141: Sidetrip

Note how strongly functions differ from macros:

• Functions are called at run time. Macros are expanded at compile time.
• Function parameters are typed. Macro parameters are not.
• Function arguments are evaluated, and copies of those values are assigned to parameters. Macro arguments are not evaluated; instead, they are viewed as text to be substituted for the macro's parameters before the real work of compilation begins.

Because macro parameters are replaced by text, macros are said to be handled as call-by-name parameters.