Calls.is_live.sign: def of bolt@1.27.0.0
Import: import bolt@1.27.0.0/src/rules/calls.bend as Calls
Lines 202-209 of bolt@1.27.0.0/src/rules/calls.bend: https://jend.leeeet.dev/read.txt?path=bolt@1.27.0.0/src/rules/calls.bend&start_line=202&end_line=209

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

# does the chain open with a `-` or `~` operator?
def is_live.sign(pp: Tree.Node) -> Bool:
  match pp:
    case Tree.NCons{+h, rest}:
      +t = leaf.text(h)
      Bool.and(kind.leaf(~kind.oper, h), Bool.or(String.eq(t, "-"), String.eq(t, "~")))
    case other:
      False{}

Uses (8):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.and
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.or
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String.eq
  https://jend.leeeet.dev/definition.txt?path=bolt@1.27.0.0/src/rules/calls.bend&name=kind.leaf
  https://jend.leeeet.dev/definition.txt?path=bolt@1.27.0.0/src/rules/calls.bend&name=kind.oper
  https://jend.leeeet.dev/definition.txt?path=bolt@1.27.0.0/src/rules/calls.bend&name=leaf.text
  https://jend.leeeet.dev/definition.txt?path=bolt@1.27.0.0/src/syntax/tree.bend&name=Node