def lets

bolt@1.27.0.0 · src/rules/table.bend:188

import Base
import bolt@1.27.0.0/src/syntax/lex.bend as Lex
import bolt@1.27.0.0/src/syntax/tree.bend as Tree

188# the keys of every name use under the node whose binding in scope is a
189# table: a let reaches the statements after it and their bodies, not an
190# enclosing block or a sibling arm, and a later let of the name replaces it
191def lets(nn: Tree.Node, +live: List<&2, String>, acc: List<&2, String>) -> List<&2, String>:
192  match nn:
193    case Tree.NCons{Tree.Stmt{kind, +kids, body}, rest}:
194      +next = rebind(bind_name(kids, False{}, False{}, ""), built(bind_rhs(kids)), live)
195      lets(rest, next, lets(body, live, lets(kids, live, acc)))
196    case Tree.NCons{Tree.Group{open, +kids, close}, rest}:
197      lets(rest, live, lets(kids, live, acc))
198    case Tree.NCons{Tree.Leaf{Lex.Tok{Lex.TName{}, +t, +l, +c}}, rest}:
199      lets(rest, live, use_at(t, l, c, live, acc))
200    case Tree.NCons{h, rest}:
201      lets(rest, live, acc)
202    case other:
203      acc