Length of the array returned from __newArray.

[synxroform]

Maybe i miss something, but for arrays created with __newArray, value of length is always 44. For example ...

test.ts

export function test_length(arr: f64[]) : i32 {
    return arr.length;
}
export const F64A = idof<Float64Array>()

test.js

let arr = m.__retain(m.__newArray(m.F64A, [1, 2, 3, 4, 5]))
console.log(m.test_length(arr))
m.__release(arr)

output is 44

This is not the case for arrays created within AssemblyScript and returned as pointers.

[MaxGraey]

I guess this should be fixed after #1586

[dcodeIO]

The code snippet is mixing two incompatible types: Array<f64> (with a mutable .length) and Float64Array (with a fixed .length that is computed). Try to change F64A to idof<f64[]> or arr's type to Float64Array so both are the same. Let me know if that fixes it :)

[MaxGraey]

@dcodeIO nice catch. Playgrpund which demonstrate proper work: https://bit.ly/3msIzq3

[synxroform]

Yes, changing export const F64A = idof<f64[]>() fixes issue. But what type is proper for ordinary javascript arrays ?

[dcodeIO]

If resizing the array is not necessary, Float64Array should be slightly more efficient. An Array<f64> for example does a check for whether it needs to resize the backing buffer when assigning an element, which Float64Array does not need.

Most efficient one is StaticArray<f64> that is quite similar to a plain C array, since it doesn't even maintain a backing buffer with indirection.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.