|
|
| Line 24: |
Line 24: |
| | | | |
| | | | |
| − | <h2 align="center">I ARITHMETIC COMMANDS</h2>
| |
| − | Commands that operate on variables:<br />
| |
| | | | |
| − | === increment(n); ===
| |
| − |
| |
| − | The value of the variable Var(n) is incremented by one, i.e.<br />
| |
| − | Var(n) = Var(n)+1. If the value is already 255, it is left unchanged.
| |
| − |
| |
| − | === decrement(n); ===
| |
| − |
| |
| − | The value of the variable Var(n) is decremented by one, i.e.<br />
| |
| − | Var(n) = Var(n)-1. If the value is 0, it is left unchanged.
| |
| − |
| |
| − | === assign(n, m); ===
| |
| − |
| |
| − | Variable Var(n) is assigned the value m, i.e. Var(n) = m
| |
| − |
| |
| − | === assignv(n, m); ===
| |
| − |
| |
| − | Variable Var(n) is assigned the value of Var(m), i.e.<br />
| |
| − | Var(n) = Var(m).
| |
| − |
| |
| − | === addn(n, m); ===
| |
| − |
| |
| − | The value of variable Var(n) is incremented by m, i.e.<br />
| |
| − | Var(n) = Var(n) + m.
| |
| − |
| |
| − | === addv(n, m); ===
| |
| − |
| |
| − | The value of variable Var(n) is incremented by the value of Var(m), i.e. Var(n) = Var(n) + m.<br />
| |
| − | [Now what happens in the above two commands on 8-bit overflow: does the result wrap over 0 or stays 255?<br />
| |
| − | I.e. is 250 + 10 == 4 or 250 + 10 == 255?]
| |
| − |
| |
| − | === subn(n, m); ===
| |
| − |
| |
| − | The value of Var(n) is decremented by m, I.e. Var(n) = Var(n) - m
| |
| − |
| |
| − | === subv(n, m); ===
| |
| − |
| |
| − | The value of Var(n) is decremented by Var(m), i.e. Var(n) = Var(n) - Var(m).<br />
| |
| − | [Again, what happens when the result must be negative: is<br />
| |
| − | 1 - 2 == 255 or 1 - 2 == 0?]
| |
| − |
| |
| − | === lindirectn(n, m); ===
| |
| − |
| |
| − | Variable Var(i) where i is the value of Var(n) is assigned a value m, i.e. Var(Var(n)) = m.
| |
| − |
| |
| − | === lindirectv(n, m); ===
| |
| − |
| |
| − | Variable Var(i) where i is the value of Var(n) is assigned the value of Var(m), i.e. Var(Var(n)) = Var(m).
| |
| − |
| |
| − | === rindirect(n, m); ===
| |
| − |
| |
| − | Variable Var(n) is assigned the value of Var(i) where i is the value of Var(m), i.e. Var(n) = Var(Var(m)).
| |
| − |
| |
| − | === muln(n, m); ===
| |
| − |
| |
| − | Variable Var(n) is multiplied by m, i.e. Var(n) = Var(n) * m.
| |
| − |
| |
| − | === mulv(n, m); ===
| |
| − |
| |
| − | Variable Var(n) is multiplied by the value of Var(m), i.e.<br />
| |
| − | Var(n) = Var(n) * Var(m).<br />
| |
| − | [What happens on overflow?]
| |
| − |
| |
| − | === divn(n, m) ===
| |
| − |
| |
| − | Variable Var(n) is divided by m, i.e. Var(n) = Var(n) / m.
| |
| − |
| |
| − | === divv(n, m) ===
| |
| − |
| |
| − | Variable Var(n) is divided by the value of Var(m),<br />
| |
| − | i.e. Var(n) = Var(n) / Var(m). [What happens on division by 0?]
| |
| − |
| |
| − | === random(n, m, k) ===
| |
| − |
| |
| − | Variable Var(k) is assigned a random value in the range between n and m. Now let us consider the commands changing flag values. Remember that a flag can only have a value 0 or 1.
| |
| − |
| |
| − | === set(n) ===
| |
| − |
| |
| − | flag(n) is set to 1.
| |
| − |
| |
| − | === set.v(n) ===
| |
| − |
| |
| − | flag(i), where i is the value of var (n), is set to 1. i.e.<br />
| |
| − | flag(var(n)) = 1.
| |
| − |
| |
| − | === reset(n) ===
| |
| − |
| |
| − | flag(n) is set to 0.
| |
| − |
| |
| − | === reset.v(n) ===
| |
| − |
| |
| − | flag(i), where i is the value of var (n), is set to 0, i.e.<br />
| |
| − | flag(var(n)) = 0.
| |
| − |
| |
| − | === toggle(n) ===
| |
| − |
| |
| − | flag(n) toggles its value.
| |
| − |
| |
| − | === toggle.v(n) ===
| |
| − |
| |
| − | flag(i), where i is the value of var (n), i.e. flag(var(n)), toggles is value.
| |
| | | | |
| | Page: | | Page: |
