Modular•16mo ago

Error:cannot construct 'Array' from 'ListLiteral[Int, Int, Int, Int, Int]' value in 'var' initialize

I'm trying to create a Array[T: AnyType, N: Int] struct but encountered this error when trying to run it:

from memory import stack_allocation

struct Array[T: AnyType, N: Int]:
   constrained[N <= 32, "`size` of N cannot be larger than 1024"]()
   alias size: Int = N
   alias type: AnyType = T 

   var capacity: Int
   var length: Int
   var storage: Pointer[T]

   fn __init__[*Ts: AnyType](inout self, owned iterable: ListLiteral[Ts]) raises:
      if N != len(iterable):
         raise Error("`size` of `iterable` is not equal to the `size` of array")
      self.capacity = self.size * 2
      self.storage = stack_allocation[N*2, T]()
      let src: Pointer[T] = Pointer.address_of(iterable).bitcast[T]()
      for i in range(len(iterable)):
         self.storage.store(i, src.load(i))
      

fn main():
   var myarray: Array[Int, 5] = Array([1, 2, 3, 4, 5])

from memory import stack_allocation

struct Array[T: AnyType, N: Int]:
   constrained[N <= 32, "`size` of N cannot be larger than 1024"]()
   alias size: Int = N
   alias type: AnyType = T 

   var capacity: Int
   var length: Int
   var storage: Pointer[T]

   fn __init__[*Ts: AnyType](inout self, owned iterable: ListLiteral[Ts]) raises:
      if N != len(iterable):
         raise Error("`size` of `iterable` is not equal to the `size` of array")
      self.capacity = self.size * 2
      self.storage = stack_allocation[N*2, T]()
      let src: Pointer[T] = Pointer.address_of(iterable).bitcast[T]()
      for i in range(len(iterable)):
         self.storage.store(i, src.load(i))
      

fn main():
   var myarray: Array[Int, 5] = Array([1, 2, 3, 4, 5])

Please help.

27 Replies

Stole•16mo ago

I think you want to change that last Array([1, 2, 3, 4, 5]) to Array[Int, 5]([1, 2, 3, 4, 5]), and change fn main(): to fn main() raises:, since your __init__ can raise. Or you can wrap that initialization inside of main in a try block

JIMCOP•16mo ago

from memory import stack_allocation

struct Array[T: AnyType, N: Int]:
   alias size: Int = N
   alias type: AnyType = T 

   var capacity: Int
   var storage: Pointer[T]

   @always_inline("nodebug")
   fn __init__(inout self, size: Int, value: T) raises:
      if N != size:
         raise Error("`size` of `iterable` is not equal to the `size` of this array")
      self.capacity = self.size * 2
      self.storage = stack_allocation[N*2, T]()
      for i in range(self.size):
         self.storage.store(i, value)

   @always_inline("nodebug")
   fn __getitem__(self, i: Int) -> T:
        return self.storage.load(i)

   @always_inline("nodebug")
   fn __del__(owned self):
      self.storage.free()

fn main() raises:
   var myarray = Array[Int, 5](5, 2)
   print(myarray[2])

from memory import stack_allocation

struct Array[T: AnyType, N: Int]:
   alias size: Int = N
   alias type: AnyType = T 

   var capacity: Int
   var storage: Pointer[T]

   @always_inline("nodebug")
   fn __init__(inout self, size: Int, value: T) raises:
      if N != size:
         raise Error("`size` of `iterable` is not equal to the `size` of this array")
      self.capacity = self.size * 2
      self.storage = stack_allocation[N*2, T]()
      for i in range(self.size):
         self.storage.store(i, value)

   @always_inline("nodebug")
   fn __getitem__(self, i: Int) -> T:
        return self.storage.load(i)

   @always_inline("nodebug")
   fn __del__(owned self):
      self.storage.free()

fn main() raises:
   var myarray = Array[Int, 5](5, 2)
   print(myarray[2])

now i tried this

root@DESKTOP-N84UN90:~/mojo_projs/marray# [6725:6726:20230911,012436.045090:ERROR http_transport_libcurl.cc:483] HTTP status 404
mojo array.mojo
munmap_chunk(): invalid pointer
[6849:6849:20230911,012533.599369:ERROR file_io_posix.cc:144] open /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq: No such file or directory (2)
[6849:6849:20230911,012533.599465:ERROR file_io_posix.cc:144] open /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq: No such file or directory (2)
Please submit a bug report to https://github.com/modularml/mojo/issues and include the crash backtrace along with all the relevant source codes.
Stack dump:
0.      Program arguments: mojo array.mojo
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  mojo      0x00005622408e3957
1  mojo      0x00005622408e152e
2  mojo      0x00005622408e402f
3  libc.so.6 0x00007f84e78b7520
4  libc.so.6 0x00007f84e790ba7c pthread_kill + 300
5  libc.so.6 0x00007f84e78b7476 raise + 22
6  libc.so.6 0x00007f84e789d7f3 abort + 211
7  libc.so.6 0x00007f84e78fe6f6
8  libc.so.6 0x00007f84e7915d7c
9  libc.so.6 0x00007f84e791605c
10 libc.so.6 0x00007f84e791a51a free + 186
11 libc.so.6 0x00007f847400106a free + 18446744071770631178
Aborted

root@DESKTOP-N84UN90:~/mojo_projs/marray# [6725:6726:20230911,012436.045090:ERROR http_transport_libcurl.cc:483] HTTP status 404
mojo array.mojo
munmap_chunk(): invalid pointer
[6849:6849:20230911,012533.599369:ERROR file_io_posix.cc:144] open /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq: No such file or directory (2)
[6849:6849:20230911,012533.599465:ERROR file_io_posix.cc:144] open /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq: No such file or directory (2)
Please submit a bug report to https://github.com/modularml/mojo/issues and include the crash backtrace along with all the relevant source codes.
Stack dump:
0.      Program arguments: mojo array.mojo
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  mojo      0x00005622408e3957
1  mojo      0x00005622408e152e
2  mojo      0x00005622408e402f
3  libc.so.6 0x00007f84e78b7520
4  libc.so.6 0x00007f84e790ba7c pthread_kill + 300
5  libc.so.6 0x00007f84e78b7476 raise + 22
6  libc.so.6 0x00007f84e789d7f3 abort + 211
7  libc.so.6 0x00007f84e78fe6f6
8  libc.so.6 0x00007f84e7915d7c
9  libc.so.6 0x00007f84e791605c
10 libc.so.6 0x00007f84e791a51a free + 186
11 libc.so.6 0x00007f847400106a free + 18446744071770631178
Aborted

i get a mad error

Stole•16mo ago

~~Oops. I forgot that the ListLiteral passed is destroyed immediately.~~

TeamPuzel•16mo ago

You can also omit the constructor and write

var array: Array[Int, 5] = [1, 2, 3, 4, 5]

var array: Array[Int, 5] = [1, 2, 3, 4, 5]

It's a bit easier to both type and read

Stole•16mo ago

Wait, this is quite different.

JIMCOP•16mo ago

this works but...

from memory import stack_allocation

struct Array[T: AnyType, N: Int]:
   alias size: Int = N
   alias type: AnyType = T 

   var capacity: Int
   var storage: Pointer[T]

   fn __init__[*Ts: AnyType](inout self, owned iterable: ListLiteral[Ts]) raises:
      if N != len(iterable):
         raise Error("`size` of `iterable` is not equal to the `size` of array")
      self.capacity = self.size * 2
      self.storage = stack_allocation[N*2, T]()
      let src: Pointer[T] = Pointer.address_of(iterable).bitcast[T]()
      for i in range(len(iterable)):
         self.storage.store(i, src.load(i))

   fn __getitem__(self, idx: Int) -> T:
      return self.storage[idx]
      

fn main() raises:
   var myarray: Array[Int, 5] = [1, 2, 3, 4]
   print(myarray[2])

from memory import stack_allocation

struct Array[T: AnyType, N: Int]:
   alias size: Int = N
   alias type: AnyType = T 

   var capacity: Int
   var storage: Pointer[T]

   fn __init__[*Ts: AnyType](inout self, owned iterable: ListLiteral[Ts]) raises:
      if N != len(iterable):
         raise Error("`size` of `iterable` is not equal to the `size` of array")
      self.capacity = self.size * 2
      self.storage = stack_allocation[N*2, T]()
      let src: Pointer[T] = Pointer.address_of(iterable).bitcast[T]()
      for i in range(len(iterable)):
         self.storage.store(i, src.load(i))

   fn __getitem__(self, idx: Int) -> T:
      return self.storage[idx]
      

fn main() raises:
   var myarray: Array[Int, 5] = [1, 2, 3, 4]
   print(myarray[2])

this doesn't raise a compile time error lol

Stole•16mo ago

You'd probably want to change [1, 2, 3, 4] to [1, 2, 3, 4, 5] So it actually has 5 elements

JIMCOP•16mo ago

LOL sir you are very confused it is done on purpose with 4 elements, I want it to give me a compile time error

TeamPuzel•16mo ago

huh

JIMCOP•16mo ago

https://docs.modular.com/mojo/stdlib/builtin/constrained.html

Modular Docs - constrained

Module

JIMCOP•16mo ago

Using constrained

from memory import stack_allocation

struct Array[T: AnyType, N: Int]:
   alias size: Int = N
   alias type: AnyType = T 

   var capacity: Int
   var storage: Pointer[T]

   fn __init__[*Ts: AnyType](inout self, owned iterable: ListLiteral[Ts]) raises:
      constrained(N != len(iterable), "`size` of `iterable` is not equal to the `size` of array")
      self.capacity = self.size * 2
      self.storage = stack_allocation[N*2, T]()
      let src: Pointer[T] = Pointer.address_of(iterable).bitcast[T]()
      for i in range(len(iterable)):
         self.storage.store(i, src.load(i))

   fn __getitem__(self, idx: Int) -> T:
      return self.storage[idx]
      

fn main() raises:
   var myarray: Array[Int, 5] = [1, 2, 3, 4]
   print(myarray[2])

from memory import stack_allocation

struct Array[T: AnyType, N: Int]:
   alias size: Int = N
   alias type: AnyType = T 

   var capacity: Int
   var storage: Pointer[T]

   fn __init__[*Ts: AnyType](inout self, owned iterable: ListLiteral[Ts]) raises:
      constrained(N != len(iterable), "`size` of `iterable` is not equal to the `size` of array")
      self.capacity = self.size * 2
      self.storage = stack_allocation[N*2, T]()
      let src: Pointer[T] = Pointer.address_of(iterable).bitcast[T]()
      for i in range(len(iterable)):
         self.storage.store(i, src.load(i))

   fn __getitem__(self, idx: Int) -> T:
      return self.storage[idx]
      

fn main() raises:
   var myarray: Array[Int, 5] = [1, 2, 3, 4]
   print(myarray[2])

Moosems / Three chickens•16mo ago

You have to fill up the array with default values then.

JIMCOP•16mo ago

Hi sir, can you elaborate?

Moosems / Three chickens•16mo ago

See the array implementation that some of the devs and I made: https://discord.com/channels/1087530497313357884/1146821935112667288/1148339799808299038 Custom types are necessary until traits get implemented.

Stole•16mo ago

Sorry about that. I don't think you can in this case, fetching the length of that ListLiteral isn't done at compile time in this case

JIMCOP•16mo ago

Guess you made sense 🙂

ModularBot•16mo ago

Congrats @JIMC, you just advanced to level 1!

JIMCOP•16mo ago

That's your impl? Cool

Moosems / Three chickens•16mo ago

That’s what me and the devs arrived at, yes. I believe it should accomplish the behavior you’re looking for.

JIMCOP•16mo ago

I don't think it does, because I want a compile time check e.g. var my_array: Array[Int, 5] = [1, 2, 3] will have a compile time error that's what i want

Stole•16mo ago

And I don't think you can pass it as a parameter either, because trying to do something like fn __init__[*Ts: AnyType, iterable: ListLiteral[Ts]](inout self) raises: has a parameter pack plus normal parameters, and the error states keyword args aren't supported yet

Moosems / Three chickens•16mo ago

You could modify it to receive compile time values.

JIMCOP•16mo ago

How do you do try, except in Mojo?

TeamPuzel•16mo ago

try except finally it works the same way as in python but you raise Error not exception

JIMCOP•16mo ago

yeah but you cannot capture the error message right? @Three chickens in the green bag Anyway, array is not growable so i think your impl is a vector and usually a compile time construct

Moosems / Three chickens•16mo ago

Yes, it is a DynamicVector.

JIMCOP•16mo ago

from memory import stack_allocation

struct IntType[num: Int]:
   alias value: Int = num

fn comptime_add[NumOne: Int, NumTwo: Int]() -> Int:
   return NumOne + NumTwo

struct Array[T: AnyType, N: Int]:
   alias size: Int = N

   var capacity: Int
   var storage: Pointer[T]

   @staticmethod
   fn check_size[Size: Int]() raises -> Int:
      print("Size is ", Size)
      @parameter
      if Size <= N:
         return Size
      else:
         raise Error("`{Size}`")

   fn __init__[*Ts: AnyType](inout self, owned iterable: ListLiteral[Ts]) raises:
      constrained[N <= 32, "`size` of array must be less than 32"]()
      # if N != len(iterable):
      #    raise Error("`size` of `iterable` is not equal to the `size` of array")
      self.capacity = self.size * 2
      self.storage = stack_allocation[N*2, T]()
      let src: Pointer[T] = Pointer.address_of(iterable).bitcast[T]()
      alias Counter: Int = 0
      for i in range(len(iterable)):
         alias JustAnotherCounter = Counter
         alias Counter = comptime_add[JustAnotherCounter, 1]()
         self.check_size[Counter]()
         self.storage.store(i, src.load(i))

   fn __getitem__(self, idx: Int) raises -> T :
      if idx > self.size:
         raise Error("Out of bounds")
      return self.storage[idx]

   fn __setitem__(self, idx: Int, value: T) raises:
      if idx > self.size:
         raise Error("Out of bounds")
      self.storage.store(idx, value)

   fn __del__(owned self):
      if self.storage:
         self.storage.free()

from memory import stack_allocation

struct IntType[num: Int]:
   alias value: Int = num

fn comptime_add[NumOne: Int, NumTwo: Int]() -> Int:
   return NumOne + NumTwo

struct Array[T: AnyType, N: Int]:
   alias size: Int = N

   var capacity: Int
   var storage: Pointer[T]

   @staticmethod
   fn check_size[Size: Int]() raises -> Int:
      print("Size is ", Size)
      @parameter
      if Size <= N:
         return Size
      else:
         raise Error("`{Size}`")

   fn __init__[*Ts: AnyType](inout self, owned iterable: ListLiteral[Ts]) raises:
      constrained[N <= 32, "`size` of array must be less than 32"]()
      # if N != len(iterable):
      #    raise Error("`size` of `iterable` is not equal to the `size` of array")
      self.capacity = self.size * 2
      self.storage = stack_allocation[N*2, T]()
      let src: Pointer[T] = Pointer.address_of(iterable).bitcast[T]()
      alias Counter: Int = 0
      for i in range(len(iterable)):
         alias JustAnotherCounter = Counter
         alias Counter = comptime_add[JustAnotherCounter, 1]()
         self.check_size[Counter]()
         self.storage.store(i, src.load(i))

   fn __getitem__(self, idx: Int) raises -> T :
      if idx > self.size:
         raise Error("Out of bounds")
      return self.storage[idx]

   fn __setitem__(self, idx: Int, value: T) raises:
      if idx > self.size:
         raise Error("Out of bounds")
      self.storage.store(idx, value)

   fn __del__(owned self):
      if self.storage:
         self.storage.free()

Looks like its difficult to do compile time checking of array length lol, even though obviously at compile time the array is defined as [1, 2, 3, 4, 5, 7] with length of 6.

message.txt

Gaming

Programming

Error:cannot construct 'Array' from 'ListLiteral[Int, Int, Int, Int, Int]' value in 'var' initialize

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