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