Vectors

(vector n) creates a (standard) vector with n element numbered from 1 to n. For standard vectors the zeroth address holds an integer that gives the size of the vector. The shortest standard vector is created by expression (vector 0) which creates a standard vector whose zeroth address contains the object zero. This called the empty vector and Shen permits the user to write <> as shorthand for the empty vector.

The polyadic @v adds n elements in order to a vector, copying it and creating a new vector.

(<-vector v n) (n >= 1) accesses the nth element of vector v. The function limit accesses the 0th element of a vector v.

(vector-> v n x) destructively modifies v by placing x in the nth address of v.

A 2-dimensional array is simply a vector of vectors.

The non-destructive operation (@v x v) creates a new vector v' whose tail is the same as v and whose head is x.

(1-) (set *myvector* (@v 1 <>))
<1> {create a vector with 1 element}

(2-) (limit (value *myvector*))
1

(3-) (set *myvector* (@v 0 (value *myvector*)))
<0 1>

(4-) (limit (value *myvector*))
2

(5-) (@v -1 (value *myvector*))
<-1 0 1>

(6-) (limit (value *myvector*))
2

(7-) (<-vector (value *myvector*) 2)
1

(8-) (vector-> (value *myvector*) 2 a)
<0 a>

(9-)(value *myvector*)
<0 a>

See also pattern matching in the fast reference.

• Shen official standard