should there be syntactic support for reading from a ternary expression?

[loreanvictor]

if is now an expression, which means we have ternary expressions like this:

prompt: What is your project URL?
default:
  if: git.remote_provider
  eval: 'https://{{ git.remote_provider }}/{{ git.remote_owner }}/{{ git.remote_name }}'
  else:
    eval: Enter some url ...

However, if takes precedence over all other commands and expressions in its node, which particularly means read cannot work with ternary expressions:

read: x
if: some condition
eval: some value
else:
  eval: some other value

👆 this code will read x if some condition holds, but won't read it otherwise (will just evaluate some other value to oblivion), since if takes precedence over read.

this can be simply fixed by introducing an expression similar to if but with lower priority (right below read):

read: x
where: some condition
eval: some value
else:
  eval: some other value

👆 this code will ALWAYS read x, even without an else clause it would read it into an empty string.

this is fairly straightforward since it is a copy of if rule, however it requires further contemplation of whether it is worth adding to syntax complexity for the convenience of read command (and only read command).

Pros

• Convenient reads with ternary expressions
• ??

Cons

• In a lot of cases, if and where will be interchangeable, i.e. two ways to do the same thing, which increases difficulty of reading recipe code.
• In cases that they are not, it might be confusing.
• Potential clash with this proposal. This is not a case of actual syntax ambiguity, since where would have lower priority to copy/update/remove (and other such commands). However it might result in increased difficulty of reading recipe code.
• ??

This should be further contemplated. For now, I will add the code and tests for the where rule, without adding it to the standard ruleset (should it be a parametrised if rule instead?)