@wire_struct and wire_matrix help with naming WireVector slices

[fdxmw]

@wire_struct
class Byte:
    high: 4  # high is the four most significant bits.
    low: 4   # low is the four least significant bits.

This Byte @wire_struct can be instantiated two ways, by providing a value for each component:

  byte = Byte(high=0xA, low=0xB)

or by providing a value for the entire Byte:

  byte = Byte(Byte=0xAB)

After construction, byte is a WireVector representing the entire Byte (all 8 wires), byte.high is a WireVector representing the 4 most significant bits, and byte.low is a WireVector representing the 4 least significant bits.

wire_matrix is similar to @wire_struct, except that the slices are numbered instead of named, and all slices must share the same type:

# Four slices, each slice has bitwidth 8.
Word = wire_matrix(component_schema=8, size=4)
w = Word(values=[0x89ABCDEF])
print(w[0].bitwidth)  # Prints 8.

@wire_struct and wire_matrix can be composed arbitrarily, so you can have a two-dimensional array of Bytes for example.

@wire_struct and wire_matrix have additional features. See the documentation for details.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 97.57282% with 5 lines in your changes are missing coverage. Please review.

Project coverage is 91.26%. Comparing base (c8a7d75) to head (55044e2).

Files	Patch %	Lines
pyrtl/wire.py	94.25%	5 Missing :warning:

:exclamation: Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## development #439 +/- ## =============================================== + Coverage 90.92% 91.26% +0.33% =============================================== Files 24 24 Lines 6139 6341 +202 =============================================== + Hits 5582 5787 +205 + Misses 557 554 -3 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.