Update tidy eval template

[lionel-]

Fixes r-lib/rlang#1008.

• Remove more advanced helpers.
• Mention modern syntax.
• Add examples.

[lionel-]

The {{ syntax conflicts with whiskers. Not sure how to solve this. Should we add an argument to use_template() to bypass render_template()?

[malcolmbarrett]

A trick that I've used to get around that is to treat {{ and }} like data, e.g. use {{{ curly_open }}} in the template, then data = list(curly_open = "{{") in use_template().

[jennybc]

I'll think about how to handle the clash between the content of this template and whisker. This template does not actually use whisker, so it's sort of sad that they are in tension.

Since the new template uses markdown syntax, I think use_tidy_eval() also needs to gain some logic to make sure the host package is using markdown with roxygen2.

[lionel-]

I'll think about how to handle the clash between the content of this template and whisker. This template does not actually use whisker, so it's sort of sad that they are in tension.

Thanks!

Since the new template uses markdown syntax, I think use_tidy_eval() also needs to gain some logic to make sure the host package is using markdown with roxygen2.

IIUC this is taken care of by the @md tag which enables markdown in single topic pages.

[jennybc]

IIUC this is taken care of by the @md tag which enables markdown in single topic pages.

But I think the host package still needs to have Roxygen: list(markdown = TRUE) in DESCRIPTION, yeah?

[jennybc]

Based on a small experiment, my concern about needing Roxygen: list(markdown = TRUE) doesn't seem to be warranted.