[2016][rust][12.0] Increment

profile
Alpha Chen 8 years ago
parent 499d8d13e5
commit b457ce5027

@ -18,7 +18,7 @@ enum Register {
enum Variable { enum Variable {
Register(Register), Register(Register),
Value(usize), Value(isize),
} }
#[derive(Debug, PartialEq)] #[derive(Debug, PartialEq)]
@ -33,7 +33,7 @@ impl State {
&Variable::Register(ref r) => { &Variable::Register(ref r) => {
self.registers.get(r).cloned().unwrap_or(0 as isize) self.registers.get(r).cloned().unwrap_or(0 as isize)
} }
&Variable::Value(value) => value as isize, &Variable::Value(value) => value,
} }
} }
} }
@ -58,12 +58,30 @@ impl Copy {
} }
// inc x increases the value of register x by one. // inc x increases the value of register x by one.
struct Increment {
register: Register,
}
impl Increment {
fn run(&self, state: &State) -> State {
let pc = state.pc + 1;
let mut registers = state.registers.clone();
let register = self.register.clone();
let value = state.value(&Variable::Register(self.register.clone())) + 1;
registers.insert(register, value);
State {
pc: pc,
registers: registers,
}
}
}
// dec x decreases the value of register x by one. // dec x decreases the value of register x by one.
// jnz x y jumps to an instruction y away (positive means forward; negative means backward), but only if x is not zero. // jnz x y jumps to an instruction y away (positive means forward; negative means backward), but only if x is not zero.
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {
use super::{Variable, Register, State, Copy}; use super::{Variable, Register, State, Copy, Increment};
#[test] #[test]
fn test_state_value() { fn test_state_value() {
@ -95,4 +113,19 @@ mod tests {
assert_eq!(copy.run(&state), expected); assert_eq!(copy.run(&state), expected);
} }
#[test]
fn test_increment() {
let increment = Increment { register: Register::A };
let state = State {
pc: 0,
registers: vec![(Register::A, 41)].into_iter().collect(),
};
let expected = State {
pc: 1,
registers: vec![(Register::A, 42)].into_iter().collect(),
};
assert_eq!(increment.run(&state), expected);
}
} }

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