You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
|
|
|
use super::node_type::*;
|
|
|
|
|
|
|
|
/// Try to infer types of variables
|
|
|
|
pub(super) fn infer(program: &mut Program) -> Result<(), String> {
|
|
|
|
// TODO: Fix aweful nesting
|
|
|
|
for func in &mut program.func {
|
|
|
|
if let Statement::Block(statements) = &mut func.body {
|
|
|
|
for statement in statements {
|
|
|
|
match statement {
|
|
|
|
Statement::Declare(var, expr) => {
|
|
|
|
if let None = &var.ty {
|
|
|
|
if let Some(e) = expr {
|
|
|
|
var.ty = infer_expression(&e);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
_ => {}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
Ok(())
|
|
|
|
}
|
|
|
|
|
|
|
|
fn infer_expression(expr: &Expression) -> Option<Type> {
|
|
|
|
match expr {
|
|
|
|
Expression::Int(_) => Some(Type::Int),
|
|
|
|
Expression::Bool(_) => Some(Type::Bool),
|
|
|
|
Expression::Str(_) => Some(Type::Str),
|
|
|
|
Expression::Array(els) => infer_array(els),
|
|
|
|
_ => None,
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
fn infer_array(elements: &Vec<Expression>) -> Option<Type> {
|
|
|
|
let types: Vec<Option<Type>> = elements.iter().map(|el| infer_expression(el)).collect();
|
|
|
|
|
|
|
|
// TODO: This approach only relies on the first element.
|
|
|
|
// It will not catch that types are possibly inconsistent.
|
|
|
|
match types.first().and_then(|ty| ty.to_owned()) {
|
|
|
|
Some(ty) => Some(Type::Array(Box::new(ty))),
|
|
|
|
None => None,
|
|
|
|
}
|
|
|
|
}
|