do-external-symbols

(do-external-symbols (var [package [result]]) body...)

Evaluates the body once per external (exported) symbol of package -- the current package when omitted -- with var bound to the symbol, then evaluates result with var bound to nil and returns its value (nil when no result form is given). The symbols come in sorted order. Over cl it visits the standard's 978 external names -- the car/cdr compositions caar to cddddr among them -- and while.

This works on every backend: the interpreter reads its live registry, and the compiled backends answer from the package table baked in at compile time (plus any package a make-package call creates at run time). A return in the body exits the whole form -- the loop establishes the implicit nil block every iteration macro has -- skipping the result form.

The example builds packages of its own rather than walking a built-in one, so the whole set it visits is visible on the page. The pair is built the same way as the one do-symbols walks -- a base package that exports two names and a second package that uses it and exports two of its own -- so the two pages differ by exactly one rule: what a package INHERITS is not what it exports, and ASHARED and ZSHARED are absent here.