nlfiedler
commented
10 years ago See section 7.3 of R7RS for a complete listing of the Scheme code to implement all of these expressions: cond, case, and, or, when, unless, let, let, letrec, letrec, let-values, let*-values, define-values, do, delay-force, delay, make-promise, make-parameter, parameterize, guard, case-lambda, cond-expand.
The only requirement is hygienic macro support.
See section 4.2 of R7RS for a complete list of the standard derived expressions expected in Scheme. This includes, but is not limited to, cond, case, and, or, when, unless, let and friends, begin, do, delay, force, etc.