1	import Base
2	
3	# Classifies the filesystem object reported by a metadata lookup.
4	type FileType is Data:
5	  Regular{}
6	  Directory{}
7	  Other{}
8	
9	# Stores the kind, size, and modification time returned by stat.
10	type Info is Data:
11	  Info{kind: FileType, size: U32, mtime: U32}
12	
13	def stat.raw(path: String) -> IO(Result<&1, &1, U32 & String, U32 & U32 & U32>):
14	  import "./effs/files_compat.c"
15	  import "./effs/files_compat.js"
16	
17	# Maps the operating-system kind code into the public file classification.
18	def kind_from_nat(kind: Nat) -> FileType:
19	  match kind:
20	    case 0n: Regular{}
21	    case 1n+rest:
22	      match rest:
23	        case 0n: Directory{}
24	        case 1n+rest: Other{}
25	
26	def stat.kind(kind: U32) -> FileType:
27	  kind_from_nat(U32.to_nat(kind))
28	
29	def stat.result(
30	  result: Result<&1, &1, U32 & String, U32 & U32 & U32>
31	) -> Result<&1, &1, U32 & String, Info>:
32	  match result:
33	    case Fail{error}: Fail{error}
34	    case Done{(kind, (size, mtime))}:
35	      Done{Info{stat.kind(kind), size, mtime}}
36	
37	# Reads filesystem metadata for a path.
38	def stat(path: String) -> IO(Result<&1, &1, U32 & String, Info>):
39	  do IO<Result<&1, &1, U32 & String, Info>>:
40	    result : Result<&1, &1, U32 & String, U32 & U32 & U32> <- stat.raw(path)
41	    return stat.result(result)
42	
43	# Removes a file or an empty directory at a path.
44	def remove(path: String) -> IO(Result<&1, &1, U32 & String, Unit>):
45	  import "./effs/files_compat.c"
46	  import "./effs/files_compat.js"
47	
48	# Renames a path using the filesystem's atomic rename operation.
49	def rename(from: String, to: String) -> IO(Result<&1, &1, U32 & String, Unit>):
50	  import "./effs/files_compat.c"
51	  import "./effs/files_compat.js"
52	
53	def read.words(file: File, max: U32) -> IO(File & Result<&1, &1, U32 & String, U32 & Array<U32>>):
54	  import "./effs/files_compat.c"
55	  import "./effs/files_compat.js"
56	
57	def write.words.once(
58	  file: File,
59	  offset: U32,
60	  len: U32,
61	  words: Array<U32>
62	) -> IO(File & Result<&1, &1, U32 & String, U32 & Array<U32>>):
63	  import "./effs/files_compat.c"
64	  import "./effs/files_compat.js"