Accessing comments through AST

[otm]

I would like to annotate Lua code through comments, much like Go to generate documentation. However, I don't see the comments when I call parse.Dump.

How should I access the comments through the AST?

-- relase <var> [optionalVar]
function target.relase(var, optionalVar)

end

[yuin]

As comments are read and thrown away, you can not access comments through ASTs.
Instead, you can implement a library like lua-annotate.

[otm]

There is no way to change the implementation of the tokenizer so the comments are not thrown away and can be analyzed in the AST?

The reason is that it makes the desired syntax to complex.

[yuin]

ASTs in the GopherLua are currently just an intermediate-representing format for translating source codes to byte codes.
GopherLua's ASTs do not have interfaces like visitors, therefore, it is probably hard to analyze ASTs even if comments were not thrown away by the GopherLua parser.
I’m now busy with my work and I can't get much time to make these major alteration.

It might be good idea for you to fork the GopherLua and make it what you want.

[otm]

I will take a look at it. I might write a tiny purpose built tokenizer for this, as I'm only interested in functions and comments associated with them.

However, if you have any pointers on how to implement this is gopher-lua I'm interested. Also, would you be interested in a pull request regarding this?

[yuin]

However, if you have any pointers on how to implement this is gopher-lua I'm interested.

If I were you, I would not use ASTs.

1. LFunction objects have a FunctionProto object. This allows you to know where the function was defined.

lineDefined := fn.Proto.LineDefined

2. Read the .lua source file and check whether a line:lineDefined - 1 starts with -- .
3. If line:lineDefined -1 starts with --, parse this line as a directive.

Also, would you be interested in a pull request regarding this?

If you implement AST analyze functions and it is not causes significant performance degradation, I would like to consider merging.

[otm]

Thanks for the help! That is actally a really neat idea. I think that will work well.

Again, thanks for a really nice project.

[otm]

Your idea worked perfectly. I wrote a small tokenizer for Lua comments which emitted comments and line number and then used fn.Proto.LineDefined to check if there was a comment associated with the function.

[yuin]

Good to hear 👍

[flzyup]

I have a question, how do i get the the LFunction instance to read line number when i exe lua file or lua string. As we register global function as the following:

L.SetGlobal("double", L.NewFunction(Double)) /* Original lua_setglobal uses stack... */