I’m trying to parse Zig source with NimbleParsec and come across some cases like these:

• in the definition of containerdeclarations, it uses itself

containerdeclarations = choice(
  testdecl |> concat(containerdeclarations),
  toplevelcomptime |> concat(containerdeclarations),
  optional(doc_comment) |> optional(keyword_pub) |> concat(topleveldecl) |> concat(containerdeclarations)
)

• expr uses asmexpr indirectly while asmexpr uses expr

asmexpr =
  keyword_asm
  |> optional(keyword_volatile)
  |> concat(lparen)
  |> concat(expr)
  |> optional(asmoutput)
  |> concat(rparen)
primaryexpr =
  choice([
    asmexpr,
    ifexpr,
    keyword_break |> optional(breaklabel) |> optional(expr),
    keyword_comptime |> concat(expr),
    keyword_nosuspend |> concat(expr),
    keyword_continue |> optional(breaklabel),
    keyword_resume |> concat(expr),
    keyword_return |> optional(expr),
    optional(blocklabel) |> concat(loopexpr),
    block,
    curlysuffixexpr
  ])

prefixexpr = repeat(prefixop) |> concat(primaryexpr)

multiplyexpr = prefixexpr |> optional(multiplyop |> concat(prefixexpr))

additionexpr = multiplyexpr |> optional(additionop |> concat(multiplyexpr))

bitshiftexpr = additionexpr |> optional(bitshiftop |> concat(additionexpr))

bitwiseexpr = bitshiftexpr |> optional(bitwiseop |> concat(bitshiftexpr))

compareexpr = bitwiseexpr |> optional(compareop |> concat(bitwiseexpr))

boolandexpr = compareexpr |> optional(keyword_and |> concat(compareexpr))

boolorexpr = boolandexpr |> optional(keyword_or |> concat(boolandexpr))

expr = boolorexpr