Tabs and Indents
Function or procedure call
Use tab character
Use TAB characters instead of SPACE characters for indents. A TAB character appears when you press ⇥. A SPACE character when you press Space.
Use combination of TAB and SPACE characters depending on the context.
Set the size of a single TAB character (in a number of SPACE characters).
Set the size of an indent (in a number of SPACE characters). Indent is a position of a text relative to the margin. In our case, the margin is a gutter with line numbers.
Add a number of SPACE characters to an indent on a next line for a multiline expression. Consider the following example with zero indent and aligned strings.
Keep indents on empty lines
Keep indents if the line is empty.