7. Statements
7.1. Declaration
VCalc adds vectors as an assignable type. To declare a vector
variable, you declare a variable as you would an integer, but replace
int with vector. Vectors may be initialized with any expression
that returns a vector. For example, assigning a range to a vector v:
vector v = 1..10;
print(v);
prints the following:
[1 2 3 4 5 6 7 8 9 10]
7.2. Assignment
There are a few new important points when dealing with assignments.
The size of a vector may change while the program is executing if a vector variable is assigned another value. For instance, the following sequence of statements is valid:
vector v = 1..10; v = 1..1000;
You will have to allocate more memory to store the result of the assignment.
The type of the expression of the assignment must match the destination variable’s type. This is apparent for trying to assign vectors to a scalar. In the case of scalars being assigned to vectors, one might expect that we can use our extension policy to copy our scalar to every index of a newly created vector but the question is, how large is the new vector. Because that is indeterminable, this is not allowed. For example, the following sequence of statements is not valid:
int i = 1..3; vector v = 1;
Many languages allow you to assign to vector indices, VCalc does not. For example, the following sequence of statments is not valid:
vector v = 1..3; v[0] = 99;
7.3. Conditional
Conditional conditions must evaluate to booleans, which means that vectors are not a valid condition. Remember, however, that integers can be implicitly downcast to booleans.
7.4. Loops
Loop conditions must evaluate to booleans, which means that vectors are not a valid condition. Remember, however, that integers can be implicitly downcast to booleans.
7.5. Print
The print statement in VCalc behaves the same as SCalc for integers,
but must be extended to print vectors. All the elements of the vector are
printed on a single line between the opening anc closing brackets.
For example:
print(1..10);
prints the following:
[1 2 3 4 5 6 7 8 9 10]
The output of print is standardized to ensure everyone can pass everyone’s
tests. Follow these specifications:
There must be a new line after each
printstatement’s printed value.There must not be any trailing space after printed value and before the newline.
There must be an empty line at the end of your output.
There must not be spaces between the first and last number and the accompanying brackets in a vector.
There must be spaces between the numbers in a vector.
There must not be anything except spaces between the numbers in a vector.