3 ms·

Great article, there aren't many resources for writing proc macros right now. However, I think this could be done with a generic impl of WritableTemplate for a

Great article, there aren't many resources for writing proc macros right now. However, I think this could be done with a generic impl of WritableTemplate for all T where T: Template.

majewsky 8y ago
Yeah, I dropped out after three paragraphs thinking that the author is waaay overdoing it. If this is just a toy example, it should be labeled as such.
atombender 8y ago
That bugged me, too -- if your entire article is about using a particular tool, then the reason for using that tool should be rock solid. I found the linked article [1] much more helpful in explaining procedural macros, even though it didn't offer many reasons to use them (other than linking to Serde etc.). [1] https://blog.rust-lang.org/2018/12/21/Procedural-Macros-in-Rust-2018.html https://blog.rust-lang.org/2018/12/21/Procedural-Macros-in-R...
redshirtrob 8y ago
Agreed. I was anxiously waiting for proc macros to land on stable for quite a while and was very happy when they did. But, when the time came to implement my custom derive I had to consult many sources. I ended up piecing together what I needed from a combination of: - Official documentation (The Book) - Blog posts - Reading Serde code (And Syn/Proc-Macro/Proc-Macro2) I also found the introduction of the proc-macro2 shim crate (however well intentioned) caused quite a bit of confusion. Specifically, it wasn't clean if I should use proc-macro or proc-macro2, and if I should be using the TokenStream exported by the former or the latter. Or should I be using one in some cases, and the other in some cases. Ditto for a few other things that I just can't recall right now. I did get things put together eventually, but I don't feel I understand things well enough to explain to someone else...yet. All that said, it's a hugely powerful feature and well worth the time if you need to do things that require intimate knowledge of the AST.

Great article, there aren't many resources for writing proc macros right now. However, I think this could be done with a generic impl of WritableTemplate for all T where T: Template.

majewsky 8y ago

Yeah, I dropped out after three paragraphs thinking that the author is waaay overdoing it. If this is just a toy example, it should be labeled as such.

atombender 8y ago

That bugged me, too -- if your entire article is about using a particular tool, then the reason for using that tool should be rock solid. I found the linked article [1] much more helpful in explaining procedural macros, even though it didn't offer many reasons to use them (other than linking to Serde etc.). [1] https://blog.rust-lang.org/2018/12/21/Procedural-Macros-in-Rust-2018.html https://blog.rust-lang.org/2018/12/21/Procedural-Macros-in-R...

redshirtrob 8y ago

Agreed. I was anxiously waiting for proc macros to land on stable for quite a while and was very happy when they did. But, when the time came to implement my custom derive I had to consult many sources. I ended up piecing together what I needed from a combination of: - Official documentation (The Book) - Blog posts - Reading Serde code (And Syn/Proc-Macro/Proc-Macro2) I also found the introduction of the proc-macro2 shim crate (however well intentioned) caused quite a bit of confusion. Specifically, it wasn't clean if I should use proc-macro or proc-macro2, and if I should be using the TokenStream exported by the former or the latter. Or should I be using one in some cases, and the other in some cases. Ditto for a few other things that I just can't recall right now. I did get things put together eventually, but I don't feel I understand things well enough to explain to someone else...yet. All that said, it's a hugely powerful feature and well worth the time if you need to do things that require intimate knowledge of the AST.