Mapping = tuple[first, second: Tree]

MappingStore = ref object
  src*, dst*: Tree
  srcToDst, dstToSrc: Table[Tree, Tree]

MultiMappingStore = ref object
  srcToDsts*: Table[Tree, HashSet[Tree]]
  dstToSrcs*: Table[Tree, HashSet[Tree]]

proc `$`(this: MappingStore): string {....raises: [ValueError, Exception,
    NilArgumentError], tags: [RootEffect].}

proc addMapping(this: MappingStore; src: Tree; dst: Tree): void {.
    ...raises: [NilArgumentError], tags: [].}

proc addMapping(this: MultiMappingStore; src: Tree; dst: Tree): void {.
    ...raises: [NilArgumentError, KeyError, Exception], tags: [RootEffect].}

proc addMappingRecursively(this: MappingStore; src: Tree; dst: Tree): void {.
    ...raises: [NilArgumentError], tags: [].}

proc allMappedDsts(this: MultiMappingStore): HashSet[Tree] {.
    ...raises: [NilArgumentError], tags: [].}

proc allMappedSrcs(this: MultiMappingStore): HashSet[Tree] {.
    ...raises: [NilArgumentError], tags: [].}

proc areBothUnmapped(this: MappingStore; src: Tree; dst: Tree): bool {.
    ...raises: [NilArgumentError], tags: [].}

proc areDstsUnmapped(this: MappingStore; dsts: seq[Tree]): bool {.
    ...raises: [NilArgumentError], tags: [].}

proc areSrcsUnmapped(this: MappingStore; srcs: seq[Tree]): bool {.
    ...raises: [NilArgumentError], tags: [].}

proc getDstForSrc(this: MappingStore; src: Tree): Tree {.
    ...raises: [NilArgumentError, KeyError, Exception], tags: [RootEffect].}

proc getDsts(this: MultiMappingStore; src: Tree): HashSet[Tree] {.
    ...raises: [NilArgumentError, KeyError, Exception], tags: [RootEffect].}

proc getMappings(this: MultiMappingStore): HashSet[Mapping] {.
    ...raises: [NilArgumentError, KeyError, Exception], tags: [RootEffect].}

proc getSrcForDst(this: MappingStore; dst: Tree): Tree {.
    ...raises: [NilArgumentError, KeyError, Exception], tags: [RootEffect].}

proc getSrcs(this: MultiMappingStore; dst: Tree): HashSet[Tree] {.
    ...raises: [NilArgumentError, KeyError, Exception], tags: [RootEffect].}

proc has(this: MappingStore; src: Tree; dst: Tree): bool {.
    ...raises: [NilArgumentError, KeyError, Exception], tags: [RootEffect].}

proc has(this: MultiMappingStore; src: Tree; dst: Tree): bool {.
    ...raises: [NilArgumentError, KeyError, Exception], tags: [RootEffect].}

proc hasDst(this: MultiMappingStore; dst: Tree): bool {.
    ...raises: [NilArgumentError], tags: [].}

proc hasSrc(this: MultiMappingStore; src: Tree): bool {.
    ...raises: [NilArgumentError], tags: [].}

proc hasUnmappedDstChildren(this: MappingStore; t: Tree): bool {.
    ...raises: [NilArgumentError], tags: [].}

proc hasUnmappedSrcChildren(this: MappingStore; t: Tree): bool {.
    ...raises: [NilArgumentError], tags: [].}

proc isDstMapped(this: MappingStore; dst: Tree): bool {.
    ...raises: [NilArgumentError], tags: [].}

proc isDstUnique(this: MultiMappingStore; dst: Tree): bool {.
    ...raises: [NilArgumentError, KeyError, Exception], tags: [RootEffect].}

proc isMappingAllowed(this: MappingStore; src: Tree; dst: Tree): bool {.
    ...raises: [NilArgumentError], tags: [].}

proc isSrcMapped(this: MappingStore; src: Tree): bool {.
    ...raises: [NilArgumentError], tags: [].}

proc isSrcUnique(this: MultiMappingStore; src: Tree): bool {.
    ...raises: [NilArgumentError, KeyError, Exception], tags: [RootEffect].}

proc newMapping(a, b: Tree): Mapping {....raises: [], tags: [].}

proc newMappingStore(ms: MappingStore): MappingStore {.
    ...raises: [NilArgumentError], tags: [].}

proc newMappingStore(src: Tree; dst: Tree): MappingStore {.
    ...raises: [NilArgumentError], tags: [].}

proc newMultiMappingStore(): MultiMappingStore {....raises: [], tags: [].}

proc newMultiMappingStore(mappings: HashSet[Mapping]): MultiMappingStore {.
    ...raises: [NilArgumentError, KeyError, Exception], tags: [RootEffect].}

proc pprint(this: MappingStore) {....raises: [NilArgumentError, ImplementKindError,
    ImplementError, ValueError, Exception, ArgumentError, KeyError,
    NoneArgumentError], tags: [RootEffect, ReadEnvEffect].}

proc removeMapping(this: MultiMappingStore; src: Tree; dst: Tree): void {.
    ...raises: [NilArgumentError, KeyError, Exception], tags: [RootEffect].}

proc size(this: MappingStore): int {....raises: [], tags: [].}

proc size(this: MultiMappingStore): int {.
    ...raises: [NilArgumentError, KeyError, Exception], tags: [RootEffect].}

proc toString(this: MultiMappingStore): string {.
    ...raises: [NilArgumentError, KeyError, Exception, ValueError],
    tags: [RootEffect].}

iterator items(this: MappingStore): Mapping {....raises: [], tags: [].}

iterator items(this: MultiMappingStore): Mapping {.
    ...raises: [NilArgumentError, KeyError, Exception], tags: [RootEffect].}