase
Global variables	ALLCAPS
Global functions	smallCamelCase
Local variables that need readable names	smallCamelCase
Simple local variables	initial letters of multiple words, or one single uppercase letter

Common code block formats

f() -- No semicolon needed at the end of lines

if c1 then
    s1
elseif c2 then
    s2
else
    s3
end

while c do
    s
end

for i=1,#l do
    s
end

for k,v in next,table do -- preferably replace `pairs(table)` with `next,table`
    s
end

repeat
    s
until c

do
    s
end

Comments

singleLineOfCode()-- comment 1

-- comment 2
Function definition or code block

--[[ Better begin with a short description so that can preview when folded
    Prefer leaving out the = sign whenever possible
    Comment content
]]
Function definition or code block

Strings

• "double quote": Text that might be read by players or developers
• 'single quote': Strings that only exist in code and never displayed
• [[double square brackets]] (leave out the = whenever possible): Large chunks of text

Code compacting

This section does not apply to：

• Imported Lua libraries and may retain the original author's code style
• "Syntax Comments" lines starting with ---@xxx
• Data code with large blocks aligned with spaces

Reduce spaces

• Do not add space around comma and (non-word) operator

- func(a, b, c)
+ func(a,b,c)

- x = 1 / (2 + 3)
+ x=1/(2+3)

Except:

• After "--"
• After "function" of nameless function

-- Comment
f=function() end

Merging line

• Merge multiple lines if it makes code looks more clear

a=5;  func(a)
b=10; func(b)

Reduce parenthesis

• If a function only takes one parameter
• and the parameter is a table or a string (TL: a table/string literal. Not when it's a table/string-type variable)
• then omit the parenthesis. For example,

GC.execute{100,40
    {'print',"Hello",0,0},
    {'print',"World",0,20},
}

Regex tool for reducing space

Use regex replace, replace \s([,+\-*/=><"']|==|>=|<=|~=|\.\.)|([,+\-*/=><"']|==|>=|<=|~=|\.\.)\s with $1$2

• NOTE: This WILL affect indentation. You can convert the indentation to tab, replace, then convert back.
• NOTE: This WILL trim off leading and trailing spaces in a string literal. You can remove ' and " in the expression
• NOTE: This WILL trim off leading and trailing spaces around --. You can remove - in the expression

Goto

All GOTO tags need to use one of the following prefixes

• BREAK_: similar to break in other languages, break out of loops (can break out any number of layers; may skip code in the rest of the loop)
• CONTINUE_: similar to continue in other languages, skip to end of loop to execute the next loop
• THROW_: similar to catch or except in other languages, for catching errors or jumping out of a code block for some actions
• REPEAT_: for returning to a point before to redo something