@ti.func type hint error when using vector type

[neozhaoliang]

To reproduce:

import taichi as ti
ti.init()

vec4d = ti.types.vector(4, float)
v = vec4d(1, 2, 3, 4)

@ti.func
def length(w: vec4d):
    return w.norm()

@ti.kernel
def test():
    print(length(v))

test()

It reports error

Argument w of type <taichi.lang.matrix.VectorType object at 0x7f9954126d40> is expected to be a Matrix, but got <class 'taichi.lang.matrix.Vector'>.

[jim19930609]

It fails because you're directly using a python-scope Matrix v in Taichi kernel. To make it work, either pass v through the kernel arguments:

import taichi as ti
ti.init()

vec4d = ti.types.vector(4, float)
v = vec4d(1, 2, 3, 4)

@ti.func
def length(w: vec4d):
    return w.norm()

@ti.kernel
def test(x: vec4d):
    print(length(x))

test(v)

Or define v inside the kernel:

import taichi as ti
ti.init()

vec4d = ti.types.vector(4, float)

@ti.func
def length(w: vec4d):
    return w.norm()

@ti.kernel
def test():
    v = vec4d(1, 2, 3, 4)
    print(length(x))

test()

[neozhaoliang]

Just checked that the code works in v1.3.0 and fails for v1.4.0

[jim19930609]

hmmm, let me dig into this further