59 lines
1.6 KiB
Rust
59 lines
1.6 KiB
Rust
use std::rc::Rc;
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use super::{Environment, Node, NodeEnum, Precedence, constant::Constant};
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#[derive(Clone, Debug, PartialEq, PartialOrd)]
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pub struct Subtract {
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left: Rc<NodeEnum>,
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right: Rc<NodeEnum>,
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}
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impl Node for Subtract {
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fn evaluate(&self, env: &mut super::Environment) -> Result<Rc<super::NodeEnum>, String> {
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let evaluated_left = self.left.evaluate(env)?;
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let evaluated_right = self.right.evaluate(env)?;
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match (evaluated_left.as_ref(), evaluated_right.as_ref()) {
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(NodeEnum::Constant(a), NodeEnum::Constant(b)) => {
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Ok(Rc::new(Constant::new(a.get_value() - b.get_value()).into()))
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}
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_ => Err(format!("Invalid Add operation: {:?}", self)),
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}
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}
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fn as_string(&self, env: Option<&Environment>) -> String {
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let left_string = if self.left.precedence() <= self.precedence() {
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format!("({})", self.left.as_string(env))
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} else {
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self.left.as_string(env)
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};
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let right_string = if self.right.precedence() <= self.precedence() {
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format!("({})", self.right.as_string(env))
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} else {
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self.right.as_string(env)
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};
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format!("{}-{}", left_string, right_string)
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}
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fn precedence(&self) -> Precedence {
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Precedence::Term
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}
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}
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impl Subtract {
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pub fn new(left: NodeEnum, right: NodeEnum) -> Self {
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Self {
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left: Rc::new(left),
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right: Rc::new(right),
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}
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}
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pub fn get_left(&self) -> Rc<NodeEnum> {
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self.left.clone()
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}
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pub fn get_right(&self) -> Rc<NodeEnum> {
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self.right.clone()
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}
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}
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