6.6.10.2 Dynamic Vector Creation and Validation

Instead of creating a vector implicitly by using the read syntax just described, you can create a vector dynamically by calling one of the vector and list->vector primitives with the list of Scheme values that you want to place into a vector. The size of the vector thus created is determined implicitly by the number of arguments given.

Scheme Procedure: vector arg …

Scheme Procedure: list->vector l

C Function: scm_vector (l)

Return a newly allocated vector composed of the given arguments. Analogous to list.

(vector 'a 'b 'c) ⇒ #(a b c)

The inverse operation is vector->list:

Scheme Procedure: vector->list v

C Function: scm_vector_to_list (v)

Return a newly allocated list composed of the elements of v.

(vector->list #(dah dah didah)) ⇒  (dah dah didah)
(list->vector '(dididit dah)) ⇒  #(dididit dah)

To allocate a vector with an explicitly specified size, use make-vector. With this primitive you can also specify an initial value for the vector elements (the same value for all elements, that is):

Scheme Procedure: make-vector len [fill]

C Function: scm_make_vector (len, fill)

Return a newly allocated vector of len elements. If a second argument is given, then each position is initialized to fill. Otherwise the initial contents of each position is unspecified.

C Function: SCM scm_c_make_vector (size_t k, SCM fill)

Like scm_make_vector, but the length is given as a size_t.

To check whether an arbitrary Scheme value is a vector, use the vector? primitive:

Scheme Procedure: vector? obj

C Function: scm_vector_p (obj)

Return #t if obj is a vector, otherwise return #f.

C Function: int scm_is_vector (SCM obj)

Return non-zero when obj is a vector, otherwise return zero.