Modular•14mo ago

How to store Struct(or string) into DynamicVector

I want to store struct into DynamicVector at first I tried

from utils.vector import DynamicVector


struct Person:
    var first: String
    var last: String
    var id: Int

    fn __init__(inout self, n: String, l: String, id: Int):
        self.first = n
        self.last = l
        self.id = id


fn main() raises:
    var x = DynamicVector[Person]()
    let me = Person("A", "B", 1)
    x.push_back(me)

from utils.vector import DynamicVector


struct Person:
    var first: String
    var last: String
    var id: Int

    fn __init__(inout self, n: String, l: String, id: Int):
        self.first = n
        self.last = l
        self.id = id


fn main() raises:
    var x = DynamicVector[Person]()
    let me = Person("A", "B", 1)
    x.push_back(me)

then I tried to change String Pointer[UInt8] now I do not know how to load string into Pointer[UInt8]

from utils.vector import DynamicVector

alias PointerString = Pointer[UInt8]
alias PointerStrings = Pointer[PointerString]
alias BufferPtrType = DTypePointer[DType.uint8]


@value
@register_passable("trivial")
struct Person:
    var id: Int
    var first: PointerString
    var last: PointerString

    fn __init__(inout self, id: Int, f: PointerString, l: PointerString) -> Self:
        self.id = id
        self.first = f
        self.last = l
        return self


fn main() raises:
    var x = DynamicVector[Person]()
    let first = PointerString.alloc(100)
    first.store(0, 12)
    let last = PointerString.alloc(100)
    last.store(0, 17)
    let id = 1
    let me = Person(id, first, last)
    x.push_back(me)

from utils.vector import DynamicVector

alias PointerString = Pointer[UInt8]
alias PointerStrings = Pointer[PointerString]
alias BufferPtrType = DTypePointer[DType.uint8]


@value
@register_passable("trivial")
struct Person:
    var id: Int
    var first: PointerString
    var last: PointerString

    fn __init__(inout self, id: Int, f: PointerString, l: PointerString) -> Self:
        self.id = id
        self.first = f
        self.last = l
        return self


fn main() raises:
    var x = DynamicVector[Person]()
    let first = PointerString.alloc(100)
    first.store(0, 12)
    let last = PointerString.alloc(100)
    last.store(0, 17)
    let id = 1
    let me = Person(id, first, last)
    x.push_back(me)

6 Replies

NKspartan•14mo ago

you can do it using pointers:

var myVector = DynamicVector[Pointer[MyStruct]] ()
var myStructInstance = MyStruct(1, 2)
var hello = __get_lvalue_as_address(myStructInstance) # Get address of value

myVector.push_back(hello)
print(__get_address_as_lvalue(myVector[0].address).field2) # get the address of the value and then convert it to a reference (lvalue)

var myVector = DynamicVector[Pointer[MyStruct]] ()
var myStructInstance = MyStruct(1, 2)
var hello = __get_lvalue_as_address(myStructInstance) # Get address of value

myVector.push_back(hello)
print(__get_address_as_lvalue(myVector[0].address).field2) # get the address of the value and then convert it to a reference (lvalue)

Michael K•14mo ago

There is also the example in llama2.mojo:

fn str_to_ptr(s: String) -> PointerString:
    let ret = PointerString.alloc(len(s) + 1)
    for i in range(len(s)):
        ret.store(i, ord(s[i]))
    ret.store(len(s), 0)
    return ret

fn str_to_ptr(s: String) -> PointerString:
    let ret = PointerString.alloc(len(s) + 1)
    for i in range(len(s)):
        ret.store(i, ord(s[i]))
    ret.store(len(s), 0)
    return ret

PointerString is the same alias (Pointer[UInt8]) in that repo as in your example here.

GitHub

llama2.mojo/llama2.mojo at master · tairov/llama2.mojo

Inference Llama 2 in one file of pure 🔥. Contribute to tairov/llama2.mojo development by creating an account on GitHub.

ModularBot•14mo ago

Congrats @Michael K, you just advanced to level 1!

Geo7OP•14mo ago

Thanks for the responses, I tried @NKspartan example and it is working, But when I tried to write 2 helper function it does not work anymore what I've done wrong?

struct Person:
    var id: Int
    var name: String

    fn __init__(inout self, i: Int, n: String):
        self.id = i
        self.name = n

    fn __copyinit__(inout self, borrowed other: Self):
        self.id = other.id
        self.name = other.id


fn append(inout v: DynamicVector[Pointer[Person]], owned p: Person):
    let _tmp = __get_lvalue_as_address(p)
    v.push_back(_tmp)


fn get(inout v: DynamicVector[Pointer[Person]], index: Int) -> Person:
    let _tmp = __get_address_as_lvalue(v[index].address)
    return _tmp


fn main():
    var v = DynamicVector[Pointer[Person]]()
    let p1 = Person(1, "George")
    let p2 = Person(2, "Rose")
    append(v, p1)
    append(v, p2)
    let p = get(v, 0)
    print(p.name) # It is printing id instead of name !!!

struct Person:
    var id: Int
    var name: String

    fn __init__(inout self, i: Int, n: String):
        self.id = i
        self.name = n

    fn __copyinit__(inout self, borrowed other: Self):
        self.id = other.id
        self.name = other.id


fn append(inout v: DynamicVector[Pointer[Person]], owned p: Person):
    let _tmp = __get_lvalue_as_address(p)
    v.push_back(_tmp)


fn get(inout v: DynamicVector[Pointer[Person]], index: Int) -> Person:
    let _tmp = __get_address_as_lvalue(v[index].address)
    return _tmp


fn main():
    var v = DynamicVector[Pointer[Person]]()
    let p1 = Person(1, "George")
    let p2 = Person(2, "Rose")
    append(v, p1)
    append(v, p2)
    let p = get(v, 0)
    print(p.name) # It is printing id instead of name !!!

Michael K•14mo ago

In __copyinit__ you have self.name = other.id. This should be self.name = other.name.

Geo7OP•14mo ago

Thanks a lot, silly mistake 🙂

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How to store Struct(or string) into DynamicVector