Sum (p.lrgrep.0.3.doc.fix.Fix.Indexing.Sum)

Module Indexing.SumSource

Sum(L)(R) creates a new type-level set, which is the disjoint sums of the sets L and R. The functor application Sum(L)(R) involves a call to cardinal L.n, thereby fixing the cardinal of the set L, if it was an open-ended set. The cardinal of the set R is not fixed: if R is an open-ended set, then the new set is open-ended as well, and it is still permitted to add new elements to R by calling R.fresh(). Fixing the cardinal of the new set fixes the cardinal of R.

Sourcetype (_, _) n

Sourceval cardinal : 'l cardinal -> 'r cardinal -> ('l, 'r) n cardinal

Sourceval inj_l : 'l index -> ('l, 'r) n index

Sourceval inj_r : 'l cardinal -> 'r index -> ('l, 'r) n index

Sourceval prj : 'l cardinal -> ('l, 'r) n index -> ('l index, 'r index) either

Sourcemodule type S = sig ... end

The signature SUM extends CARDINAL with an explicit isomorphism between the set n and the disjoint sum l + r. The functions inj_l and inj_r convert an index into l or an index into r into an index into n. Conversely, the function prj converts an index into r into either an index into l or an index into r.

Source

module Make
  (L : CARDINAL)
  (R : CARDINAL) : 
  S with type l := L.n and type r := R.n

Source

val make : 
  'l cardinal ->
  'r cardinal ->
  (module S
  with type l = 'l
   and type r = 'r)

The function sum is a value-level analogue of the functor Sum.