ANSI Common Lisp   2 Syntax   2.4 Standard Macro Characters   2.4.8 Sharpsign

2.4.8.6 Sharpsign Dot

#.foo is read as the object resulting from the evaluation of the object represented by foo. The evaluation is done during the read process, when the #. notation is encountered. The #. syntax therefore performs a read-time evaluation of foo.

The normal effect of #. is inhibited when the value of *read-eval* is false. In that situation, an error of type reader-error is signaled.

For an object that does not have a convenient printed representation, a form that computes the object can be given using the #. notation.