ts-lambda/src/core.ts at main · HomeArchbishop/ts-lambda · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
/* eslint-disable no-use-before-define */

// Lambda Abs
type TypeBindingIdx = number
type TypeFinalBody = (TypeAbs | TypeBindingIdx | TypeFinalBody)[]
type TypeMappedFinalBody = (TypeAbs | TypeMappedFinalBody)[]
export type TypeBody = TypeAbs | TypeFinalBody

export type TypeAbs = { _body: TypeBody, _bindings: TypeAbs[] }
export type TermAbs<Body extends TypeBody, Bindings extends TypeAbs[] = []> = {
  _body: Body,
  _bindings: Bindings
}

// Lambda App
export type UtilMapFrom<Body extends TypeFinalBody, SrcBindings extends TypeAbs[], Flatten extends boolean = false, SentenceHead extends boolean = true> =
  Body extends [infer FirstIdx extends TypeBindingIdx, ...infer Rest extends TypeFinalBody] ?
    (SrcBindings[FirstIdx] extends undefined ? true : false) & (`${FirstIdx}` extends `-${string}` ? true : false) extends true ?
      never
    : [SrcBindings[FirstIdx], ...UtilMapFrom<Rest, SrcBindings, Flatten, false>]
  : Body extends [infer FirstAbs extends TypeAbs, ...infer Rest extends TypeFinalBody] ?
    [FirstAbs, ...UtilMapFrom<Rest, SrcBindings, Flatten, false>]
  : Body extends [infer FirstBody extends TypeFinalBody, ...infer Rest extends TypeFinalBody] ?
    UtilMapFrom<FirstBody, SrcBindings> extends never ?
      never
    : Flatten | (SentenceHead & (FirstBody extends { length: 1 } ? true : false)) extends true ? // Flatten && (SentenceHead || len(FirstBody)=1)
      [...UtilMapFrom<FirstBody, SrcBindings, Flatten, SentenceHead>, ...UtilMapFrom<Rest, SrcBindings, Flatten, false>]
    : [UtilMapFrom<FirstBody, SrcBindings, Flatten, SentenceHead>, ...UtilMapFrom<Rest, SrcBindings, Flatten, false>]
  : []

export type TermApp<M extends TypeAbs, N extends TypeAbs> =
  M['_body'] extends TypeAbs ?
    TermAbs<M['_body']['_body'], [...M['_bindings'], N]>
  : M['_body'] extends TypeFinalBody ?
    TermAppRecursive<UtilMapFrom<M['_body'], [...M['_bindings'], N], true, true>>
  : never

export type TermAppRecursive<MNList extends TypeMappedFinalBody> =
  MNList extends [infer M extends TypeAbs] ?
    M
  : MNList extends [infer M extends TypeAbs, infer N extends TypeAbs] ?
    TermApp<M, N>
  : MNList extends [infer M extends TypeAbs, infer N extends TypeMappedFinalBody] ?
    TermApp<M, TermAppRecursive<N>>
  : MNList extends [infer M extends TypeAbs, infer N extends TypeAbs, ...infer RestNList extends TypeMappedFinalBody] ?
    TermAppRecursive<[TermApp<M, N>, ...RestNList]>
  : MNList extends [infer M extends TypeAbs, infer N extends TypeMappedFinalBody, ...infer RestNList extends TypeMappedFinalBody] ?
    TermAppRecursive<[TermApp<M, TermAppRecursive<N>>, ...RestNList]>
  : never