use serde::{Deserialize, Serialize}; use tree_sitter::Node; use crate::{AbstractTree, Error, Result, Value, VariableMap}; use super::{identifier::Identifier, statement::Statement}; #[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)] pub struct Assignment { identifier: Identifier, operator: AssignmentOperator, statement: Statement, } #[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)] pub enum AssignmentOperator { Equal, PlusEqual, MinusEqual, } impl AbstractTree for Assignment { fn from_syntax_node(source: &str, node: Node) -> Result { let identifier_node = node.child(0).unwrap(); let identifier = Identifier::from_syntax_node(source, identifier_node)?; let operator_node = node.child(1).unwrap().child(0).unwrap(); let operator = match operator_node.kind() { "=" => AssignmentOperator::Equal, "+=" => AssignmentOperator::PlusEqual, "-=" => AssignmentOperator::MinusEqual, _ => { return Err(Error::UnexpectedSyntaxNode { expected: "=, += or -=", actual: operator_node.kind(), location: operator_node.start_position(), relevant_source: source[operator_node.byte_range()].to_string(), }) } }; let statement_node = node.child(2).unwrap(); let statement = Statement::from_syntax_node(source, statement_node)?; Ok(Assignment { identifier, operator, statement, }) } fn run(&self, source: &str, context: &mut VariableMap) -> Result { let key = self.identifier.inner().clone(); let mut value = self.statement.run(source, context)?; match self.operator { AssignmentOperator::PlusEqual => { if let Some(previous_value) = context.get_value(&key)? { value += previous_value } } AssignmentOperator::MinusEqual => { if let Some(previous_value) = context.get_value(&key)? { value -= previous_value } } AssignmentOperator::Equal => {} } context.set_value(key, value)?; Ok(Value::Empty) } }