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How to wrap up a function with a refinement so the refinement isn't required?

I am trying to wrap up functions with refinements in a generic way so they can be called without the refinement. For instance, ARRAY-INITIAL size value instead of ARRAY/INITIAL size value

wrap: function [refined [path!] args [block!]] [
    function args compose [
        (refined) (args)
    ]
]

array-initial wrap 'array/initial [size value]

Not too fancy. Seems to work in general, but this has something weird if you call it using a function:

>> n: 0 array/initial 4 does [++ n] 
== [10 11 12 13]

>> n: 10 array-initial 4 does [++ n]
== [10 10 10 10]

When I source it I get this:

>> source array-initial 
array-initial: make function! [[size value][array/initial size value]]

Okay, so what's happening is that the function is being called in the wrapper and the result of the call passed...not the function. One workaround would be to use a get-word to avoid the evaluation:

>> array-initial-2: function [size value] [array/initial size :value]

>> array-initial-2: 10 array-initial-2 4 does [++ n]
[10 11 12 13]

But I was looking for a general approach. What's the best way to proxy the parameters without having this happen?

like image 391
HostileFork says dont trust SE Avatar asked Nov 02 '22 02:11

HostileFork says dont trust SE


1 Answers

This was a fascinating exercise, gotta love SO.

Turns out you actually need a "do reduce" to wrap functions with get-word arguments ...

R3 only at the moment:

unrefine: func [
  "Return an equivalent function with the given refinements wired in."
  refined [any-path! block!] "The function, with the refinements to include."
  /local ospec spec body found p s w b r
] [
  ospec: spec-of get first refined: to lit-path! :refined
  body: append copy spec: make block! length? ospec copy/deep [do reduce []]
  append/only body/3 :refined
  parse ospec [
    set s 0 1 string! (all [s append spec s])
    any [
      set w [word! | get-word! | lit-word!] (
        append spec :w
        append body/3 either word! = type? :w [reduce ['quote to get-word! w]][w])
      set b 0 1 block! (
        all [b append/only spec copy b])
      set s 0 1 string! (
        all [s append spec copy s])
    |
      /local to end
    |
      set r refinement! (
        p: any [p tail spec]
        if not found: find next refined r [append spec r])
      set s 0 1 string! (all [not found s append spec copy s])
      any [
        set w [word! | get-word! | lit-word!] (
          either found [p: insert p :w][append spec :w]
          append body/3 either word! = type? :w [reduce ['quote to get-word! w]][w])
        set b 0 1 block! (
          all [b either found [p: insert/only p copy b][append/only spec copy b]])
        set s 0 1 string! (
          all [s either found [p: insert p copy s][append spec copy s]])
      ]
    ]
  ]
  func spec body
]
like image 146
MarkI Avatar answered Nov 04 '22 07:11

MarkI