MetaPRL Indentation and Spacing Guidelines

Here is the list of basic indentation and spacing principles that we try to observe in MetaPRL:

• All indentation steps are 3 spaces.
• No tab symbols in the code.
• No spaces at the end of a line.
• It's OK to use spaces to make sure pieces of code are nicely aligned and/or indented, but in all other case at most one single space should be used, not several consecutive ones
• No empty lines at the beginning of a file, at the end of a file, or in the middle of a function.
• Functions are usually separated by an empty line.
• No more than one or two consecutive empty lines.
• Patterns are indented as follows:

  match
     expression
  with
     Choice1 ->
        code1
   | Choice2 ->
        code2
   | Choice3 ...

  When expression is short, its OK to use

  match expression with
     Choice1 ->
  ...

  When code_i is short, it's usually OK to put it on the same line with Code_i (but not with Code_i+1).
• let constructions should be aligned as follows:

  let variable =
     expression
  in
     code

  if expression is short, it's OK to use either

  let variable = expression in
  code

  or

  let variable = expression in code

  or even

  let variable = expression
  in code

  On the other hand, the following is discouraged:

  let very_long_variable_name = { field1 = code1;
                                  field2 = code21...
                                           code22...
                                      .....

  since it pushes the code too far to the right and makes it very hard to read in a narrow window. Instead, use

  let very_long_variable_name =
   { field1 = code1;
     field2 =
        code21...
        code22...
      ...

• The indentation examples above are only minimal requirements. If you feel like indenting some piece of code, you are welcome to do it, within reason. For example, many people like to indent the let example above as follows

  let variable = expression in
     code