do*

(do* ((var init step?)...) (end-test result...) body...)

Like do, but the bindings and steps are sequential (let*-style) rather than parallel: each init form sees the variables bound earlier in the same list, and each step form sees the variables already updated this iteration. Otherwise it behaves identically -- end-test is checked before each pass, the result forms supply the return value, and return exits early. In the example below j is initialised from the freshly bound i, which a plain do could not do.