resultUtils.swift

import * from PackTypes.Result
let module P = PackTypes.Parsing
let rec getChild = (children, mapper) => switch children {
  case []: None
  case [child ...rest]: switch mapper(child) {
    case None: getChild(rest, mapper)
    case x: x
  }
}
let rec getChildren = (children, mapper) => switch children {
  case []: []
  case [child ...rest]: switch mapper(child) {
    case None: getChildren(rest, mapper)
    case Some(x): [x, getChildren(rest, mapper)]
  }
}
let getContentsByLabel = (children, needle) => getChild(
  children,
  (label, child) => if (needle <> label) { None } else { switch child {
    case Leaf(_, contents, _): Some(contents)
    case Node(_): failwith("expected a leaf")
  } }
)
let getContentsByType = (children, needle) => getChild(
  children,
  child => switch child {
    case (_, Leaf((name, _), contents, _)) with (name = needle): Some(contents)
    case (_, Node((name, _), _, _)) with (name = needle): failwith("expected a leaf")
    case _: None
  }
)
let rec getPresence = (children, mapper) => switch children {
  case []: false
  case [child ...rest]: switch mapper(child) {
    case false: getPresence(rest, mapper)
    case x: x
  }
}
let getPresenceByLabel = (children, needle) => getPresence(
  children,
  child => switch child {
    case (name, _) with (name = needle): true
    case _: false
  }
)
let getPresenceByType = (children, needle) => getPresence(
  children,
  child => switch child {
    case (_, Leaf((name, _), _, _)) | (_, Node((name, _), _, _)) with (name = needle): true
    case _: false
  }
)
let getNodeByType = (children, needle) => getChild(
  children,
  (label, child) => if (label <> "") { None } else { switch child {
    case Node((name, sub), children, loc) with (name = needle): Some(sub, children, loc)
    case _: None
  } }
)
let getNodesByType = (children, needle, nodeMapper) => getChildren(
  children,
  (label, child) => switch child {
    case Node((name, sub), children, loc) with (name = needle): Some(nodeMapper((sub, children, loc)))
    case _: None
  }
)
let getNodesByLabel = (children, needle, nodeMapper) => getChildren(
  children,
  (label, child) => if (label = needle) { switch child {
    case Node((name, sub), children, loc): Some(nodeMapper((sub, children, loc)))
    case _: None
  } } else { None }
)
let getNodeByLabel = (children, needle) => getChild(
  children,
  (label, child) => if (label = needle) { switch child {
    case Node(rule, children, loc): Some(rule, children, loc)
    case Leaf(_): failwith(("Expected node for label " ^ needle))
  } } else { None }
)
let getLeafByType = (children, needle) => getChild(
  children,
  (label, child) => switch child {
    case Leaf((name, sub), contents, loc) with (name = needle): Some((name, sub), contents, loc)
    case _: None
  }
)
let unescapeString = x => {
  let contents = String.sub(x, 1, (String.length(x) - 2))
  if (String.length(contents) = 1) { contents } else { Scanf.unescaped(contents) }
}
let unescapeChar = x => if (String.length(x) = 1) { String.get(x, 0) } else { String.get(unescapeString(x), 0) }
exception ConversionFailure ( string )
let unwrap = opt => switch opt {
  case Some(x): x
  case None: raise(ConversionFailure("Unwrapping none"))
}
let assertEq = (one, two) => if (one <> two) { raise(ConversionFailure("Assertion error")) }