Modular•14mo ago

newbie needs help with error messages

the code:

@register_passable("trivial")
struct Item:
    var name: StringLiteral
    var qty: Int

    fn __init__(inout self) -> Self:
        self.name = "Unnamed"
        self.qty = 0


fn main():
    var item = Item()

@register_passable("trivial")
struct Item:
    var name: StringLiteral
    var qty: Int

    fn __init__(inout self) -> Self:
        self.name = "Unnamed"
        self.qty = 0


fn main():
    var item = Item()

gives error

invalid call to '__init__': callee expects 1 argument, but 0 were specified

invalid call to '__init__': callee expects 1 argument, but 0 were specified

what should I do?

16 Replies

superfes•14mo ago

New here, but I don't get that error when running it.

ctOP•14mo ago

this is what I get

@register_passable("trivial")
struct Item:
    var name: StringLiteral
    var qty: Int

    fn __init__(inout self) -> Self:
        self.name = "Unnamed"
        self.qty = 0


fn main():
    var item: Item = Item()
    var ls = DynamicVector[Item]()
    ls.push_back(item)
    print(ls[0].name)
c@c:~/w/mojo-playground$ mojo hello.mojo 
hello.mojo:15:26: error: invalid call to '__init__': callee expects 1 argument, but 0 were specified
    var item: Item = Item()
                     ~~~~^~
hello.mojo:9:5: note: function declared here
    fn __init__(inout self) -> Self:
    ^
mojo: error: failed to parse the provided Mojo

@register_passable("trivial")
struct Item:
    var name: StringLiteral
    var qty: Int

    fn __init__(inout self) -> Self:
        self.name = "Unnamed"
        self.qty = 0


fn main():
    var item: Item = Item()
    var ls = DynamicVector[Item]()
    ls.push_back(item)
    print(ls[0].name)
c@c:~/w/mojo-playground$ mojo hello.mojo 
hello.mojo:15:26: error: invalid call to '__init__': callee expects 1 argument, but 0 were specified
    var item: Item = Item()
                     ~~~~^~
hello.mojo:9:5: note: function declared here
    fn __init__(inout self) -> Self:
    ^
mojo: error: failed to parse the provided Mojo

superfes•14mo ago

superfes•14mo ago

Weird

ctOP•14mo ago

mojo --version mojo 0.2.1 (64d14e85)

superfes•14mo ago

I did in fact not have 0.2.1 installed Sorry

ctOP•14mo ago

do you have a newer version?

superfes•14mo ago

Older Just ran the install function again

ctOP•14mo ago

does it download the 350MB or so or is it smart about it?

superfes•14mo ago

Heh, I dunno how much it downloaded

ctOP•14mo ago

This is what I got now:

@register_passable("trivial")
struct Item:
    var name: StringLiteral
    var qty: Int

    fn __init__(inout self) -> Self:
        return Self {name: "Unnamed", qty: 0}


fn main():
    var item = Item()
    var ls = DynamicVector[Item]()
    ls.push_back(item)
    print(ls[0].name)
    print(ls[0].qty)

@register_passable("trivial")
struct Item:
    var name: StringLiteral
    var qty: Int

    fn __init__(inout self) -> Self:
        return Self {name: "Unnamed", qty: 0}


fn main():
    var item = Item()
    var ls = DynamicVector[Item]()
    ls.push_back(item)
    print(ls[0].name)
    print(ls[0].qty)

error:

error: invalid call to '__init__': callee expects 1 argument, but 0 were specified
    var item = Item()

error: invalid call to '__init__': callee expects 1 argument, but 0 were specified
    var item = Item()

superfes•14mo ago

Just FYI, when I get rid of the parens for var item = Item() it complains about something else error: return expected at end of function with results Which I assume is what you're after?

ModularBot•14mo ago

Congrats @superfes, you just advanced to level 1!

ctOP•14mo ago

I think the parens are necessary and should call the __init__ with "self" being provided

ModularBot•14mo ago

Congrats @ct, you just advanced to level 2!

ctOP•14mo ago

Ok. https://docs.modular.com/mojo/programming-manual.html#register_passable-struct-decorator Notice that __init__ does not need 'self'

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newbie needs help with error messages