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nac3/nac3core/src/symbol_resolver.rs

175 lines
6.9 KiB
Rust

use std::cell::RefCell;
use std::collections::HashMap;
use crate::top_level::{DefinitionId, TopLevelContext, TopLevelDef};
use crate::typecheck::{
type_inferencer::PrimitiveStore,
typedef::{Type, Unifier},
};
use crate::{location::Location, typecheck::typedef::TypeEnum};
use itertools::{chain, izip};
use rustpython_parser::ast::Expr;
#[derive(Clone, PartialEq)]
pub enum SymbolValue {
I32(i32),
I64(i64),
Double(f64),
Bool(bool),
Tuple(Vec<SymbolValue>),
// we should think about how to implement bytes later...
// Bytes(&'a [u8]),
}
pub trait SymbolResolver {
// get type of type variable identifier or top-level function type
fn get_symbol_type(
&self,
unifier: &mut Unifier,
primitives: &PrimitiveStore,
str: &str,
) -> Option<Type>;
// get the top-level definition of identifiers
fn get_identifier_def(&self, str: &str) -> Option<DefinitionId>;
fn get_symbol_value(&self, str: &str) -> Option<SymbolValue>;
fn get_symbol_location(&self, str: &str) -> Option<Location>;
// handle function call etc.
}
// convert type annotation into type
pub fn parse_type_annotation<T>(
resolver: &dyn SymbolResolver,
top_level: &TopLevelContext,
unifier: &mut Unifier,
primitives: &PrimitiveStore,
expr: &Expr<T>,
) -> Result<Type, String> {
use rustpython_parser::ast::ExprKind::*;
match &expr.node {
Name { id, .. } => match id.as_str() {
"int32" => Ok(primitives.int32),
"int64" => Ok(primitives.int64),
"float" => Ok(primitives.float),
"bool" => Ok(primitives.bool),
"None" => Ok(primitives.none),
x => {
let obj_id = resolver.get_identifier_def(x);
if let Some(obj_id) = obj_id {
let defs = top_level.definitions.read();
let def = defs[obj_id.0].read();
if let TopLevelDef::Class { fields, methods, type_vars, .. } = &*def {
if !type_vars.is_empty() {
return Err(format!(
"Unexpected number of type parameters: expected {} but got 0",
type_vars.len()
));
}
let fields = RefCell::new(
chain(
fields.iter().map(|(k, v)| (k.clone(), *v)),
methods.iter().map(|(k, v, _)| (k.clone(), *v)),
)
.collect(),
);
Ok(unifier.add_ty(TypeEnum::TObj {
obj_id,
fields,
params: Default::default(),
}))
} else {
Err("Cannot use function name as type".into())
}
} else {
// it could be a type variable
let ty = resolver
.get_symbol_type(unifier, primitives, x)
.ok_or_else(|| "Cannot use function name as type".to_owned())?;
if let TypeEnum::TVar { .. } = &*unifier.get_ty(ty) {
Ok(ty)
} else {
Err(format!("Unknown type annotation {}", x))
}
}
}
},
Subscript { value, slice, .. } => {
if let Name { id, .. } = &value.node {
if id == "virtual" {
let ty =
parse_type_annotation(resolver, top_level, unifier, primitives, slice)?;
Ok(unifier.add_ty(TypeEnum::TVirtual { ty }))
} else {
let types = if let Tuple { elts, .. } = &slice.node {
elts.iter()
.map(|v| {
parse_type_annotation(resolver, top_level, unifier, primitives, v)
})
.collect::<Result<Vec<_>, _>>()?
} else {
vec![parse_type_annotation(
resolver, top_level, unifier, primitives, slice,
)?]
};
let obj_id = resolver
.get_identifier_def(id)
.ok_or_else(|| format!("Unknown type annotation {}", id))?;
let defs = top_level.definitions.read();
let def = defs[obj_id.0].read();
if let TopLevelDef::Class { fields, methods, type_vars, .. } = &*def {
if types.len() != type_vars.len() {
return Err(format!(
"Unexpected number of type parameters: expected {} but got {}",
type_vars.len(),
types.len()
));
}
let mut subst = HashMap::new();
for (var, ty) in izip!(type_vars.iter(), types.iter()) {
let id = if let TypeEnum::TVar { id, .. } = &*unifier.get_ty(*var) {
*id
} else {
unreachable!()
};
subst.insert(id, *ty);
}
let mut fields = fields
.iter()
.map(|(attr, ty)| {
let ty = unifier.subst(*ty, &subst).unwrap_or(*ty);
(attr.clone(), ty)
})
.collect::<HashMap<_, _>>();
fields.extend(methods.iter().map(|(attr, ty, _)| {
let ty = unifier.subst(*ty, &subst).unwrap_or(*ty);
(attr.clone(), ty)
}));
Ok(unifier.add_ty(TypeEnum::TObj {
obj_id,
fields: fields.into(),
params: subst.into(),
}))
} else {
Err("Cannot use function name as type".into())
}
}
} else {
Err("unsupported type expression".into())
}
}
_ => Err("unsupported type expression".into()),
}
}
impl dyn SymbolResolver + Send + Sync {
pub fn parse_type_annotation<T>(
&self,
top_level: &TopLevelContext,
unifier: &mut Unifier,
primitives: &PrimitiveStore,
expr: &Expr<T>,
) -> Result<Type, String> {
parse_type_annotation(self, top_level, unifier, primitives, expr)
}
}