Windows Unicode

[89z]

Using a three byte character:

∞ (U+221E) (Alt + 236)

I can paste or enter with no problem:

PS D:\Desktop\ishell-master\example> .\example.exe
Sample Interactive Shell
>>> ∞
Error: Unknown rune: 8734
>>> ∞
Error: Unknown rune: 8734

but four byte character:

😀 (U+1F600)

Fails:

>>> ��
Error: Unknown rune: 65533
>>>