HW3 Q5.

(a)

It is easier to manage state explicitly in imperative languages.

For many programming tasks involving input/output, side effects are
just as important as the result of a computation.

Languages that support higher-level functions and garbage collection
impose costs on programs that don't use these features.

It is more difficult to use a language with garbage collection for
performance-critical tasks where it is important to control memory
management at a low level.

(b)

It is easier to implement imperative languages than functional
languages on machines with limited disk and memory sizes.

Compilers for such languages can be less complicated, because the
elements of the language can translate more directly into machine
instructions.

(c)

Functional languages require bigger executables (or bigger library
functions) because runtime support is needed for higher-level
functions and garbage collection.

(d)

In the days when every byte counted for even simple programs,
imperative languages were much more practical than functional
languages.

(e)

For some applications, these concerns are no longer important, but
there are still many applications for which utilizing the hardware to
the fullest is important.  Also, some aspects of hardware performance
(like hard disk and DRAM latencies) are not improving nearly as
quickly as others, so in some cases it is even more important to give
programmers control over how resources are used.