Re: Error: got proc, but expected proc {.closure.}

[readysloth]

Thank you guys! You helped a lot!

Re: Error: got proc, but expected proc {.closure.}

[lscrd]

You need to provide an anonymous proc. This works:


import sugar

proc calc(a: int, b: int): (int) -> int =
  let diff = a - b
  result = proc (c: int): int =
result = c - diff


let diff_proc = calc(5, 6)
echo diff_proc(7)


Run

Re: Error: got proc, but expected proc {.closure.}

[Vindaar]

The proc you want to return shouldn't have a name. So this line:


result = proc differentiate(c: int): int =


Run

should be


result = proc (c: int): int =


Run

Re: Error: got proc, but expected proc {.closure.}

[doofenstein]

the error message could be better, but the problem is that a reguarly created 
proc (with name) is not a value.

There are two solutions: 


proc calc(a: int, b: int): (int) -> int =
  let diff = a - b
  result = proc(c: int): int =
result = c - diff


Run

or


proc calc(a: int, b: int): (int) -> int =
  let diff = a - b
  proc differentiate(c: int): int =
result = c - diff
  differentiate


Run