eval

(eval expr) (eval expr environment)

Evaluates the datum expr at run time and returns its value. Every environment specifier -- (interaction-environment), (environment ...), (scheme-report-environment 5), user-initial-environment, system-global-environment -- names the one global environment, and the argument may be left out (R7RS requires it, and so does --scheme-standard r7rs). A define inside eval creates a program global. define-record-type, define-values, let-values and import are refused inside eval. See eval for the full semantics.