loop Macro

Summary

Add iteration on the result of a SQL query.

Package

common-lisp

Signature

loop

Description

The macro loop has been extended to allow iteration over the result of a SQL query. See Loop Extensions in Common SQL in the Common SQL chapter for details.

Notes about the LispWorks implementation of loop:

1. The standard is inconsistent, because 6.1.2.1 Iteration Control includes repeat in the list that "must precede any other loop clauses" even though the rest of that section is about for clauses.

   Also, the description of repeat in 6.1.4 Termination Test Clauses makes repeat sound more like an interation clause because its form is evaluated once and it does some work before the body rather than being interleaved with other body forms ("If the expression evaluates to 0 or to a negative number, the loop body is not evaluated.").

   In LispWorks, the repeat clause must obey the rules in section 6.1.2.1 Iteration Control. In particular the repeat clause must precede loop body clauses. To write portable code that uses repeat with other iteration clauses, we recommend putting the repeat as the final iteration clause so it can also be regarded as the first of the main-clauses, which makes it match both the syntax as described in the entry for loop and the text of sections section 6.1.2.1 Iteration Control and 6.1.4 Termination Test Clauses.

See also

loop in the Common Lisp HyperSpec