Use Key instead of MiniscriptKey

[tcharding]

One of the main traits in this lib is MiniscriptKey, we can shorten this to Key with no loss of meaning. This makes the whole codebase more terse. Terse code, if clear, is easier to read because there is less clutter. Also terseness assists the formatter and can reduce lines of code.

This patch is the result of running

s/MiniscriptKey/Key/g on all source files.

Notes

This is an invasive change, I will not be offended if review is a simple 'no'. Outside the miniscript library users can still do miniscript::Key if the trait is too terse for their taste.

[sanket1729]

Over time, I have been liking shorter names. I see the pros and cons of this. I am okay with MsKey, will not oppose to Key if @apoelstra is okay with it.

Outside the miniscript library users can still do miniscript::Key

Deriving MiniscriptKey is only for super advanced users. We don't expect regular users to it.

[apoelstra]

I'm fine with Key, although because it needs to be imported (you have to use use miniscript::Key to get the trait methods, you can't use the fully-qualified name without a lot of noise) I worry that it may conflict with other key types.

On the other hand since edition 2018 you can do use miniscript::Key as _ right?

[tcharding]

Light bulb moment, what about we add this as well?

/// Export a type alias to make usage of the library more ergonomic since the
/// `Key` trait name is so generic that it may cause naming conflicts.
pub use Key as MiniscriptKey;

[apoelstra]

oo, I like it! ok, ACK renaming to Key, along with this shim (which also helps with backward compatibility)

[tcharding]

Changes in force push:

• Rebase on master
• Add the 'trait alias' as described above

[tcharding]

In the same vein we could shorten ScriptContext -> Context. This would give us, e.g.,

impl<P: Key, C: Context> fmt::Display for Miniscript<P, C> {

Above includes shorter generic identifiers also, I don't see why we use Pk and Ctx when P and C are perfectly clear?

[apoelstra]

ACK c3c5959

This is gonna cause a lot of merge conflicts..

[tcharding]

This is gonna cause a lot of merge conflicts..

Yes. This PR can be re-done at anytime. It requires only a single command (a shell alias I have) to search-and-replace MiniscriptKey with Key. Please feel free to leave this queued up for a time that is suitable in relation to other open PRs. No rush whatsoever.

[sanket1729]

Agreed, keeping this as the last PR to merge.

[tcharding]

Making this draft because I do not know how to time it, it can be done mechanically at any stage if/when we feel its needed.

[tcharding]

Too invasive.