Package systems a special case of first class functions
SICP Lecture 7B makes a great point during the second Q&A session about solving modularity and abstraction problems by reorganizing a solution around PGEN which parametrizes a general algorithm for a specific input.
Early in the book, the similarity of class based object systems and package management systems with Scheme style first class functions kept peaking my interest. Sussman points out that first-class functions can solve modularity issues in the general case with a very simple minimal mechanism. Without first class functions, one can solve specific known problems without special language features such as packages, modules, etc.
One case the immediately comes to mind is the Java language feature of anonymous inner classes for getting around certain awkward pieces of code ( usually introduced by static typing requirements ).
Early in the book, the similarity of class based object systems and package management systems with Scheme style first class functions kept peaking my interest. Sussman points out that first-class functions can solve modularity issues in the general case with a very simple minimal mechanism. Without first class functions, one can solve specific known problems without special language features such as packages, modules, etc.
One case the immediately comes to mind is the Java language feature of anonymous inner classes for getting around certain awkward pieces of code ( usually introduced by static typing requirements ).