diff options
Diffstat (limited to 'source/slang/slang-check-constraint.cpp')
| -rw-r--r-- | source/slang/slang-check-constraint.cpp | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/source/slang/slang-check-constraint.cpp b/source/slang/slang-check-constraint.cpp index 4d1379016..a03043f31 100644 --- a/source/slang/slang-check-constraint.cpp +++ b/source/slang/slang-check-constraint.cpp @@ -659,6 +659,21 @@ namespace Slang return false; } + bool SemanticsVisitor::TryUnifyConjunctionType( + ConstraintSystem& constraints, + AndType* fst, + Type* snd) + { + // Unifying a type `T` with `A & B` amounts to unifying + // `T` with `A` and also `T` with `B`. + // + // If either unification is impossible, then the full + // case is also impossible. + // + return TryUnifyTypes(constraints, fst->left, snd) + && TryUnifyTypes(constraints, fst->right, snd); + } + bool SemanticsVisitor::TryUnifyTypes( ConstraintSystem& constraints, Type* fst, @@ -674,6 +689,24 @@ namespace Slang if (auto sndErrorType = as<ErrorType>(snd)) return true; + // If one or the other of the types is a conjunction `X & Y`, + // then we want to recurse on both `X` and `Y`. + // + // Note that we check this case *before* we check if one of + // the types is a generic parameter below, so that we should + // never end up trying to match up a type parameter with + // a conjunction directly, and will instead find all of the + // "leaf" types we need to constrain it to. + // + if( auto fstAndType = as<AndType>(fst) ) + { + return TryUnifyConjunctionType(constraints, fstAndType, snd); + } + if( auto sndAndType = as<AndType>(snd) ) + { + return TryUnifyConjunctionType(constraints, sndAndType, fst); + } + // A generic parameter type can unify with anything. // TODO: there actually needs to be some kind of "occurs check" sort // of thing here... |