Disussion of proposal 2015-004 (Addition of Buffer module)

[kfl]

This issue is for discussion of proposal 2015-004 (Addition of Buffer module).

[JohnReppy]

One obvious possibility is to generalize this API to vectors (both monomorphic and polymorphic). For monomorphic vectors, we would then have a signature like

signature MONO_BUFFER =
  sig
    type elem
    type vector
    type slice
    type buf

    val new      : int -> buf
    val contents : buf -> vector
    val length   : buf -> int
    val clear    : buf -> unit
    val reset    : buf -> unit

    val addElem  : buf -> elem -> unit
    val addVec   : buf -> vector -> unit
    val addSlice : buf -> slice -> unit
  end

structure CharBuffer : MONO_BUFFER
    where type elem = CharVector.elem
    where type vector = CharVector.vector
    where type slice = CharVectorSlice.slice

I have changed the name of the size function to length, since that is the named used for vectors.

We could then define a StringBuffer module with addChar, addString, and addSubstring functions as a wrapper around the CharBuffer module.

[JohnReppy]

A couple of naming convention questions/comments. The addSubString function should be called addSubstring to match the conventions of the Basis. I also think that the type buf should be buffer, since we have mostly used complete words for type names.

[JohnReppy]

It might be useful to include a function for extracting a slice of the buffer

  val extract : buf * int * int option -> string

[JohnReppy]

I have posted a proposal for adding a MONO_BUFFER signature that generalizes this proposal.