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dust/dust-lang/src/abstract_tree/block.rs

102 lines
2.6 KiB
Rust

use crate::{
context::Context,
error::{RuntimeError, ValidationError},
};
use super::{AbstractNode, Action, Statement, Type};
#[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
pub struct Block {
statements: Vec<Statement>,
}
impl Block {
pub fn new(statements: Vec<Statement>) -> Self {
Self { statements }
}
pub fn first_statement(&self) -> &Statement {
self.statements.first().unwrap()
}
pub fn last_statement(&self) -> &Statement {
self.statements.last().unwrap()
}
}
impl AbstractNode for Block {
fn expected_type(&self, _context: &mut Context) -> Result<Type, ValidationError> {
if let Some(statement) = self.statements.last() {
statement.expected_type(_context)
} else {
Ok(Type::None)
}
}
fn validate(
&self,
_context: &mut Context,
_manage_memory: bool,
) -> Result<(), ValidationError> {
for statement in &self.statements {
statement.validate(_context, _manage_memory)?;
}
Ok(())
}
fn run(self, _context: &mut Context, _manage_memory: bool) -> Result<Action, RuntimeError> {
let mut previous = Action::None;
for statement in self.statements {
previous = statement.run(_context, _manage_memory)?;
}
Ok(previous)
}
}
#[cfg(test)]
mod tests {
use crate::{
abstract_tree::{Expression, ValueNode, WithPos},
Value,
};
use super::*;
#[test]
fn run_returns_value_of_final_statement() {
let block = Block::new(vec![
Statement::Expression(Expression::Value(
ValueNode::Integer(1).with_position((0, 0)),
)),
Statement::Expression(Expression::Value(
ValueNode::Integer(2).with_position((0, 0)),
)),
Statement::Expression(Expression::Value(
ValueNode::Integer(42).with_position((0, 0)),
)),
]);
assert_eq!(
block.run(&mut Context::new(), true).unwrap(),
Action::Return(Value::integer(42))
)
}
#[test]
fn expected_type_returns_type_of_final_statement() {
let block = Block::new(vec![
Statement::Expression(Expression::Value(
ValueNode::String("42".to_string()).with_position((0, 0)),
)),
Statement::Expression(Expression::Value(
ValueNode::Integer(42).with_position((0, 0)),
)),
]);
assert_eq!(block.expected_type(&mut Context::new()), Ok(Type::Integer))
}
}