Question:
"Certain properties of a programming language may require that the only way to get the code written in it be executed is by interpretation. In other words, compilation to a native machine code of a traditional CPU is not possible. What are these properties?"
Compilers: Principles and Practice by Parag H. Dave and Himanshu B. Dave (May 2, 2012)
The book gives no clue about the answer. I tried to find the answer on Concepts of Programming Languages (SEBESTA), but to no avail. Web searches were of little avail too. Do you have any clue?