Re: Type inference and pragma issues in lambdas

[mratsim]

Oh, right, the issue is for proc within tuples: 
[https://github.com/nim-lang/Nim/issues/7808](https://github.com/nim-lang/Nim/issues/7808)

Re: Type inference and pragma issues in lambdas

[mashingan]

@adobai, this is work


proc doIt(x: string, p: proc()) =
  echo x

doIt("xx", proc() = echo "aa")


Run

Re: Type inference and pragma issues in lambdas

[idobai]

@juancarlospaco what's that supposed to be?

@mratsim the sugar module produces the same. Also, I REALLY don't want to type 
down {.closure.} every time I create a lambda function because it'd be insane. 
Also, I think it's wrong for a lambda to assume that it'll be a {.closure.} - 
it should allow everything by default unless explicitly defined otherwise.

Re: Type inference and pragma issues in lambdas

[mratsim]

For some reason procvar (proc parameter) sometimes need some help with either 
{.closure.} or {.nimcall.}


proc doIt(x: (string, proc(){.closure.})) =
  echo x[0]

doIt(("xx", proc() {.closure.} = echo "aa"))


Run

Be sure to check the `sugar` module as well for `->` and `=>` shortcuts


proc passTwoAndTwo(f: (int, int) -> int): int =
  f(2, 2)

passTwoAndTwo((x, y) => x + y) # 4


Run

Re: Type inference and pragma issues in lambdas

[juancarlospaco]

`(func: auto = "Lambda")() `

Run

Type inference and pragma issues in lambdas

[idobai]

Hi,

> Why is this an issue:


proc doIt(x: (string, proc(): void)) =
  echo x[0]

doIt(("xx", proc(): void = echo "aa"))


Run


Hint: used config file 
'/home/steven/.choosenim/toolchains/nim-0.19.0/config/nim.cfg' [Conf]
Hint: system [Processing]
Hint: t [Processing]
t.nim(5, 5) Error: type mismatch: got 
but expected one of:
proc doIt(x: (string, proc (): void))

expression: doIt(("xx", proc (): void = echo ["aa"]))


Run

Is there a sane way in nim to do lambdas?

Re: Type inference and pragma issues in lambdas

[idobai]

But this is ok:


proc doIt(x: (string, proc(): void)) =
  echo x[0]

proc make1(x: string, y: proc(): void): (string, proc(): void) = (x, y)

doIt(make1("xx", proc(): void = echo "aa"))


Run

Doesn't make any sense.