Enhance Witness struct element access methods:
- Rename `nth()` to `get()` for clearer slice-like element retrieval
- Introduce `get_back()` method for flexible reverse indexing
- Remove redundant `second_to_last()` and `third_to_last()` methods
- Add `#[track_caller]` to index implementation for better error tracking
- Update all references to use new method names
- Improve documentation with usage examples
The changes provide a more intuitive and consistent approach to
accessing witness elements.
This commit introduces `WrapDebug` in `internals` and updates `Witness`
debug implementation to use it. The previous `DebugElements` struct has
been removed in favor of an ad-hoc closure inside `WrapDebug`, which
formats witness elements as a debug list of hex-encoded values.
By abstracting out the "debug-print hex fields" pattern, we reduce
code duplication and improve maintainability.
8d8edd2c77 make Debug representation of Witness to be slice of hex-encoded bytes strings (Erick Cestari)
Pull request description:
This PR updates the Debug implementation for the Witness type to improve its readability by displaying the witness data as a slice of hex-encoded strings rather than a concatenated blob or list of raw u8 values. The changes include:
- Improved Output:
The debug output now shows pseudo-fields such as the number of elements and the total length of all elements, making it easier to understand the underlying data without exposing internal indices like indices_start.
- Hex-Encoding:
Each witness element is displayed as a hex-encoded string, similar to Bitcoin Core's output style, which enhances clarity during debugging sessions.
These changes should provide a more developer-friendly view of the witness data and align with similar patterns used elsewhere in the ecosystem.
Closes#4023.
Example display:
```
Witness {
num_elements: 3,
total_bytes: 5,
elements: [
0b,
1516,
1f20,
],
}
```
```
Witness { num_elements: 3, total_bytes: 5, elements: [0b, 1516, 1f20] }
```
ACKs for top commit:
tcharding:
ACK 8d8edd2c77
Kixunil:
ACK 8d8edd2c77
apoelstra:
ACK 8d8edd2c77de9b0423533fc70802171803761fcd; successfully ran local tests
Tree-SHA512: ffcdf67542049f405317eecd74876b51972d27ec552eec8e9c7b6324f18f31f4721fc4d2be1e596232c39af90a8d169c082f9b0636e5aa1a80fe1b063d645456
Cargo mutants found mutants in witness.
Add to the existing test `push` to kill the mutants from `is_empty` and
`third_to_last`.
Change the dummy values to make the progression of `elements` down the
test easier to follow.
Enable lint `clippy::return_self_not_must_use` and add attribute
`must_use` as required.
Also run the linter with `clippy::must_use_candidate` enabled and
manually check every warning site.
While we are at it change the current `must_use` usages to have no
message. We can always add a message later if needed.
In #2646 we introduced a bug in the taproot witness stack getter
functions, of which we have three:
- `tapscript`
- `taproot_control_block`
- `taproot_annex`
Each returns `Some` if a possible bytes slice is found (with no other
guarantees).
Use `taproot_annex` combined with getters from `primitives` to implement
the other two getters. This simplifies the code and fixes the bug.
Add an additional getter to `primitives` `Witness::third_from_last`.
Fix: #3598
There is a range of different wordings used in the docs of constructor
type functions.
Change all to start with `Constructs a new` or `Constructs an empty`.
In functions that act like constructors there is a mixture of the usage
of `creates` and `constructs`.
Replace all occurrences of `creates` with `constructs` in the first line
of docs of constructor like functions.
This has been fixed and we use nightly to lint so we have access to the
merged fix.
Removing the attribute uncovers a bunch of real lint warnings, fix
them while we are at it.
During this release cycle we deprecated `to_vec` in favour of
`to_bytes`, we have since reversed our position on the name.
Remove the deprecation of `to_bytes` from the three types that had it
and use `to_vec`.
Move the `Witness` over to `primitives` leaving behind any method that
takes or returns a `Script` or a signature.
Includes addition of a feature gate to unit test.
Erick Cestari
Jamil Lambert, PhD
merge-script
Fmt Bot
Tobin C. Harding