progv

(progv symbols values body...)

Evaluates symbols and values (each a list), then dynamically binds each symbol to the corresponding value for the duration of body, restoring the previous values on exit. When values is shorter than symbols, the extra symbols are bound to nil. Unlike let, the symbols are computed at runtime and need not have been proclaimed special. Returns the value of the last body form.

progv is supported on the interpreter only; the JVM and WASM compilers reject it (the bound symbols are not known at compile time, so their storage cannot be named).