Esteban Küber
1d78004575
Add Unicode block-drawing compiler output support
Add nightly-only theming support to rustc output using Unicode box
drawing characters instead of ASCII-art to draw the terminal UI:
After:
```
error: foo
╭▸ test.rs:3:3
│
3 │ X0 Y0 Z0
│ ┌───╿──│──┘
│ ┌│───│──┘
│ ┏││━━━┙
│ ┃││
4 │ ┃││ X1 Y1 Z1
5 │ ┃││ X2 Y2 Z2
│ ┃│└────╿──│──┘ `Z` label
│ ┃└─────│──┤
│ ┗━━━━━━┥ `Y` is a good letter too
│ `X` is a good letter
╰╴
note: bar
╭▸ test.rs:4:3
│
4 │ ┏ X1 Y1 Z1
5 │ ┃ X2 Y2 Z2
6 │ ┃ X3 Y3 Z3
│ ┗━━━━━━━━━━┛
├ note: bar
╰ note: baz
note: qux
╭▸ test.rs:4:3
│
4 │ X1 Y1 Z1
╰╴ ━━━━━━━━
```
Before:
```
error: foo
--> test.rs:3:3
|
3 | X0 Y0 Z0
| ___^__-__-
| |___|__|
| ||___|
| |||
4 | ||| X1 Y1 Z1
5 | ||| X2 Y2 Z2
| |||____^__-__- `Z` label
| ||_____|__|
| |______| `Y` is a good letter too
| `X` is a good letter
|
note: bar
--> test.rs:4:3
|
4 | / X1 Y1 Z1
5 | | X2 Y2 Z2
6 | | X3 Y3 Z3
| |__________^
= note: bar
= note: baz
note: qux
--> test.rs:4:3
|
4 | X1 Y1 Z1
| ^^^^^^^^
```
