def scan

bend-lint-rules@0.2.0.0 · language/reused_binder.bend:111

import Base
import bend-lint-api@0.2.0.0/linter/lint.bend as Lint

111# The live uses of `b` among `nodes`, the nodes under one, after `seen`: `live` says whether they are live, `apart`
112# whether each is a path of its own (a match's), and `typed` whether only the first is live (an annotation's: the
113# second is a type); `at` counts the nodes.
114def scan(
115  nodes: List<&2, Lint.Node>,
116  +b: U32,
117  +live: Bool,
118  +apart: Bool,
119  +typed: Bool,
120  +at: U32,
121  seen: Seen
122) -> Seen:
123  match nodes:
124    case Nil{}:
125      seen
126    case Con{Lint.Node{+syntax, name, span, +kids, facts}, rest}:
127      +node = {Lint.Node{syntax, name, span, kids, facts}: Lint.Node}
128      +here = live && Bool.not(typed && U32.is_gt(at, 0))
129      scan(
130        rest,
131        b,
132        live,
133        apart,
134        typed,
135        (at + 1: U32),
136        Seen.then(
137          apart,
138          seen,
139          Seen.of(
140            node,
141            b,
142            here,
143            scan(
144              kids,
145              b,
146              is_live_inside(node, here),
147              is_match(syntax),
148              is_annotation(syntax),
149              0,
150              Seen{None{}, None{}}
151            )
152          )
153        )
154      )