86 lines
2.2 KiB
Rust
86 lines
2.2 KiB
Rust
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use crate::{parse, Instruction, Operation, ParseError, Parser, Value, ValueError};
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pub fn run(input: &str) -> Result<Option<Value>, VmError> {
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let instructions = parse(input)?;
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let vm = Vm::new(instructions);
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vm.run()
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}
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pub struct Vm {
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instructions: Vec<Instruction>,
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}
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impl Vm {
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pub fn new(instructions: Vec<Instruction>) -> Self {
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Vm { instructions }
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}
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pub fn run(&self) -> Result<Option<Value>, VmError> {
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let mut previous_value = None;
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for instruction in &self.instructions {
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previous_value = self.run_instruction(instruction)?;
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}
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Ok(previous_value)
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}
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fn run_instruction(&self, instruction: &Instruction) -> Result<Option<Value>, VmError> {
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match &instruction.operation {
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Operation::Add(instructions) => {
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let left = if let Some(value) = self.run_instruction(&instructions.0)? {
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value
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} else {
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return Err(VmError::ExpectedValue(instructions.0.operation.clone()));
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};
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let right = if let Some(value) = self.run_instruction(&instructions.1)? {
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value
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} else {
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return Err(VmError::ExpectedValue(instructions.1.operation.clone()));
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};
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let sum = left.add(&right)?;
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Ok(Some(sum))
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}
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Operation::Assign(_) => todo!(),
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Operation::Constant(value) => Ok(Some(value.clone())),
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Operation::Identifier(_) => todo!(),
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Operation::List(_) => todo!(),
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Operation::Multiply(_) => todo!(),
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}
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}
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}
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#[derive(Clone, Debug, PartialEq)]
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pub enum VmError {
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ExpectedValue(Operation),
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InvalidOperation(Operation),
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ParseError(ParseError),
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ValueError(ValueError),
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}
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impl From<ParseError> for VmError {
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fn from(v: ParseError) -> Self {
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Self::ParseError(v)
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}
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}
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impl From<ValueError> for VmError {
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fn from(v: ValueError) -> Self {
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Self::ValueError(v)
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}
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn add() {
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let input = "1 + 2";
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assert_eq!(run(input), Ok(Some(Value::integer(3))));
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}
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}
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