src/lsp/path.bend

bolt@1.27.0.0 · 23 lines · 4 definitions

1# lsp/path: just enough path arithmetic to follow a relative import.
2import Base
3
4# a segment lands on the stack (reversed): `..` pops, `.` and `` do nothing
5def push(+seg: String, +acc: List<&2, String>) -> List<&2, String>:
6  Bool.pick(List<&2, String>, String.eq(seg, ".."), List.tail(&2, String, acc),
7    Bool.pick(List<&2, String>, Bool.or(String.eq(seg, "."), String.is_empty(seg)), acc, seg <> acc))
8
9# every segment pushed, in order
10def norm(segs: List<&2, String>, acc: List<&2, String>) -> List<&2, String>:
11  match segs:
12    case Nil{}:
13      acc
14    case Con{s, t}:
15      norm(t, push(s, acc))
16
17# dir and rel as one absolute path, its `.` and `..` resolved
18def join(dir: String, rel: String) -> String:
19  "/" ++ String.join(List.reverse(&2, String, norm(String.split(dir ++ "/" ++ rel, '/'), [])), "/")
20
21# the directory of a file's path
22def dir(path: String) -> String:
23  join(path, "..")