Re: Lua style guide ?

[Sean Conner <sean@...>]

It was thus said that the Great Martin once stated:
> On 06/11/2017 04:15 PM, Sean Conner wrote:
> >   For example, this function:
> > 
> > 	function encode(value,sref,stref)
> > 	  local res = ""
> > 	
> > 	  if stref and not stref.SEEN then
> > 	    res = TAG._stringref(nil,nil,stref)
> > 	  end
> > 	
> > 	  return res .. __ENCODE_MAP[type(value)](value,sref,stref)
> > 	end
> > 
> > such a tool could return:
> > 
> > 	--- Placeholder
> > 	-- @function encode
> > 	-- @param value
> > 	-- @param sref
> > 	-- @param stref
> > 	-- @return
> > 	function encode(value,sref,stref)
> > 	...
> > 
> >   -spc (I don't understand the full scope of this, so of course it must be
> > 	trivial! 8-P
> 
> Hmm, as experiment I can create a breed of lua code formatter which
> produces output with such autogenerated comments. But is there really
> need for this?
> 
> Function in Lua may be defined in three ways:
> 
> 1. "local function <name> (<args>)" //<name> can't contain ":" syntel
> 2. "function <name> (<args>)"
> 3. "function (<args>)"

  Actually, you have:

	1. function <name>(<args>)
	2. local function <name>(<args>)
	3. function <name>.<name>(<args>) -- defined on a table
	4. function <name>:<name>(<args>) -- also defined on a table
	5. function (<args>) -- anonymous function

> Most obscure case is (3). It is often used as expression for sort() or
> gsub(). Do you have a good heuristic how do decide emit/not_emit header
> for function, given annotated syntax tree of source?

  As a first stab (and probably most useful) [1], just annotating style 1,
with maybe an option for style 2, would do [2].  Furthermore, if you could
determine if 2 was at the "global" level (that is, top level scope for a
file) and only do those would again be better.

> And by the way, are there good ways to test such formatter? Creating yet
> another rock with name like "lcf.experiments" looks like a bad idea.

  I'm not sure what you are asking here.

  -spc (Hmm ... not so trival after all 8-P

[1]	Just a gut feeling, no actual studies behind this.

[2]	I did mention I didn't understand the full scope of this.