Accessing active symbol table in Common Lisp

Question

I have heard that the active symbol table is accessible within the Common Lisp runtime. Have I misunderstood?

What do you mean by "active symbol table"? – dmitry_vk Sep 20 '10 at 03:19 — dmitry_vk, Sep 20 '10 at 03:19

Rainer Joswig · Accepted Answer · 2010-09-20T07:25:01.883

8

'Symbol tables' are called 'packages' in Common Lisp. See for example: Introduction to Packages, CL HyperSpec.

Several operations over packages are available in Common Lisp: The Packages Dictionary.

Symbols can be members of packages (being 'interned').

The variable *package* holds a package as a value, which is used by several operations that use a package as a default. An example is the 'reader', which by default does a look up in the package of *package*.

edited Sep 20 '10 at 07:25

answered Sep 20 '10 at 07:19

Rainer Joswig

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ohhh so that's where perl packages come from, and why all typeglobs which are entries are always bound to a package O.o – Dmytro Nov 11 '16 at 07:16

score 5 · Answer 2 · edited May 23 '17 at 11:53

5

You can use do-all-symbols.

See here for a similar question. The accepted answer has some details on packages also, which is handy.

Something like this in code. Define useful-symbol-p as you see fit:

(let ((lst ()))
   (do-all-symbols (s lst)
     (when (useful-symbol-p s) (push s lst)))
   lst)

edited May 23 '17 at 11:53

Community

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answered Sep 20 '10 at 02:12

clstrfsck

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Accessing active symbol table in Common Lisp

2 Answers2