85 lines
2.2 KiB
Rust
85 lines
2.2 KiB
Rust
use crate::{
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context::Context,
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error::{RuntimeError, ValidationError},
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};
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use super::{AbstractTree, Action, Statement, Type};
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#[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
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pub struct Block {
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statements: Vec<Statement>,
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}
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impl Block {
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pub fn new(statements: Vec<Statement>) -> Self {
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Self { statements }
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}
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}
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impl AbstractTree for Block {
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fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
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if let Some(statement) = self.statements.last() {
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statement.expected_type(_context)
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} else {
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Ok(Type::None)
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}
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}
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fn validate(&self, _context: &Context) -> Result<(), ValidationError> {
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for statement in &self.statements {
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statement.validate(_context)?;
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}
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Ok(())
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}
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fn run(self, _context: &Context) -> Result<Action, RuntimeError> {
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let mut previous = Action::None;
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for statement in self.statements {
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let action = statement.run(_context)?;
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previous = match action {
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Action::Return(value) => Action::Return(value),
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Action::None => Action::None,
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Action::Break => return Ok(action),
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};
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}
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Ok(previous)
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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 crate::{
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abstract_tree::{Expression, ValueNode},
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Value,
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};
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use super::*;
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#[test]
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fn run_returns_value_of_final_statement() {
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let block = Block::new(vec![
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Statement::Expression(Expression::Value(ValueNode::Integer(1))),
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Statement::Expression(Expression::Value(ValueNode::Integer(2))),
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Statement::Expression(Expression::Value(ValueNode::Integer(42))),
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]);
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assert_eq!(
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block.run(&Context::new()),
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Ok(Action::Return(Value::integer(42)))
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)
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}
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#[test]
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fn expected_type_returns_type_of_final_statement() {
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let block = Block::new(vec![
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Statement::Expression(Expression::Value(ValueNode::String("42".to_string()))),
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Statement::Expression(Expression::Value(ValueNode::Integer(42))),
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]);
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assert_eq!(block.expected_type(&Context::new()), Ok(Type::Integer))
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}
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}
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