[siraben]

Yes, to type a TI-BASIC program you have to go through the calculator menus which directly insert the tokenized input into the buffer.

The weird thing about TI-BASIC is how seemingly innocent changes in the input can cause huge performance regressions e.g. https://siraben.github.io/ti84p-re/sub-tibasic-for-paren.htm...

  For(I,1,N
  If 0
  1
  End

is much slower than

  For(I,1,N)
  If 0
  1
  End

[asveikau]

The open paren being part of the tokens was always weird. I could imagine that doing strange things for the parser; when it sees a close paren it needs to know that several of the preceding tokens may have an open paren even without having a '(' token.