Question about the language construct

[mk590901]

Is it possible in toit to describe several similar functions, place references to them in a list, and then call these functions one after another in a loop (through the list, naturally)?

[floitsch]

You can use lambdas:

main:
  lambdas := [
    :: print "hello",
    :: print "world",
  ]
  lambdas.do: | fun/Lambda |
     fun.call

[mk590901]

What if the function body includes multiple lines or actions, not just print?

…

On Tue, Jan 7, 2025, 11:21 Florian Loitsch ***@***.***> wrote: You can use lambdas: main: lambdas := [ :: print "hello", :: print "world", ] lambdas.do: | fun/Lambda | fun.call — Reply to this email directly, view it on GitHub <#2689 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A54VSXOGX3NPECGP2JHPBA32JOMC3AVCNFSM6AAAAABUXJCJVKVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTCNZVHA4TMOI> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[floitsch]

You can either use indentation, or call a function outside.
I also added (as example) parameters to the lambdas.

foo x y:
  print x
  print y

main:
  lambdas := [
    :: | x y | foo x y,  // Call other function.
    :: | x y |  // Inline with indentation.
      print x
      print y
  ]
  lambdas.do: | fun/Lambda |
    fun.call "hello" "world"

[mk590901]

I like this better: a1 -> none : print "A1" a2 -> none : print "A2" a3 -> none : print "A3" main : lambdas := [ :: a1, :: a2, :: a3 ] lambdas.do : | f/Lambda | f.call But in any case thanks a lot!

…

On Tue, Jan 7, 2025, 11:28 Florian Loitsch ***@***.***> wrote: You can either use indentation, or call a function outside. I also added (as example) parameters to the lambdas. foo x y: print x print y main: lambdas := [ :: | x y | foo x y, // Call other function. :: | x y | // Inline with indentation. print x print y ] lambdas.do: | fun/Lambda | fun.call "hello" "world" — Reply to this email directly, view it on GitHub <#2689 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A54VSXORBOGTA3VSOXVWE3T2JOM47AVCNFSM6AAAAABUXJCJVKVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTCNZVHEYDMMA> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[floitsch]

You can also assign the lambdas to local variables first:

main:
  fun1 := :: foo
  fun2 := :: bar
  ...
  lambdas := [ fun1, fun2, ... ]

[mk590901]

Ok

…

On Tue, Jan 7, 2025, 12:01 Florian Loitsch ***@***.***> wrote: You can also assign the lambdas to local variables first: main: fun1 := :: foo fun2 := :: bar ... lambdas := [ fun1, fun2, ... ] — Reply to this email directly, view it on GitHub <#2689 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A54VSXO3XLT2ASYWGSWFJS32JOQWPAVCNFSM6AAAAABUXJCJVKVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTCNZVHE2DKMA> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[mk590901]

Will this whole construction work if both functions and lambdas list are inside some class?

…

On Tue, Jan 7, 2025, 12:01 michael sure8 ***@***.***> wrote: Ok On Tue, Jan 7, 2025, 12:01 Florian Loitsch ***@***.***> wrote: > You can also assign the lambdas to local variables first: > > main: > fun1 := :: foo > fun2 := :: bar > ... > lambdas := [ fun1, fun2, ... ] > > — > Reply to this email directly, view it on GitHub > <#2689 (reply in thread)>, > or unsubscribe > <https://github.com/notifications/unsubscribe-auth/A54VSXO3XLT2ASYWGSWFJS32JOQWPAVCNFSM6AAAAABUXJCJVKVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTCNZVHE2DKMA> > . > You are receiving this because you authored the thread.Message ID: > ***@***.***> >

[floitsch]

Yes.

[mk590901]

I've found inside a class, the vector of lambda functions cannot be used due initialization error. ``` // define some class class Some : ab1 -> none : print "Ab1" ab2 -> none : print "Ab2" ab3 -> none : print "Ab3" list_/List := [ :: ab1, :: ab2, :: ab3 ] done : list_.do : | fun/Lambda | fun.call /* test_lambdas.toit:15:9: error: Can't access instance members in field initializers. :: ab1, :: ab2, :: ab3 ^~~ test_lambdas.toit:15:17: error: Can't access instance members in field initializers. :: ab1, :: ab2, :: ab3 ^~~ test_lambdas.toit:15:25: error: Can't access instance members in field initializers. :: ab1, :: ab2, :: ab3 ^~~ Compilation failed. */ a1 -> none : print "A1" a2 -> none : print "A2" a3 -> none : print "A3" main : lambdas := [ :: a1, :: a2, :: a3 ] lambdas.do : | fun/Lambda | fun.call // Works! ```

…

On Tue, Jan 7, 2025, 18:28 Florian Loitsch ***@***.***> wrote: Yes. — Reply to this email directly, view it on GitHub <#2689 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A54VSXONGWW7A7N2QZXLCYD2JP6EPAVCNFSM6AAAAABUXJCJVKVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTCNZWGMYTAOA> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[mk590901]

All works if you rewrite the class as follows: class Some : list_/List := [] ab1 -> none : print "Ab1" ab2 -> none : print "Ab2" ab3 -> none : print "Ab3" size : print "size->$list_.size" create : list_.add ::ab1 list_.add ::ab2 list_.add ::ab3 done : list_.do : | fun/Lambda | fun.call main : some := Some some.create some.size some.done // Works! Sorry for the trouble.

…

On Wed, Jan 8, 2025, 08:10 michael sure8 ***@***.***> wrote: I've found inside a class, the vector of lambda functions cannot be used due initialization error. // define some class class Some : ab1 -> none : print "Ab1" ab2 -> none : print "Ab2" ab3 -> none : print "Ab3" list_/List := [ :: ab1, :: ab2, :: ab3 ] done : list_.do : | fun/Lambda | fun.call /* test_lambdas.toit:15:9: error: Can't access instance members in field initializers. :: ab1, :: ab2, :: ab3 ^~~ test_lambdas.toit:15:17: error: Can't access instance members in field initializers. :: ab1, :: ab2, :: ab3 ^~~ test_lambdas.toit:15:25: error: Can't access instance members in field initializers. :: ab1, :: ab2, :: ab3 ^~~ Compilation failed. */ a1 -> none : print "A1" a2 -> none : print "A2" a3 -> none : print "A3" main : lambdas := [ :: a1, :: a2, :: a3 ] lambdas.do : | fun/Lambda | fun.call // Works! On Tue, Jan 7, 2025, 18:28 Florian Loitsch ***@***.***> wrote: > Yes. > > — > Reply to this email directly, view it on GitHub > <#2689 (reply in thread)>, > or unsubscribe > <https://github.com/notifications/unsubscribe-auth/A54VSXONGWW7A7N2QZXLCYD2JP6EPAVCNFSM6AAAAABUXJCJVKVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTCNZWGMYTAOA> > . > You are receiving this because you authored the thread.Message ID: > ***@***.***> >

[floitsch]

You can also set the list in the constructor of the class:

class Some:
  constructor:
    create  // Or inline the 'create' function here.
  ...