diff options
Diffstat (limited to 'src/bidirectional.rs')
| -rw-r--r-- | src/bidirectional.rs | 38 |
1 files changed, 20 insertions, 18 deletions
diff --git a/src/bidirectional.rs b/src/bidirectional.rs index 4b34ab2..4e69372 100644 --- a/src/bidirectional.rs +++ b/src/bidirectional.rs @@ -26,7 +26,7 @@ impl Context { }, // Bt-Abs Expression::Abstraction { param, func } => match target { - Type::Function { from, to } => { + Type::Function(from, to) => { let mut context = self.clone(); context.insert_term(param, from.default()?); return context.check(*func, &to); @@ -65,14 +65,14 @@ impl Context { }, // Bt-App Expression::Application { func, arg } => match self.infer(*func)? { - Type::Function { from, to } => self.check(*arg, &*from).map(|x| *to), - _ => Err(format!("application abstraction is not a function type").into()) + Type::Function(from, to) => self.check(*arg, &*from).map(|x| *to), + _ => Err("application abstraction is not a function type".into()) }, // inference from an abstraction is always an error // we could try and infer the func without adding the parameter to scope: // but this is overwhelmingly likely to be an error, so just report it now. Expression::Abstraction { param, func } => - Err(format!("attempting to infer from an abstraction").into()), + Err("attempting to infer from an abstraction".into()), // idk Expression::Conditional { if_cond, if_then, if_else } => { self.check(*if_cond, &Type::Boolean)?; @@ -91,6 +91,12 @@ impl Context { /// "is" is a subtype of "of", i.e. "is" can be safely used in any context "of" is expected. pub fn subtype(&self, is: &Type, of: &Type) -> bool { match (is, of) { + (_, Type::Empty) => true, // top type: every type is a subtype of the empty type (empty as in structurally empty) + (Type::Error, _) => true, // bottom type: no type is a subtype of the error type + (Type::Natural, Type::Integer) => true, // obviously not, but let's pretend + (Type::List(is), Type::Slice(of)) | (Type::Array(is, _), Type::Slice(of)) | + (Type::List(is), Type::List(of)) | (Type::Slice(is), Type::Slice(of)) => self.subtype(is, of), + (Type::Array(is, is_size), Type::Array(of, of_size)) => self.subtype(is, of) && is_size == of_size, (Type::Tuple(is_data, is_fields), Type::Tuple(of_data, of_fields)) => { // length, order, and subtype if is_data.len() != of_data.len() || is_fields.len() != of_fields.len() { @@ -131,8 +137,7 @@ impl Context { } true }, - (Type::Function { from: is_from, to: is_to }, - Type::Function { from: of_from, to: of_to }) => { + (Type::Function(is_from, is_to), Type::Function(of_from, of_to)) => { self.subtype(of_from, is_from) && self.subtype(is_to, of_to) }, (is, Type::Interface(signatures, associated)) => { @@ -151,12 +156,8 @@ impl Context { } true }, - (Type::List(is), Type::Slice(of)) | (Type::Array(is, _), Type::Slice(of)) | - (Type::List(is), Type::List(of)) | (Type::Slice(is), Type::Slice(of)) => self.subtype(is, of), - (Type::Array(is, is_size), Type::Array(of, of_size)) => self.subtype(is, of) && is_size == of_size, - (Type::Natural, Type::Integer) => true, // obviously not, but let's pretend - (_, Type::Empty) => true, // top type: every type is a subtype of the empty type (empty as in structurally empty) - (Type::Error, _) => true, // bottom type: no type is a subtype of the error type + (is, Type::Generic(Some(data))) => data.contains(is), + (_, Type::Generic(None)) => true, (_, _) => is == of } } @@ -178,12 +179,13 @@ impl Type { data.iter().map(|(k, v)| (k.clone(), v.clone().deselfify(replacement))).collect()), Type::Tuple(data, idents) => Type::Tuple( data.iter().map(|x| x.clone().deselfify(replacement)).collect(), idents), - Type::Function { from, to } => Type::Function { - from: Box::new(from.deselfify(replacement)), - to: Box::new(to.deselfify(replacement)) - }, - Type::Interface(signatures, associated) => - Type::Interface(signatures, associated.map(|x| Box::new(x.deselfify(replacement)))), + Type::Function(from, to) => Type::Function( + Box::new(from.deselfify(replacement)), Box::new(to.deselfify(replacement))), + Type::Interface(signatures, associated) => Type::Interface(signatures, + associated.map(|x| Box::new(x.deselfify(replacement)))), + Type::Generic(Some(data)) => Type::Generic( + Some(data.iter().map(|x| x.clone().deselfify(replacement)).collect())), + Type::Generic(None) => Type::Generic(None), } } } |