Can not using map to apply function

[NinjaCats]

Describe the bug
When using map to apply a function to fields does not work, list comprehension works well.

To Reproduce

# %%
import taichi as ti

ti.init(ti.gpu)

# %%
@ti.kernel
def random_fill(x:ti.template()):
    for I in ti.grouped(x):
        x[I] = ti.random()

x = ti.field(ti.f16, 4)
y = ti.field(ti.f16, (2, 4))

map(random_fill, [x, y])
print(x, y)
[random_fill(x) for x in [x, y]]
print(x, y)

Log/Screenshots

[Taichi] version 1.7.0, llvm 15.0.1, commit 2fd24490, win, python 3.10.13
[Taichi] Starting on arch=cuda
[0. 0. 0. 0.] [[0. 0. 0. 0.]
 [0. 0. 0. 0.]]
[0.0903 0.6514 0.3926 0.7803] [[0.7163  0.359   0.506   0.6934 ]
...

[Ives0721]

The map function in Python would only return a map object (actually a iterator). If you want to execute every object, yield every object inside iterator. The simplest way is: turn the map object into a list.

So your example code may look like this

import taichi as ti

ti.init(arch=ti.gpu)

# %%
@ti.kernel
def random_fill(x: ti.template()):
    for I in ti.grouped(x):
        x[I] = ti.random()

x = ti.field(ti.f16, 4)
y = ti.field(ti.f16, (2, 4))

_ = list(map(random_fill, [x, y]))
print(x, y)

And here's my output:

[Taichi] version 1.6.0, llvm 15.0.1, commit f1c6fbbd, win, python 3.9.16
[Taichi] Starting on arch=cuda
[0.0903 0.6514 0.3926 0.7803] [[0.7163  0.359   0.506   0.6934 ]
 [0.03262 0.3179  0.05496 0.4727 ]]