7.8. Vectors

Vectors are language supported objects that allow for dynamically sized arrays. Once created, vectors in Gazprea behave exactly like arrays: they can be intermixed with arrays in expressions; they can be used on the RHS of array declarations and initializations; and they can be passed as array arguments to subroutines and functions.

7.8.1. Declaration

Vectors are declared and (optionally) initialized as follows. (Note that we have replaced <> with | in the notation below since the literals < and > are used in the declaration)

vector<|type|> |identifier|;
vector<|type|> |identifier| = |type-expr|;
vector<|type|> |identifier| = |type-array|;

Unlike the array type, Gazprea vectors do not have an explicit size specifier, often called capacity in other languages.

vector<character> vec = ['a', 'b', 'c'];
var vector<integer> ivec;
vector<real[*]> ragged_right = [[1.0], [2.0, 2.0]];
const vector<character> const_vec = vec;

As a language supported object, Gazprea provides several methods for vector:

• push() - pushes a new element to the back of the vector

• len() - number of elements in the vector

• append - append another array slice to the vector

  var vector<tuple(bool, integer)> tvec;
  tvec.push((false, 0));
  tvec.append((true, 1));
  tvec[tvec.len()] -> std_output; // prints (true, 1)
  

7.8.2. Operations

Operations on vectors are identical syntactically and semantically to operations on arrays. In particular, operand lengths must match for binary expressions and dot product.

A vector or vector slice can be passed as a call argument that has been declared as an array slice of the same size and type.

When indexing a vector of arrays, the first index selects the array element within the vector, and the second index selects the element within the array:

vector<real[*]> ragged_right = [[1.0], [2.1, 1.2]];
length(ragged_right[1]) -> std_output; // prints 1
ragged_right[2][2] -> std_output; // prints 1.2