Assigning variables

We can assign values to variables at runtime. Try running the following:

sentient ten.snt --assign '{ a: 5 }'

This will run the same program as before but with an added constraint that the value of ‘a’ must be 5. This means that you can write a generic program that solves some problem and then assign some of its variables at runtime to suit your needs.

For example, you might write a generic program for solving Sudoku puzzles. You could then assign some of its variables at runtime for each of the numbers you know about. Sentient will then solve the puzzle with those constraints set.

For our ‘Hello world’ program, we could make it more generic! Instead of hardcoding the total to 10, let’s introduce a ‘target’ and assign it at runtime:

int a, b, c, target;

invariant a + b + c == target;
invariant a > 0, b > 0, c > 0;

expose a, b, c, target;

sentient ten.snt --assign '{ target: 15 }'

Perhaps we should rename our program to something more appropriate!