mirror of
https://github.com/erg-lang/erg.git
synced 2025-09-29 12:24:45 +00:00
1194 lines
50 KiB
Rust
1194 lines
50 KiB
Rust
//! provides type variable related operations
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use std::mem;
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use std::option::Option;
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use erg_common::error::Location;
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use erg_common::set::Set;
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use erg_common::traits::Stream;
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use erg_common::Str;
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use erg_common::{assume_unreachable, fn_name, set};
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use erg_type::constructors::*;
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use erg_type::free::{Constraint, Cyclicity, FreeKind, HasLevel};
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use erg_type::typaram::TyParam;
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use erg_type::value::ValueObj;
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use erg_type::{HasType, Predicate, TyBound, Type};
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use crate::context::{Context, Variance};
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use crate::error::{TyCheckError, TyCheckResult};
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use crate::hir;
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use Predicate as Pred;
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use Type::*;
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use ValueObj::{Inf, NegInf};
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impl Context {
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pub const TOP_LEVEL: usize = 1;
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// HACK: see doc/compiler/inference.md for details
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pub const GENERIC_LEVEL: usize = usize::MAX;
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/// 型を非依存化する
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fn _independentise<'a>(_t: Type, _ts: &[Type]) -> Type {
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todo!()
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}
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fn generalize_tp(
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&self,
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free: TyParam,
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bounds: &mut Set<TyBound>,
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lazy_inits: &mut Set<Str>,
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) -> TyParam {
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match free {
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TyParam::Type(t) => TyParam::t(self.generalize_t_inner(*t, bounds, lazy_inits)),
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TyParam::FreeVar(v) if v.is_linked() => {
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if let FreeKind::Linked(tp) = &mut *v.borrow_mut() {
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*tp = self.generalize_tp(tp.clone(), bounds, lazy_inits);
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} else {
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assume_unreachable!()
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}
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TyParam::FreeVar(v)
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}
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// TODO: Polymorphic generalization
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TyParam::FreeVar(fv) if fv.level() > Some(self.level) => match &*fv.borrow() {
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FreeKind::Unbound { id, constraint, .. } => {
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let name = id.to_string();
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self.generalize_constraint(&name, constraint, bounds, lazy_inits);
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TyParam::mono_q(name)
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}
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FreeKind::NamedUnbound {
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name, constraint, ..
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} => {
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self.generalize_constraint(name, constraint, bounds, lazy_inits);
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TyParam::mono_q(name)
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}
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_ => assume_unreachable!(),
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},
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other if other.has_no_unbound_var() => other,
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other => todo!("{other}"),
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}
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}
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pub(crate) fn generalize_t(&self, free_type: Type) -> Type {
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let mut bounds = set! {};
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let mut lazy_inits = set! {};
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let maybe_unbound_t = self.generalize_t_inner(free_type, &mut bounds, &mut lazy_inits);
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// NOTE: ?T(<: TraitX) -> Intなどは単なるTraitX -> Intとなる
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if bounds.is_empty() {
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maybe_unbound_t
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} else {
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quant(maybe_unbound_t, bounds)
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}
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}
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/// see doc/LANG/compiler/inference.md#一般化 for details
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/// ```python
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/// generalize_t(?T) == 'T: Type
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/// generalize_t(?T(<: Nat) -> ?T) == |'T <: Nat| 'T -> 'T
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/// generalize_t(?T(<: Eq(?T(<: Eq(?T(<: ...)))) -> ?T) == |'T <: Eq('T)| 'T -> 'T
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/// generalize_t(?T(<: TraitX) -> Int) == TraitX -> Int // 戻り値に現れないなら量化しない
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/// ```
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fn generalize_t_inner(
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&self,
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free_type: Type,
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bounds: &mut Set<TyBound>,
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lazy_inits: &mut Set<Str>,
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) -> Type {
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match free_type {
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FreeVar(v) if v.is_linked() => {
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if let FreeKind::Linked(t) = &mut *v.borrow_mut() {
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*t = self.generalize_t_inner(t.clone(), bounds, lazy_inits);
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} else {
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assume_unreachable!()
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}
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Type::FreeVar(v)
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}
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// TODO: Polymorphic generalization
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FreeVar(fv) if fv.level().unwrap() > self.level => match &*fv.borrow() {
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FreeKind::Unbound { id, constraint, .. } => {
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let name = id.to_string();
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self.generalize_constraint(&name, constraint, bounds, lazy_inits);
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mono_q(name)
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}
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FreeKind::NamedUnbound {
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name, constraint, ..
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} => {
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self.generalize_constraint(name, constraint, bounds, lazy_inits);
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mono_q(name)
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}
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_ => assume_unreachable!(),
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},
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Subr(mut subr) => {
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subr.non_default_params.iter_mut().for_each(|nd_param| {
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*nd_param.typ_mut() =
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self.generalize_t_inner(mem::take(nd_param.typ_mut()), bounds, lazy_inits);
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});
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if let Some(var_args) = &mut subr.var_params {
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*var_args.typ_mut() =
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self.generalize_t_inner(mem::take(var_args.typ_mut()), bounds, lazy_inits);
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}
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subr.default_params.iter_mut().for_each(|d_param| {
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*d_param.typ_mut() =
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self.generalize_t_inner(mem::take(d_param.typ_mut()), bounds, lazy_inits);
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});
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let return_t = self.generalize_t_inner(*subr.return_t, bounds, lazy_inits);
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subr_t(
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subr.kind,
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subr.non_default_params,
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subr.var_params.map(|x| *x),
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subr.default_params,
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return_t,
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)
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}
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Callable { .. } => todo!(),
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Ref(t) => ref_(self.generalize_t_inner(*t, bounds, lazy_inits)),
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RefMut { before, after } => {
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let after = if let Some(after) = after {
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Some(self.generalize_t_inner(*after, bounds, lazy_inits))
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} else {
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None
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};
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ref_mut(self.generalize_t_inner(*before, bounds, lazy_inits), after)
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}
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Poly { name, mut params } => {
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let params = params
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.iter_mut()
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.map(|p| self.generalize_tp(mem::take(p), bounds, lazy_inits))
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.collect::<Vec<_>>();
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poly(name, params)
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}
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// REVIEW: その他何でもそのまま通していいのか?
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other => other,
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}
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}
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fn generalize_constraint<S: Into<Str>>(
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&self,
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name: S,
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constraint: &Constraint,
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bounds: &mut Set<TyBound>,
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lazy_inits: &mut Set<Str>,
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) {
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let name = name.into();
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// Quantify types with type boundaries only at the top level
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// トップレベルでのみ、型境界付きで量化する
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if !lazy_inits.contains(&name[..]) {
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lazy_inits.insert(name.clone());
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match constraint {
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Constraint::Sandwiched { sub, sup, .. } => {
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let sub = self.generalize_t_inner(sub.clone(), bounds, lazy_inits);
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let sup = self.generalize_t_inner(sup.clone(), bounds, lazy_inits);
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// let bs = sub_bs.concat(sup_bs);
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bounds.insert(TyBound::sandwiched(sub, mono_q(name.clone()), sup));
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}
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Constraint::TypeOf(t) => {
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let t = self.generalize_t_inner(t.clone(), bounds, lazy_inits);
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bounds.insert(TyBound::instance(Str::rc(&name[..]), t));
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}
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Constraint::Uninited => unreachable!(),
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}
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}
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}
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fn deref_tp(&self, tp: TyParam) -> TyCheckResult<TyParam> {
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match tp {
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TyParam::FreeVar(fv) if fv.is_linked() => {
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let inner = fv.unwrap_linked();
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self.deref_tp(inner)
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}
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TyParam::FreeVar(_fv) if self.level == 0 => {
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Err(TyCheckError::dummy_infer_error(fn_name!(), line!()))
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}
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TyParam::Type(t) => Ok(TyParam::t(self.deref_tyvar(*t)?)),
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TyParam::App { name, mut args } => {
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for param in args.iter_mut() {
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*param = self.deref_tp(mem::take(param))?;
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}
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Ok(TyParam::App { name, args })
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}
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TyParam::BinOp { .. } => todo!(),
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TyParam::UnaryOp { .. } => todo!(),
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TyParam::Array(_) | TyParam::Tuple(_) => todo!(),
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TyParam::MonoProj { .. }
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| TyParam::MonoQVar(_)
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| TyParam::PolyQVar { .. }
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| TyParam::Failure
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if self.level == 0 =>
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{
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Err(TyCheckError::dummy_infer_error(fn_name!(), line!()))
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}
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t => Ok(t),
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}
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}
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fn deref_constraint(&self, constraint: Constraint) -> TyCheckResult<Constraint> {
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match constraint {
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Constraint::Sandwiched {
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sub,
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sup,
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cyclicity: cyclic,
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} => {
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if cyclic.is_cyclic() {
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return Err(TyCheckError::dummy_infer_error(fn_name!(), line!()));
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}
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Ok(Constraint::new_sandwiched(
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self.deref_tyvar(sub)?,
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self.deref_tyvar(sup)?,
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cyclic,
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))
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}
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Constraint::TypeOf(t) => Ok(Constraint::new_type_of(self.deref_tyvar(t)?)),
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_ => unreachable!(),
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}
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}
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/// e.g.
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/// ```python
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/// deref_tyvar(?T(:> Never, <: Int)[n]): ?T => Int (if self.level <= n)
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/// deref_tyvar((Int)): (Int) => Int
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/// ```
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pub(crate) fn deref_tyvar(&self, t: Type) -> TyCheckResult<Type> {
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match t {
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// ?T(:> Nat, <: Int)[n] => Nat (self.level <= n)
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// ?T(:> Nat, <: Sub ?U(:> {1}))[n] => Nat
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// ?T(:> Never, <: Nat)[n] => Nat
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Type::FreeVar(fv) if fv.constraint_is_sandwiched() => {
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let constraint = fv.crack_constraint();
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let (sub_t, super_t) = constraint.get_sub_sup().unwrap();
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if self.rec_same_type_of(sub_t, super_t) {
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self.unify(sub_t, super_t, None, None)?;
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let t = if sub_t == &Never {
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super_t.clone()
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} else {
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sub_t.clone()
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};
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drop(constraint);
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fv.link(&t);
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self.deref_tyvar(Type::FreeVar(fv))
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} else if self.level <= fv.level().unwrap() {
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let new_t = if sub_t == &Never {
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super_t.clone()
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} else {
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sub_t.clone()
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};
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drop(constraint);
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fv.link(&new_t);
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self.deref_tyvar(Type::FreeVar(fv))
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} else {
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drop(constraint);
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Ok(Type::FreeVar(fv))
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}
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}
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Type::FreeVar(fv) if fv.is_unbound() => {
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if self.level == 0 {
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match &*fv.crack_constraint() {
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Constraint::TypeOf(_) => {
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Err(TyCheckError::dummy_infer_error(fn_name!(), line!()))
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}
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_ => unreachable!(),
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}
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} else {
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let new_constraint = fv.crack_constraint().clone();
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let new_constraint = self.deref_constraint(new_constraint)?;
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fv.update_constraint(new_constraint);
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Ok(Type::FreeVar(fv))
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}
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}
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Type::FreeVar(fv) if fv.is_linked() => {
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let t = fv.unwrap_linked();
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self.deref_tyvar(t)
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}
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Type::Poly { name, mut params } => {
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for param in params.iter_mut() {
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*param = self.deref_tp(mem::take(param))?;
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}
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let t = Type::Poly { name, params };
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self.resolve_trait(t)
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}
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Type::Subr(mut subr) => {
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for param in subr.non_default_params.iter_mut() {
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*param.typ_mut() = self.deref_tyvar(mem::take(param.typ_mut()))?;
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}
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if let Some(var_args) = &mut subr.var_params {
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*var_args.typ_mut() = self.deref_tyvar(mem::take(var_args.typ_mut()))?;
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}
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for d_param in subr.default_params.iter_mut() {
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*d_param.typ_mut() = self.deref_tyvar(mem::take(d_param.typ_mut()))?;
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}
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subr.return_t = Box::new(self.deref_tyvar(mem::take(&mut subr.return_t))?);
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Ok(Type::Subr(subr))
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}
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Type::Ref(t) => {
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let t = self.deref_tyvar(*t)?;
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Ok(ref_(t))
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}
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Type::RefMut { before, after } => {
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let before = self.deref_tyvar(*before)?;
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let after = if let Some(after) = after {
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Some(self.deref_tyvar(*after)?)
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} else {
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None
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};
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Ok(ref_mut(before, after))
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}
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Type::Callable { .. } => todo!(),
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Type::Record(mut rec) => {
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for (_, field) in rec.iter_mut() {
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*field = self.deref_tyvar(mem::take(field))?;
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}
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Ok(Type::Record(rec))
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}
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Type::Refinement(refine) => {
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let t = self.deref_tyvar(*refine.t)?;
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// TODO: deref_predicate
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Ok(refinement(refine.var, t, refine.preds))
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}
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t => Ok(t),
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}
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}
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pub(crate) fn deref_toplevel(&mut self, mut hir: hir::HIR) -> TyCheckResult<hir::HIR> {
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self.level = 0;
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for chunk in hir.module.iter_mut() {
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self.deref_expr_t(chunk).map_err(|e| e)?;
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}
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Ok(hir)
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}
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fn deref_expr_t(&self, expr: &mut hir::Expr) -> TyCheckResult<()> {
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match expr {
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hir::Expr::Lit(_) => Ok(()),
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hir::Expr::Accessor(acc) => {
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let t = acc.ref_mut_t();
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*t = self.deref_tyvar(mem::take(t))?;
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match acc {
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hir::Accessor::Attr(attr) => {
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self.deref_expr_t(&mut attr.obj)?;
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}
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hir::Accessor::TupleAttr(attr) => {
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self.deref_expr_t(&mut attr.obj)?;
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}
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hir::Accessor::Subscr(subscr) => {
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self.deref_expr_t(&mut subscr.obj)?;
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self.deref_expr_t(&mut subscr.index)?;
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}
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hir::Accessor::Local(_) | hir::Accessor::Public(_) => {}
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}
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Ok(())
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}
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hir::Expr::Array(array) => match array {
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hir::Array::Normal(arr) => {
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arr.t = self.deref_tyvar(mem::take(&mut arr.t))?;
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for elem in arr.elems.pos_args.iter_mut() {
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self.deref_expr_t(&mut elem.expr)?;
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}
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Ok(())
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}
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_ => todo!(),
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},
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hir::Expr::Tuple(tuple) => match tuple {
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hir::Tuple::Normal(tup) => {
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for elem in tup.elems.pos_args.iter_mut() {
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self.deref_expr_t(&mut elem.expr)?;
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}
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Ok(())
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}
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},
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hir::Expr::Dict(_dict) => {
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todo!()
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}
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hir::Expr::Record(record) => {
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for attr in record.attrs.iter_mut() {
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match &mut attr.sig {
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hir::Signature::Var(var) => {
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var.t = self.deref_tyvar(mem::take(&mut var.t))?;
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}
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hir::Signature::Subr(subr) => {
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subr.t = self.deref_tyvar(mem::take(&mut subr.t))?;
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}
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}
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for chunk in attr.body.block.iter_mut() {
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self.deref_expr_t(chunk)?;
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}
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}
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Ok(())
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}
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hir::Expr::BinOp(binop) => {
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let t = binop.signature_mut_t().unwrap();
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*t = self.deref_tyvar(mem::take(t))?;
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self.deref_expr_t(&mut binop.lhs)?;
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self.deref_expr_t(&mut binop.rhs)?;
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Ok(())
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}
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hir::Expr::UnaryOp(unaryop) => {
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let t = unaryop.signature_mut_t().unwrap();
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*t = self.deref_tyvar(mem::take(t))?;
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self.deref_expr_t(&mut unaryop.expr)?;
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Ok(())
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}
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hir::Expr::Call(call) => {
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let t = call.signature_mut_t().unwrap();
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*t = self.deref_tyvar(mem::take(t))?;
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for arg in call.args.pos_args.iter_mut() {
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self.deref_expr_t(&mut arg.expr)?;
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}
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for arg in call.args.kw_args.iter_mut() {
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self.deref_expr_t(&mut arg.expr)?;
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}
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Ok(())
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}
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hir::Expr::Decl(decl) => {
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decl.t = self.deref_tyvar(mem::take(&mut decl.t))?;
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Ok(())
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}
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hir::Expr::Def(def) => {
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match &mut def.sig {
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hir::Signature::Var(var) => {
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var.t = self.deref_tyvar(mem::take(&mut var.t))?;
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}
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hir::Signature::Subr(subr) => {
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subr.t = self.deref_tyvar(mem::take(&mut subr.t))?;
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}
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}
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for chunk in def.body.block.iter_mut() {
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self.deref_expr_t(chunk)?;
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}
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Ok(())
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}
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hir::Expr::Lambda(lambda) => {
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lambda.t = self.deref_tyvar(mem::take(&mut lambda.t))?;
|
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for chunk in lambda.body.iter_mut() {
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self.deref_expr_t(chunk)?;
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}
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Ok(())
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}
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hir::Expr::ClassDef(type_def) => {
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for def in type_def.public_methods.iter_mut() {
|
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match &mut def.sig {
|
|
hir::Signature::Var(var) => {
|
|
var.t = self.deref_tyvar(mem::take(&mut var.t))?;
|
|
}
|
|
hir::Signature::Subr(subr) => {
|
|
subr.t = self.deref_tyvar(mem::take(&mut subr.t))?;
|
|
}
|
|
}
|
|
for chunk in def.body.block.iter_mut() {
|
|
self.deref_expr_t(chunk)?;
|
|
}
|
|
}
|
|
Ok(())
|
|
}
|
|
hir::Expr::AttrDef(attr_def) => {
|
|
// REVIEW: attr_def.attr is not dereferenced
|
|
for chunk in attr_def.block.iter_mut() {
|
|
self.deref_expr_t(chunk)?;
|
|
}
|
|
Ok(())
|
|
}
|
|
}
|
|
}
|
|
|
|
fn _occur(&self, _t: Type) -> TyCheckResult<Type> {
|
|
todo!()
|
|
}
|
|
|
|
/// allow_divergence = trueにすると、Num型変数と±Infの単一化を許す
|
|
pub(crate) fn unify_tp(
|
|
&self,
|
|
lhs: &TyParam,
|
|
rhs: &TyParam,
|
|
lhs_variance: Option<&Vec<Variance>>,
|
|
allow_divergence: bool,
|
|
) -> TyCheckResult<()> {
|
|
if lhs.has_no_unbound_var() && rhs.has_no_unbound_var() && lhs == rhs {
|
|
return Ok(());
|
|
}
|
|
match (lhs, rhs) {
|
|
(TyParam::Type(l), TyParam::Type(r)) => self.unify(l, r, None, None),
|
|
(ltp @ TyParam::FreeVar(lfv), rtp @ TyParam::FreeVar(rfv))
|
|
if lfv.is_unbound() && rfv.is_unbound() =>
|
|
{
|
|
if lfv.level().unwrap() > rfv.level().unwrap() {
|
|
lfv.link(rtp);
|
|
} else {
|
|
rfv.link(ltp);
|
|
}
|
|
Ok(())
|
|
}
|
|
(TyParam::FreeVar(fv), tp) | (tp, TyParam::FreeVar(fv)) => {
|
|
match &*fv.borrow() {
|
|
FreeKind::Linked(l) | FreeKind::UndoableLinked { t: l, .. } => {
|
|
return self.unify_tp(l, tp, lhs_variance, allow_divergence);
|
|
}
|
|
FreeKind::Unbound { .. } | FreeKind::NamedUnbound { .. } => {}
|
|
} // &fv is dropped
|
|
let fv_t = fv
|
|
.borrow()
|
|
.constraint()
|
|
.unwrap()
|
|
.get_type()
|
|
.unwrap()
|
|
.clone(); // fvを参照しないよいにcloneする(あとでborrow_mutするため)
|
|
let tp_t = self.get_tp_t(tp)?;
|
|
if self.rec_supertype_of(&fv_t, &tp_t) {
|
|
// 外部未連携型変数の場合、linkしないで制約を弱めるだけにする(see compiler/inference.md)
|
|
if fv.level() < Some(self.level) {
|
|
let new_constraint = Constraint::new_subtype_of(tp_t, Cyclicity::Not);
|
|
if self.is_sub_constraint_of(
|
|
fv.borrow().constraint().unwrap(),
|
|
&new_constraint,
|
|
) || fv.borrow().constraint().unwrap().get_type() == Some(&Type)
|
|
{
|
|
fv.update_constraint(new_constraint);
|
|
}
|
|
} else {
|
|
fv.link(tp);
|
|
}
|
|
Ok(())
|
|
} else if allow_divergence
|
|
&& (self.eq_tp(tp, &TyParam::value(Inf))
|
|
|| self.eq_tp(tp, &TyParam::value(NegInf)))
|
|
&& self.rec_subtype_of(&fv_t, &mono("Num"))
|
|
{
|
|
fv.link(tp);
|
|
Ok(())
|
|
} else {
|
|
Err(TyCheckError::unreachable(fn_name!(), line!()))
|
|
}
|
|
}
|
|
(TyParam::UnaryOp { op: lop, val: lval }, TyParam::UnaryOp { op: rop, val: rval })
|
|
if lop == rop =>
|
|
{
|
|
self.unify_tp(lval, rval, lhs_variance, allow_divergence)
|
|
}
|
|
(
|
|
TyParam::BinOp { op: lop, lhs, rhs },
|
|
TyParam::BinOp {
|
|
op: rop,
|
|
lhs: lhs2,
|
|
rhs: rhs2,
|
|
},
|
|
) if lop == rop => {
|
|
self.unify_tp(lhs, lhs2, lhs_variance, allow_divergence)?;
|
|
self.unify_tp(rhs, rhs2, lhs_variance, allow_divergence)
|
|
}
|
|
(l, r) => panic!("type-parameter unification failed:\nl:{l}\nr: {r}"),
|
|
}
|
|
}
|
|
|
|
fn reunify_tp(&self, before: &TyParam, after: &TyParam) -> TyCheckResult<()> {
|
|
match (before, after) {
|
|
(TyParam::Value(ValueObj::Mut(l)), TyParam::Value(ValueObj::Mut(r))) => {
|
|
*l.borrow_mut() = r.borrow().clone();
|
|
Ok(())
|
|
}
|
|
(TyParam::Value(ValueObj::Mut(l)), TyParam::Value(r)) => {
|
|
*l.borrow_mut() = r.clone();
|
|
Ok(())
|
|
}
|
|
(TyParam::Type(l), TyParam::Type(r)) => self.reunify(l, r, None, None),
|
|
(TyParam::UnaryOp { op: lop, val: lval }, TyParam::UnaryOp { op: rop, val: rval })
|
|
if lop == rop =>
|
|
{
|
|
self.reunify_tp(lval, rval)
|
|
}
|
|
(
|
|
TyParam::BinOp { op: lop, lhs, rhs },
|
|
TyParam::BinOp {
|
|
op: rop,
|
|
lhs: lhs2,
|
|
rhs: rhs2,
|
|
},
|
|
) if lop == rop => {
|
|
self.reunify_tp(lhs, lhs2)?;
|
|
self.reunify_tp(rhs, rhs2)
|
|
}
|
|
(l, r) if self.eq_tp(l, r) => Ok(()),
|
|
(l, r) => panic!("type-parameter re-unification failed:\nl: {l}\nr: {r}"),
|
|
}
|
|
}
|
|
|
|
/// predは正規化されているとする
|
|
fn unify_pred(&self, l_pred: &Predicate, r_pred: &Predicate) -> TyCheckResult<()> {
|
|
match (l_pred, r_pred) {
|
|
(Pred::Value(_), Pred::Value(_)) | (Pred::Const(_), Pred::Const(_)) => Ok(()),
|
|
(Pred::Equal { rhs, .. }, Pred::Equal { rhs: rhs2, .. })
|
|
| (Pred::GreaterEqual { rhs, .. }, Pred::GreaterEqual { rhs: rhs2, .. })
|
|
| (Pred::LessEqual { rhs, .. }, Pred::LessEqual { rhs: rhs2, .. })
|
|
| (Pred::NotEqual { rhs, .. }, Pred::NotEqual { rhs: rhs2, .. }) => {
|
|
self.unify_tp(rhs, rhs2, None, false)
|
|
}
|
|
(Pred::And(l1, r1), Pred::And(l2, r2))
|
|
| (Pred::Or(l1, r1), Pred::Or(l2, r2))
|
|
| (Pred::Not(l1, r1), Pred::Not(l2, r2)) => {
|
|
match (self.unify_pred(l1, l2), self.unify_pred(r1, r2)) {
|
|
(Ok(()), Ok(())) => Ok(()),
|
|
(Ok(()), Err(e)) | (Err(e), Ok(())) | (Err(e), Err(_)) => Err(e),
|
|
}
|
|
}
|
|
// unify({I >= 0}, {I >= ?M and I <= ?N}): ?M => 0, ?N => Inf
|
|
(Pred::GreaterEqual { rhs, .. }, Pred::And(l, r))
|
|
| (Predicate::And(l, r), Pred::GreaterEqual { rhs, .. }) => {
|
|
match (l.as_ref(), r.as_ref()) {
|
|
(
|
|
Pred::GreaterEqual { rhs: ge_rhs, .. },
|
|
Pred::LessEqual { rhs: le_rhs, .. },
|
|
)
|
|
| (
|
|
Pred::LessEqual { rhs: le_rhs, .. },
|
|
Pred::GreaterEqual { rhs: ge_rhs, .. },
|
|
) => {
|
|
self.unify_tp(rhs, ge_rhs, None, false)?;
|
|
self.unify_tp(le_rhs, &TyParam::value(Inf), None, true)
|
|
}
|
|
_ => Err(TyCheckError::pred_unification_error(
|
|
line!() as usize,
|
|
l_pred,
|
|
r_pred,
|
|
self.caused_by(),
|
|
)),
|
|
}
|
|
}
|
|
(Pred::LessEqual { rhs, .. }, Pred::And(l, r))
|
|
| (Pred::And(l, r), Pred::LessEqual { rhs, .. }) => match (l.as_ref(), r.as_ref()) {
|
|
(Pred::GreaterEqual { rhs: ge_rhs, .. }, Pred::LessEqual { rhs: le_rhs, .. })
|
|
| (Pred::LessEqual { rhs: le_rhs, .. }, Pred::GreaterEqual { rhs: ge_rhs, .. }) => {
|
|
self.unify_tp(rhs, le_rhs, None, false)?;
|
|
self.unify_tp(ge_rhs, &TyParam::value(NegInf), None, true)
|
|
}
|
|
_ => Err(TyCheckError::pred_unification_error(
|
|
line!() as usize,
|
|
l_pred,
|
|
r_pred,
|
|
self.caused_by(),
|
|
)),
|
|
},
|
|
(Pred::Equal { rhs, .. }, Pred::And(l, r))
|
|
| (Pred::And(l, r), Pred::Equal { rhs, .. }) => match (l.as_ref(), r.as_ref()) {
|
|
(Pred::GreaterEqual { rhs: ge_rhs, .. }, Pred::LessEqual { rhs: le_rhs, .. })
|
|
| (Pred::LessEqual { rhs: le_rhs, .. }, Pred::GreaterEqual { rhs: ge_rhs, .. }) => {
|
|
self.unify_tp(rhs, le_rhs, None, false)?;
|
|
self.unify_tp(rhs, ge_rhs, None, false)
|
|
}
|
|
_ => Err(TyCheckError::pred_unification_error(
|
|
line!() as usize,
|
|
l_pred,
|
|
r_pred,
|
|
self.caused_by(),
|
|
)),
|
|
},
|
|
_ => Err(TyCheckError::pred_unification_error(
|
|
line!() as usize,
|
|
l_pred,
|
|
r_pred,
|
|
self.caused_by(),
|
|
)),
|
|
}
|
|
}
|
|
|
|
/// By default, all type variables are instances of Class ('T: Nominal)
|
|
/// So `unify(?T, Int); unify(?T, Bool)` will causes an error
|
|
/// To bypass the constraint, you need to specify `'T: Structural` in the type bounds
|
|
pub(crate) fn unify(
|
|
&self,
|
|
lhs_t: &Type,
|
|
rhs_t: &Type,
|
|
lhs_loc: Option<Location>,
|
|
rhs_loc: Option<Location>,
|
|
) -> TyCheckResult<()> {
|
|
if lhs_t.has_no_unbound_var()
|
|
&& rhs_t.has_no_unbound_var()
|
|
&& self.rec_supertype_of(lhs_t, rhs_t)
|
|
{
|
|
return Ok(());
|
|
}
|
|
match (lhs_t, rhs_t) {
|
|
// unify(?T[2], ?U[3]): ?U[3] => ?T[2]
|
|
// bind the higher level var to lower one
|
|
(lt @ Type::FreeVar(lfv), rt @ Type::FreeVar(rfv))
|
|
if lfv.is_unbound() && rfv.is_unbound() =>
|
|
{
|
|
if lfv.constraint_is_typeof() && !rfv.constraint_is_typeof() {
|
|
lfv.update_constraint(rfv.crack_constraint().clone());
|
|
} else if rfv.constraint_is_typeof() && !lfv.constraint_is_typeof() {
|
|
rfv.update_constraint(lfv.crack_constraint().clone());
|
|
}
|
|
if lfv.level().unwrap() > rfv.level().unwrap() {
|
|
lfv.link(rt);
|
|
} else {
|
|
rfv.link(lt);
|
|
}
|
|
Ok(())
|
|
}
|
|
// unify(?L(<: Add(?R, ?O)), Nat): (?R => Nat, ?O => Nat, ?L => Nat)
|
|
// unify(?A(<: Mutate), [?T; 0]): (?A => [?T; 0])
|
|
(Type::FreeVar(fv), t) | (t, Type::FreeVar(fv)) => {
|
|
match &mut *fv.borrow_mut() {
|
|
FreeKind::Linked(l) | FreeKind::UndoableLinked { t: l, .. } => {
|
|
return self.unify(l, t, lhs_loc, rhs_loc);
|
|
}
|
|
FreeKind::Unbound {
|
|
lev, constraint, ..
|
|
}
|
|
| FreeKind::NamedUnbound {
|
|
lev, constraint, ..
|
|
} => {
|
|
t.update_level(*lev);
|
|
// TODO: constraint.type_of()
|
|
if let Some(sup) = constraint.get_super_mut() {
|
|
// 下のような場合は制約を弱化する
|
|
// unify(?T(<: Nat), Int): (?T(<: Int))
|
|
if self.rec_subtype_of(sup, t) {
|
|
*sup = t.clone();
|
|
} else {
|
|
self.sub_unify(t, sup, rhs_loc, lhs_loc, None)?;
|
|
}
|
|
}
|
|
}
|
|
} // &fv is dropped
|
|
let new_constraint = Constraint::new_subtype_of(t.clone(), fv.cyclicity());
|
|
// 外部未連携型変数の場合、linkしないで制約を弱めるだけにする(see compiler/inference.md)
|
|
// fv == ?T(: Type)の場合は?T(<: U)にする
|
|
if fv.level() < Some(self.level) {
|
|
if self.is_sub_constraint_of(fv.borrow().constraint().unwrap(), &new_constraint)
|
|
|| fv.borrow().constraint().unwrap().get_type() == Some(&Type)
|
|
{
|
|
fv.update_constraint(new_constraint);
|
|
}
|
|
} else {
|
|
fv.link(t);
|
|
}
|
|
Ok(())
|
|
}
|
|
(Type::Refinement(l), Type::Refinement(r)) => {
|
|
if !self.structural_supertype_of(&l.t, &r.t)
|
|
&& !self.structural_supertype_of(&r.t, &l.t)
|
|
{
|
|
return Err(TyCheckError::unification_error(
|
|
line!() as usize,
|
|
lhs_t,
|
|
rhs_t,
|
|
lhs_loc,
|
|
rhs_loc,
|
|
self.caused_by(),
|
|
));
|
|
}
|
|
// FIXME: 正規化する
|
|
for l_pred in l.preds.iter() {
|
|
for r_pred in r.preds.iter() {
|
|
self.unify_pred(l_pred, r_pred)?;
|
|
}
|
|
}
|
|
Ok(())
|
|
}
|
|
(Type::Refinement(_), r) => {
|
|
let rhs_t = self.into_refinement(r.clone());
|
|
self.unify(lhs_t, &Type::Refinement(rhs_t), lhs_loc, rhs_loc)
|
|
}
|
|
(l, Type::Refinement(_)) => {
|
|
let lhs_t = self.into_refinement(l.clone());
|
|
self.unify(&Type::Refinement(lhs_t), rhs_t, lhs_loc, rhs_loc)
|
|
}
|
|
(Type::Subr(ls), Type::Subr(rs)) if ls.kind == rs.kind => {
|
|
for (l, r) in ls
|
|
.non_default_params
|
|
.iter()
|
|
.zip(rs.non_default_params.iter())
|
|
{
|
|
self.unify(l.typ(), r.typ(), lhs_loc, rhs_loc)?;
|
|
}
|
|
for (l, r) in ls.var_params.as_ref().zip(rs.var_params.as_ref()) {
|
|
self.unify(l.typ(), r.typ(), lhs_loc, rhs_loc)?;
|
|
}
|
|
for lpt in ls.default_params.iter() {
|
|
if let Some(rpt) = rs
|
|
.default_params
|
|
.iter()
|
|
.find(|rpt| rpt.name() == lpt.name())
|
|
{
|
|
self.unify(lpt.typ(), rpt.typ(), lhs_loc, rhs_loc)?;
|
|
} else {
|
|
todo!()
|
|
}
|
|
}
|
|
self.unify(&ls.return_t, &rs.return_t, lhs_loc, rhs_loc)
|
|
}
|
|
(Type::Ref(l), Type::Ref(r)) => self.unify(l, r, lhs_loc, rhs_loc),
|
|
(
|
|
Type::RefMut {
|
|
before: lbefore,
|
|
after: lafter,
|
|
},
|
|
Type::RefMut {
|
|
before: rbefore,
|
|
after: rafter,
|
|
},
|
|
) => {
|
|
self.unify(lbefore, rbefore, lhs_loc, rhs_loc)?;
|
|
match (lafter, rafter) {
|
|
(Some(lafter), Some(rafter)) => {
|
|
self.unify(lafter, rafter, lhs_loc, rhs_loc)?;
|
|
}
|
|
(None, None) => {}
|
|
_ => todo!(),
|
|
}
|
|
Ok(())
|
|
}
|
|
(Type::Ref(l), r) => self.unify(l, r, lhs_loc, rhs_loc),
|
|
// REVIEW:
|
|
(Type::RefMut { before, .. }, r) => self.unify(before, r, lhs_loc, rhs_loc),
|
|
(l, Type::Ref(r)) => self.unify(l, r, lhs_loc, rhs_loc),
|
|
(l, Type::RefMut { before, .. }) => self.unify(l, before, lhs_loc, rhs_loc),
|
|
(
|
|
Type::Poly {
|
|
name: ln,
|
|
params: lps,
|
|
},
|
|
Type::Poly {
|
|
name: rn,
|
|
params: rps,
|
|
},
|
|
) => {
|
|
if ln != rn {
|
|
return Err(TyCheckError::unification_error(
|
|
line!() as usize,
|
|
lhs_t,
|
|
rhs_t,
|
|
lhs_loc,
|
|
rhs_loc,
|
|
self.caused_by(),
|
|
));
|
|
}
|
|
for (l, r) in lps.iter().zip(rps.iter()) {
|
|
self.unify_tp(l, r, None, false)?;
|
|
}
|
|
Ok(())
|
|
}
|
|
(Type::Poly { name: _, params: _ }, _r) => {
|
|
todo!()
|
|
}
|
|
(l, r) => Err(TyCheckError::unification_error(
|
|
line!() as usize,
|
|
l,
|
|
r,
|
|
lhs_loc,
|
|
rhs_loc,
|
|
self.caused_by(),
|
|
)),
|
|
}
|
|
}
|
|
|
|
/// T: Array(Int, !0), U: Array(Int, !1)
|
|
/// reunify(T, U):
|
|
/// T: Array(Int, !1), U: Array(Int, !1)
|
|
pub(crate) fn reunify(
|
|
&self,
|
|
before_t: &Type,
|
|
after_t: &Type,
|
|
bef_loc: Option<Location>,
|
|
aft_loc: Option<Location>,
|
|
) -> TyCheckResult<()> {
|
|
match (before_t, after_t) {
|
|
(Type::FreeVar(fv), r) if fv.is_linked() => {
|
|
self.reunify(&fv.crack(), r, bef_loc, aft_loc)
|
|
}
|
|
(l, Type::FreeVar(fv)) if fv.is_linked() => {
|
|
self.reunify(l, &fv.crack(), bef_loc, aft_loc)
|
|
}
|
|
(Type::Ref(l), Type::Ref(r)) => self.reunify(l, r, bef_loc, aft_loc),
|
|
(
|
|
Type::RefMut {
|
|
before: lbefore,
|
|
after: lafter,
|
|
},
|
|
Type::RefMut {
|
|
before: rbefore,
|
|
after: rafter,
|
|
},
|
|
) => {
|
|
self.reunify(lbefore, rbefore, bef_loc, aft_loc)?;
|
|
match (lafter, rafter) {
|
|
(Some(lafter), Some(rafter)) => {
|
|
self.reunify(lafter, rafter, bef_loc, aft_loc)?;
|
|
}
|
|
(None, None) => {}
|
|
_ => todo!(),
|
|
}
|
|
Ok(())
|
|
}
|
|
(Type::Ref(l), r) => self.reunify(l, r, bef_loc, aft_loc),
|
|
// REVIEW:
|
|
(Type::RefMut { before, .. }, r) => self.reunify(before, r, bef_loc, aft_loc),
|
|
(l, Type::Ref(r)) => self.reunify(l, r, bef_loc, aft_loc),
|
|
(l, Type::RefMut { before, .. }) => self.reunify(l, before, bef_loc, aft_loc),
|
|
(
|
|
Type::Poly {
|
|
name: ln,
|
|
params: lps,
|
|
},
|
|
Type::Poly {
|
|
name: rn,
|
|
params: rps,
|
|
},
|
|
) => {
|
|
if ln != rn {
|
|
let before_t = poly(ln.clone(), lps.clone());
|
|
return Err(TyCheckError::re_unification_error(
|
|
line!() as usize,
|
|
&before_t,
|
|
after_t,
|
|
bef_loc,
|
|
aft_loc,
|
|
self.caused_by(),
|
|
));
|
|
}
|
|
for (l, r) in lps.iter().zip(rps.iter()) {
|
|
self.reunify_tp(l, r)?;
|
|
}
|
|
Ok(())
|
|
}
|
|
(l, r) if self.rec_same_type_of(l, r) => Ok(()),
|
|
(l, r) => Err(TyCheckError::re_unification_error(
|
|
line!() as usize,
|
|
l,
|
|
r,
|
|
bef_loc,
|
|
aft_loc,
|
|
self.caused_by(),
|
|
)),
|
|
}
|
|
}
|
|
|
|
/// Assuming that `sub` is a subtype of `sup`, fill in the type variable to satisfy the assumption
|
|
///
|
|
/// When comparing arguments and parameter, the left side (`sub`) is the argument (found) and the right side (`sup`) is the parameter (expected)
|
|
///
|
|
/// The parameter type must be a supertype of the argument type
|
|
/// ```python
|
|
/// sub_unify({I: Int | I == 0}, ?T(<: Ord)): (/* OK */)
|
|
/// sub_unify(Int, ?T(:> Nat)): (?T :> Int)
|
|
/// sub_unify(Nat, ?T(:> Int)): (/* OK */)
|
|
/// sub_unify(Nat, Add(?R)): (?R => Nat, Nat.AddO => Nat)
|
|
/// sub_unify([?T; 0], Mutate): (/* OK */)
|
|
/// ```
|
|
pub(crate) fn sub_unify(
|
|
&self,
|
|
maybe_sub: &Type,
|
|
maybe_sup: &Type,
|
|
sub_loc: Option<Location>,
|
|
sup_loc: Option<Location>,
|
|
param_name: Option<&Str>,
|
|
) -> TyCheckResult<()> {
|
|
erg_common::log!(info "trying sub_unify:\nmaybe_sub: {maybe_sub}\nmaybe_sup: {maybe_sup}");
|
|
// In this case, there is no new information to be gained
|
|
// この場合、特に新しく得られる情報はない
|
|
if maybe_sub == &Type::Never || maybe_sup == &Type::Obj || maybe_sup == maybe_sub {
|
|
return Ok(());
|
|
}
|
|
let maybe_sub_is_sub = self.rec_subtype_of(maybe_sub, maybe_sup);
|
|
if maybe_sub.has_no_unbound_var() && maybe_sup.has_no_unbound_var() && maybe_sub_is_sub {
|
|
return Ok(());
|
|
}
|
|
if !maybe_sub_is_sub {
|
|
let loc = sub_loc.or(sup_loc).unwrap_or(Location::Unknown);
|
|
return Err(TyCheckError::type_mismatch_error(
|
|
line!() as usize,
|
|
loc,
|
|
self.caused_by(),
|
|
param_name.unwrap_or(&Str::ever("_")),
|
|
maybe_sup,
|
|
maybe_sub,
|
|
self.get_type_mismatch_hint(maybe_sup, maybe_sub),
|
|
));
|
|
}
|
|
match (maybe_sub, maybe_sup) {
|
|
(Type::FreeVar(lfv), _) if lfv.is_linked() =>
|
|
self.sub_unify(&lfv.crack(), maybe_sup, sub_loc, sup_loc, param_name),
|
|
(_, Type::FreeVar(rfv)) if rfv.is_linked() =>
|
|
self.sub_unify(maybe_sub, &rfv.crack(), sub_loc, sup_loc, param_name),
|
|
// lfv's sup can be shrunk (take min), rfv's sub can be expanded (take union)
|
|
// lfvのsupは縮小可能(minを取る)、rfvのsubは拡大可能(unionを取る)
|
|
// sub_unify(?T[0](:> Never, <: Int), ?U[1](:> Never, <: Nat)): (/* ?U[1] --> ?T[0](:> Never, <: Nat))
|
|
// sub_unify(?T[1](:> Never, <: Nat), ?U[0](:> Never, <: Int)): (/* ?T[1] --> ?U[0](:> Never, <: Nat))
|
|
// sub_unify(?T[0](:> Never, <: Str), ?U[1](:> Never, <: Int)): (?T[0](:> Never, <: Str and Int) --> Error!)
|
|
// sub_unify(?T[0](:> Int, <: Add()), ?U[1](:> Never, <: Mul())): (?T[0](:> Int, <: Add() and Mul()))
|
|
// sub_unify(?T[0](:> Str, <: Obj), ?U[1](:> Int, <: Obj)): (/* ?U[1] --> ?T[0](:> Str or Int) */)
|
|
(Type::FreeVar(lfv), Type::FreeVar(rfv))
|
|
if lfv.constraint_is_sandwiched() && rfv.constraint_is_sandwiched() =>
|
|
{
|
|
let (lsub, lsup) = lfv.get_bound_types().unwrap();
|
|
let l_cyc = lfv.cyclicity();
|
|
let (rsub, rsup) = rfv.get_bound_types().unwrap();
|
|
let r_cyc = rfv.cyclicity();
|
|
let cyclicity = l_cyc.combine(r_cyc);
|
|
let intersec = self.rec_intersection(&lsup, &rsup);
|
|
let new_constraint = if intersec != Type::Never {
|
|
Constraint::new_sandwiched(self.rec_union(&lsub, &rsub), intersec, cyclicity)
|
|
} else {
|
|
return Err(TyCheckError::subtyping_error(
|
|
line!() as usize,
|
|
maybe_sub,
|
|
maybe_sup,
|
|
sub_loc,
|
|
sup_loc,
|
|
self.caused_by(),
|
|
));
|
|
};
|
|
if lfv.level().unwrap() <= rfv.level().unwrap() {
|
|
lfv.update_constraint(new_constraint);
|
|
rfv.link(maybe_sub);
|
|
} else {
|
|
rfv.update_constraint(new_constraint);
|
|
lfv.link(maybe_sup);
|
|
}
|
|
return Ok(())
|
|
}
|
|
(_, Type::FreeVar(rfv)) if rfv.is_unbound() => {
|
|
// NOTE: cannot `borrow_mut` because of cycle reference
|
|
let rfv_ref = unsafe { rfv.as_ptr().as_mut().unwrap() };
|
|
match rfv_ref {
|
|
FreeKind::NamedUnbound { constraint, .. }
|
|
| FreeKind::Unbound { constraint, .. } => match constraint {
|
|
// * sub_unify(Nat, ?E(<: Eq(?E)))
|
|
// sub !<: l => OK (sub will widen)
|
|
// sup !:> l => Error
|
|
// * sub_unify(Str, ?T(:> _, <: Int)): (/* Error */)
|
|
// * sub_unify(Ratio, ?T(:> _, <: Int)): (/* Error */)
|
|
// sub = max(l, sub) if max exists
|
|
// * sub_unify(Nat, ?T(:> Int, <: _)): (/* OK */)
|
|
// * sub_unify(Int, ?T(:> Nat, <: Obj)): (?T(:> Int, <: Obj))
|
|
// * sub_unify(Nat, ?T(:> Never, <: Add(?R))): (?T(:> Nat, <: Add(?R))
|
|
// sub = union(l, sub) if max does not exist
|
|
// * sub_unify(Str, ?T(:> Int, <: Obj)): (?T(:> Str or Int, <: Obj))
|
|
// * sub_unify({0}, ?T(:> {1}, <: Nat)): (?T(:> {0, 1}, <: Nat))
|
|
Constraint::Sandwiched { sub, sup, cyclicity } => {
|
|
let judge = match cyclicity {
|
|
Cyclicity::Super => self.cyclic_supertype_of(rfv, maybe_sub),
|
|
Cyclicity::Not => self.rec_supertype_of(sup, maybe_sub),
|
|
_ => todo!(),
|
|
};
|
|
if !judge {
|
|
return Err(TyCheckError::subtyping_error(
|
|
line!() as usize,
|
|
maybe_sub,
|
|
sup, // TODO: this?
|
|
sub_loc,
|
|
sup_loc,
|
|
self.caused_by(),
|
|
));
|
|
}
|
|
if let Some(new_sub) = self.rec_max(maybe_sub, sub) {
|
|
*constraint =
|
|
Constraint::new_sandwiched(new_sub.clone(), mem::take(sup), *cyclicity);
|
|
} else {
|
|
let new_sub = self.rec_union(maybe_sub, sub);
|
|
*constraint = Constraint::new_sandwiched(new_sub, mem::take(sup), *cyclicity);
|
|
}
|
|
}
|
|
// sub_unify(Nat, ?T(: Type)): (/* ?T(:> Nat) */)
|
|
Constraint::TypeOf(ty) => {
|
|
if self.rec_supertype_of(&Type, ty) {
|
|
*constraint = Constraint::new_supertype_of(maybe_sub.clone(), Cyclicity::Not);
|
|
} else {
|
|
todo!()
|
|
}
|
|
}
|
|
_ => unreachable!(),
|
|
},
|
|
_ => {}
|
|
}
|
|
return Ok(());
|
|
}
|
|
(Type::FreeVar(lfv), _) if lfv.is_unbound() => {
|
|
let lfv_ref = &mut *lfv.borrow_mut();
|
|
match lfv_ref {
|
|
FreeKind::NamedUnbound { constraint, .. }
|
|
| FreeKind::Unbound { constraint, .. } => match constraint {
|
|
// sub !<: r => Error
|
|
// * sub_unify(?T(:> Int, <: _), Nat): (/* Error */)
|
|
// * sub_unify(?T(:> Nat, <: _), Str): (/* Error */)
|
|
// sup !:> r => Error
|
|
// * sub_unify(?T(:> _, <: Str), Int): (/* Error */)
|
|
// * sub_unify(?T(:> _, <: Int), Nat): (/* Error */)
|
|
// sub <: r, sup :> r => sup = min(sup, r) if min exists
|
|
// * sub_unify(?T(:> Never, <: Nat), Int): (/* OK */)
|
|
// * sub_unify(?T(:> Nat, <: Obj), Int): (?T(:> Nat, <: Int))
|
|
// sup = union(sup, r) if min does not exist
|
|
// * sub_unify(?T(:> Never, <: {1}), {0}): (?T(:> Never, <: {0, 1}))
|
|
Constraint::Sandwiched { sub, sup, cyclicity } => {
|
|
if !self.rec_subtype_of(sub, maybe_sup) || !self.rec_supertype_of(sup, maybe_sup) {
|
|
return Err(TyCheckError::subtyping_error(
|
|
line!() as usize,
|
|
sub,
|
|
maybe_sup,
|
|
sub_loc,
|
|
sup_loc,
|
|
self.caused_by(),
|
|
));
|
|
}
|
|
if let Some(new_sup) = self.rec_min(sup, maybe_sup) {
|
|
*constraint =
|
|
Constraint::new_sandwiched(mem::take(sub), new_sup.clone(), *cyclicity);
|
|
} else {
|
|
let new_sup = self.rec_union(sup, maybe_sup);
|
|
*constraint = Constraint::new_sandwiched(mem::take(sub), new_sup, *cyclicity);
|
|
}
|
|
}
|
|
// sub_unify(?T(: Type), Int): (?T(<: Int))
|
|
Constraint::TypeOf(ty) => {
|
|
if self.rec_supertype_of(&Type, ty) {
|
|
*constraint = Constraint::new_subtype_of(maybe_sup.clone(), Cyclicity::Not);
|
|
} else {
|
|
todo!()
|
|
}
|
|
}
|
|
_ => unreachable!(),
|
|
},
|
|
_ => {}
|
|
}
|
|
return Ok(());
|
|
}
|
|
(Type::FreeVar(_fv), _r) => todo!(),
|
|
(Type::Record(lrec), Type::Record(rrec)) => {
|
|
for (k, l) in lrec.iter() {
|
|
if let Some(r) = rrec.get(k) {
|
|
self.sub_unify(l, r, sub_loc, sup_loc, param_name)?;
|
|
} else {
|
|
return Err(TyCheckError::subtyping_error(
|
|
line!() as usize,
|
|
maybe_sub,
|
|
maybe_sup,
|
|
sub_loc,
|
|
sup_loc,
|
|
self.caused_by(),
|
|
));
|
|
}
|
|
}
|
|
return Ok(());
|
|
}
|
|
(Type::Subr(lsub), Type::Subr(rsub)) => {
|
|
for lpt in lsub.default_params.iter() {
|
|
if let Some(rpt) = rsub.default_params.iter().find(|rpt| rpt.name() == lpt.name()) {
|
|
self.unify(lpt.typ(), rpt.typ(), sub_loc, sup_loc)?;
|
|
} else { todo!() }
|
|
}
|
|
lsub.non_default_params.iter().zip(rsub.non_default_params.iter()).try_for_each(
|
|
|(l, r)| self.unify(l.typ(), r.typ(), sub_loc, sup_loc),
|
|
)?;
|
|
self.unify(&lsub.return_t, &rsub.return_t, sub_loc, sup_loc)?;
|
|
return Ok(());
|
|
}
|
|
(_, Type::Ref(t)) => {
|
|
self.unify(maybe_sub, t, sub_loc, sup_loc)?;
|
|
return Ok(());
|
|
}
|
|
(_, Type::RefMut{ before, .. }) => {
|
|
self.unify(maybe_sub, before, sub_loc, sup_loc)?;
|
|
return Ok(());
|
|
}
|
|
(Type::MonoProj { .. }, _) => todo!(),
|
|
(_, Type::MonoProj { .. }) => todo!(),
|
|
(Refinement(_), Refinement(_)) => todo!(),
|
|
_ => todo!("{maybe_sub} can be a subtype of {maybe_sup}, but failed to semi-unify (or existential types are not supported)"),
|
|
}
|
|
}
|
|
}
|