1	# rule hole: a TODO hole left in code, the one bend counts in "N TODO found":
2	# a `?` and then the name `TODO`, with any spaces, newlines or comments
3	# between them (`?TODO`, `? TODO`). `?todo`, `?TODO_later` and `?TODO.x` are
4	# other names, which bend reports as a type error, not as a TODO, and they are
5	# not reported here. The finding spans `?` through `TODO` when both sit on one
6	# line, and the `?` alone when `TODO` is on a later line. LAWS.bend is exempt:
7	# by convention its laws are open claims, filled by PROOF.bend beside it.
8	import Base
9	import ../../paths.bend as Paths
10	import ../../src.bend as Src
11	import ../../finding.bend as F
12	import ../../syntax/lex.bend as Lex
13	import ../../lazy/lazy.bend as Lazy
14	import ../calls.bend as Calls
15	
16	# True when the first token past spaces, newlines and comments is `TODO`
17	def check.todo(toks: List<&2, Lex.Tok>) -> Bool:
18	  match toks:
19	    case Con{Lex.Tok{+k, +t, l, c}, rest}:
20	      Lazy.stop(Bool, Lex.significant(k), Bool.and(Calls.kind.upper(k), String.eq(t, "TODO")), _u => check.todo(rest))
21	    case Nil{}:
22	      False{}
23	
24	# the width of the hole a `?` at line, col starts: through the next token
25	# past spaces, newlines and comments when it sits on the same line, else 1
26	def check.width(toks: List<&2, Lex.Tok>, +line: U32, +col: U32) -> U32:
27	  match toks:
28	    case Con{Lex.Tok{k, t, +l, +c}, rest}:
29	      Lazy.stop(U32, Lex.significant(k), Bool.pick(U32, U32.is_eq(l, line), U32.add(U32.sub(c, col), 4), 1),
30	        _u => check.width(rest, line, col))
31	    case Nil{}:
32	      1
33	
34	def check.go(toks: List<&2, Lex.Tok>, +path: String) -> List<&2, F.Finding>:
35	  match toks:
36	    case Con{Lex.Tok{k, +q, +l, +c}, +rest}:
37	      +more = check.go(rest, path)
38	      Lazy.stop(List<&2, F.Finding>, Bool.not(Bool.and(Calls.kind.oper(k), Lazy.and_then(String.eq(q, "?"),
39	        _u => check.todo(rest)))), more,
40	        _u => F.Finding{path, l, c, check.width(rest, l, c), "hole", "This ?TODO hole is still unfilled."} <> more)
41	    case Nil{}:
42	      Nil{}
43	
44	def check.on(toks: List<&2, Lex.Tok>, +path: String) -> List<&2, F.Finding>:
45	  Lazy.stop(List<&2, F.Finding>, Paths.is_laws(path), [], _u => check.go(toks, path))
46	
47	# the rule
48	def check(ss: Src.Src) -> List<&2, F.Finding>:
49	  Src.Src{path, text, toks, tree, bound, items} = ss
50	  check.on(toks, path)