src/rules/laws/law.bend
bolt@1.11.0.0 · 166 lines · 0 definitions
1# rule coverage (project-wide; its module is law.bend, since `law` is a Bend
2# keyword and no bolt.bend could name it): in a project that states laws (a
3# LAWS.bend among the files the linter read), every def and type of every
4# file is reached from a quantified law in a LAWS.bend. A def is reached when
5# such a law names it (its binders or its statement use it, through an import
6# alias or in the law's own file), or when a reached def calls it: a use on
7# the def's lines, in its file or behind a relative import, across the files
8# of the run. A def no law reaches has no stated property, not even through
9# its callers: it is the coverage gap. A closed law, a law's own name, and a
10# law outside a LAWS.bend name nothing. A type is reached when such a law or
11# a reached def names it or one of its constructors (`M.Sq{..}` reaches a
12# `type Shape` with `Sq{..}`); a use of another def of its module does not
13# reach it, and a type reaches nothing. Out of scope: helper defs (dotted
14# names; a dotted type is graded, and a helper still carries the reach to
15# what it calls), tests, and the law files themselves -- decided by the name
16# and the file's path, never by what the file's text mentions. IO is no
17# exemption: a law can quantify over an IO value or state an IO equality, so
18# a def returning `IO(..)` is graded like any other, and so is every pure def
19# beside it. `main` is a def: a law that names it covers it. The rule reads
20# each file's digest (src/rules/digest.bend), never the parsed source: its
21# phases use the list three times, and a `+` reuse copies it. The reach is
22# one walk over one graph, the walk the unsafe rule takes over imports
23# (src/rules/imports.bend): its nodes are the defs, types and constructors
24# of the run by key (name, a space, path), and one more node, the empty key,
25# that leads to what the laws name.
26import Base
27import bolt@1.11.0.0/src/lazy/lazy.bend as Lazy
28import bolt@1.11.0.0/src/finding.bend as F
29import bolt@1.11.0.0/src/syntax/outline.bend as Outline
30import bolt@1.11.0.0/src/rules/digest.bend as Digest
31import bolt@1.11.0.0/src/rules/imports.bend as Imports
32
33# what the laws name
34# ------------------
35
36# a file's uses onto the others', when the file is a LAWS.bend
37def named.put(laws: Bool, ms: List<&2, Digest.Mention>, more: List<&2, Digest.Mention>) -> List<&2, Digest.Mention>:
38 match laws:
39 case True{}:
40 List.append(&2, Digest.Mention, ms, more)
41 case False{}:
42 more
43
44# what the laws of every LAWS.bend name (Digest.of records uses for no
45# other file; a digest list handed in from elsewhere is read the same way)
46def named(ds: List<&2, Digest.Digest>) -> List<&2, Digest.Mention>:
47 match ds:
48 case Nil{}:
49 Nil{}
50 case Con{Digest.Digest{path, norm, dir, is_laws, is_law_file, exempt, tops, says, deps, unsafes, laws}, rest}:
51 named.put(is_laws, says, named(rest))
52
53# the graph
54# ---------
55
56# an item's key: its name, a space, its file's path. A name has no space, so
57# no two items share one, and no item has the empty key
58def key(+pp: String, name: String) -> String:
59 name ++ " " ++ pp
60
61# the keys of what the mentions name
62def keys(ms: List<&2, Digest.Mention>) -> List<&2, String>:
63 match ms:
64 case Nil{}:
65 Nil{}
66 case Con{Digest.Mention{p, n}, rest}:
67 key(p, n) <> keys(rest)
68
69# a type's constructors, each a node that leads nowhere, onto the others
70def ctor_nodes(cs: List<&2, String>, +pp: String, more: List<&2, Imports.Edge>) -> List<&2, Imports.Edge>:
71 match cs:
72 case Nil{}:
73 more
74 case Con{c, rest}:
75 Imports.Edge{key(pp, c), []} <> ctor_nodes(rest, pp, more)
76
77# the items of a file as nodes onto the others: a def leads to what it
78# calls, a type and its constructors to nothing
79def nodes(ts: List<&2, Digest.Top>, +pp: String, more: List<&2, Imports.Edge>) -> List<&2, Imports.Edge>:
80 match ts:
81 case Nil{}:
82 more
83 case Con{Digest.Top{Outline.IDef{}, name, line, cs, calls}, rest}:
84 Imports.Edge{key(pp, name), keys(calls)} <> nodes(rest, pp, more)
85 case Con{Digest.Top{Outline.IType{}, name, line, cs, calls}, rest}:
86 Imports.Edge{key(pp, name), []} <> ctor_nodes(cs, pp, nodes(rest, pp, more))
87 case Con{other, rest}:
88 nodes(rest, pp, more)
89
90# the items of every file as nodes
91def graph.items(ds: List<&2, Digest.Digest>) -> List<&2, Imports.Edge>:
92 match ds:
93 case Nil{}:
94 Nil{}
95 case Con{Digest.Digest{path, norm, dir, is_laws, is_law_file, exempt, tops, says, deps, unsafes, laws}, rest}:
96 nodes(tops, norm, graph.items(rest))
97
98# the graph: the empty key first, leading to what the laws name, then the
99# items
100def graph(+ds: List<&2, Digest.Digest>) -> List<&2, Imports.Edge>:
101 Imports.Edge{"", keys(named(ds))} <> graph.items(ds)
102
103# a type's constructors: is one of them reached?
104def any_item(ns: List<&2, String>, +cl: List<&2, String>, +pp: String) -> Bool:
105 match ns:
106 case Nil{}:
107 False{}
108 case Con{name, rest}:
109 Lazy.or_else(Imports.has(cl, key(pp, name)), _u => any_item(rest, cl, pp))
110
111# what is in scope
112# ----------------
113
114# the directories that state laws
115def law_dirs(ds: List<&2, Digest.Digest>) -> List<&2, String>:
116 match ds:
117 case Nil{}:
118 Nil{}
119 case Con{Digest.Digest{path, norm, dir, is_laws, is_law_file, exempt, tops, says, deps, unsafes, laws}, rest}:
120 +more = law_dirs(rest)
121 Bool.pick(List<&2, String>, is_laws, dir <> more, more)
122
123# a def, or a type, that no law reaches
124def gaps(ts: List<&2, Digest.Top>, +cl: List<&2, String>, +pp: String, +path: String) -> List<&2, F.Finding>:
125 match ts:
126 case Nil{}:
127 Nil{}
128 case Con{Digest.Top{Outline.IDef{}, +name, +line, cs, calls}, rest}:
129 +more = gaps(rest, cl, pp, path)
130 Bool.pick(List<&2, F.Finding>,
131 Lazy.or_else(String.contains(name, "."), _u => Imports.has(cl, key(pp, name))), more,
132 F.Finding{path, line, 0, 0, "coverage", "No quantified law reaches def " ++ name ++ "."} <> more)
133 case Con{Digest.Top{Outline.IType{}, +name, +line, cs, calls}, rest}:
134 +more = gaps(rest, cl, pp, path)
135 Bool.pick(List<&2, F.Finding>, Lazy.or_else(Imports.has(cl, key(pp, name)), _u => any_item(cs, cl, pp)), more,
136 F.Finding{path, line, 0, 0, "coverage", "No quantified law reaches type " ++ name ++ " or any of its constructors."}
137 <> more)
138 case Con{other, rest}:
139 gaps(rest, cl, pp, path)
140
141# every file not exempt, against what the laws reach
142def check.go(ds: List<&2, Digest.Digest>, +cl: List<&2, String>) -> List<&2, F.Finding>:
143 match ds:
144 case Nil{}:
145 Nil{}
146 case Con{Digest.Digest{path, +norm, dir, is_laws, is_law_file, exempt, tops, says, deps, unsafes, laws}, rest}:
147 +more = check.go(rest, cl)
148 Lazy.stop(List<&2, F.Finding>, exempt, more,
149 _u => List.append(&2, F.Finding, gaps(tops, cl, norm, path), more))
150
151# what the laws reach: the walk from the empty key over the graph, built once
152def reached(+es: List<&2, Imports.Edge>) -> List<&2, String>:
153 Imports.closure.go(es, Imports.paths(es), List.length(&2, Imports.Edge, es), "")
154
155# a project states no laws: nothing of it is under law, and the graph is
156# never built (a project with no LAWS.bend pays nothing)
157def check.first(+ds: List<&2, Digest.Digest>, dirs: List<&2, String>) -> List<&2, F.Finding>:
158 match dirs:
159 case Nil{}:
160 Nil{}
161 case Con{d, rest}:
162 check.go(ds, reached(graph(ds)))
163
164# the rule, over every file the linter read
165def check(+ds: List<&2, Digest.Digest>) -> List<&2, F.Finding>:
166 check.first(ds, law_dirs(ds))