use serde::{Deserialize, Serialize}; use tree_sitter::Node; use crate::{AbstractTree, Error, Identifier, Map, Result, Statement, Type, TypeDefinition, Value}; #[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)] pub struct Assignment { identifier: Identifier, type_definition: Option, 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, context: &Map) -> Result { Error::expect_syntax_node(source, "assignment", node)?; let child_count = node.child_count(); let identifier_node = node.child(0).unwrap(); let identifier = Identifier::from_syntax_node(source, identifier_node, context)?; let identifier_type = identifier.expected_type(context)?; let type_node = node.child(1); let type_definition = if let Some(type_node) = type_node { if type_node.kind() == "type_definition" { Some(TypeDefinition::from_syntax_node( source, type_node, context, )?) } else { context .variables()? .get(identifier.inner()) .map(|(_, r#type)| TypeDefinition::new(r#type.clone())) } } else { None }; let operator_node = node.child(child_count - 2).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(child_count - 1).unwrap(); let statement = Statement::from_syntax_node(source, statement_node, context)?; let statement_type = statement.expected_type(context)?; if let Some(type_definition) = &type_definition { match operator { AssignmentOperator::Equal => { type_definition .inner() .check(&statement_type) .map_err(|error| error.at_node(statement_node, source))?; } AssignmentOperator::PlusEqual => { if let Type::List(item_type) = type_definition.inner() { item_type .check(&statement_type) .map_err(|error| error.at_node(statement_node, source))?; } else { type_definition .inner() .check(&identifier_type) .map_err(|error| error.at_node(identifier_node, source))?; } } AssignmentOperator::MinusEqual => todo!(), } } else { match operator { AssignmentOperator::Equal => {} AssignmentOperator::PlusEqual => { if let Type::List(item_type) = identifier_type { item_type .check(&statement_type) .map_err(|error| error.at_node(statement_node, source))?; } } AssignmentOperator::MinusEqual => todo!(), } } let variable_key = identifier.inner().clone(); let variable_type = if let Some(definition) = &type_definition { definition.inner().clone() } else { statement_type }; context.set(variable_key, Value::Option(None), Some(variable_type))?; Ok(Assignment { identifier, type_definition, operator, statement, }) } fn run(&self, source: &str, context: &Map) -> Result { let key = self.identifier.inner(); let value = self.statement.run(source, context)?; let new_value = match self.operator { AssignmentOperator::PlusEqual => { if let Some((mut previous_value, _)) = context.variables()?.get(key).cloned() { previous_value += value; previous_value } else { return Err(Error::VariableIdentifierNotFound(key.clone())); } } AssignmentOperator::MinusEqual => { if let Some((mut previous_value, _)) = context.variables()?.get(key).cloned() { previous_value -= value; previous_value } else { return Err(Error::VariableIdentifierNotFound(key.clone())); } } AssignmentOperator::Equal => value, }; if let Some(type_defintion) = &self.type_definition { context.set(key.clone(), new_value, Some(type_defintion.inner().clone()))?; } else { context.set(key.clone(), new_value, None)?; } Ok(Value::Option(None)) } fn expected_type(&self, _context: &Map) -> Result { Ok(Type::None) } } #[cfg(test)] mod tests { use crate::{evaluate, Error, List, Type, Value}; #[test] fn simple_assignment() { let test = evaluate("x = 1 x").unwrap(); assert_eq!(Value::Integer(1), test); } #[test] fn simple_assignment_with_type() { let test = evaluate("x = 1 x").unwrap(); assert_eq!(Value::Integer(1), test); } #[test] fn list_add_assign() { let test = evaluate( " x <[int]> = [] x += 1 x ", ) .unwrap(); assert_eq!(Value::List(List::with_items(vec![Value::Integer(1)])), test); } #[test] fn list_add_wrong_type() { let result = evaluate( " x <[str]> = [] x += 1 ", ); assert!(result.unwrap_err().is_type_check_error(&Error::TypeCheck { expected: Type::String, actual: Type::Integer })) } }