Primitives

A primitive procedure is a built-in procedure that is implemented in low-level language. Not all built-in procedures (see section 9.3.1) are primitives, but almost all R⁵RS procedures are primitives, as are most of the procedures described in this manual (except for MzLib procedures).

• (primitive? v) returns #t if v is a primitive procedure or #f otherwise.
• (primitive-name prim-proc) returns the name of the primitive procedure prim-proc as a string.
• (primitive-result-arity prim-proc) returns the arity of the result of the primitive procedure prim-proc (as opposed to the procedure's input arity as returned by arity; see section 4.10.1). For most primitives, this procedure returns 1 since most primitives return a single value when applied. For information about arity values, see section 4.10.1.
• (primitive-closure? v) returns #t if v is internally implemented as a primitive closure rather than an simple primitive procedure, #f otherwise. This information is intended for use by the mzc compiler.
• (simple-return-primitive? prim-proc) returns #t if the given primitive procedure never computes its return value by an internal chained tail call. This information is intended for use by the mzc compiler.