To invent programs, you need to be able to capture abstractions and ex
design. It’s the job of a programming language to help you do this. The
process of invention and design by letting you encode abstractions tha
It should let you make your ideas concrete in the code you write. Surf
the architecture of your program.
All programming languages provide devices that help express abstrac
are ways of grouping implementation details, hiding them, and giving
a common interface—much as a mechanical object separates its interfa
illustrated in “Interface and Implementation” .
Figure 2-1 Inte rfa ce a nd Im ple m e nta tion