diff options
Diffstat (limited to 'src/unify.cpp')
| -rw-r--r-- | src/unify.cpp | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/src/unify.cpp b/src/unify.cpp index 48818e9..52a3265 100644 --- a/src/unify.cpp +++ b/src/unify.cpp @@ -119,6 +119,13 @@ Constraints::replace(const AType* s, const AType* t) return *this; } +static inline bool +is_dots(const AST* ast) +{ + const AType* type = ast->as_type(); + return (type->kind == AType::NAME && type->head()->str() == "..."); +} + /// Unify a type constraint set (TAPL 22.4) Subst unify(const Constraints& constraints) @@ -143,13 +150,14 @@ unify(const Constraints& constraints) for (; si != s->end() && ti != t->end(); ++si, ++ti) { const AType* st = (*si)->as_type(); const AType* tt = (*ti)->as_type(); - if (st->kind == AType::DOTS || tt->kind == AType::DOTS) + if (is_dots(st) || is_dots(tt)) return unify(cp); else cp.push_back(Constraint(st, tt)); } - if ( (si == s->end() && (ti == t->end() || (*ti)->as_type()->kind == AType::DOTS)) - || (ti == t->end() && (*si)->as_type()->kind == AType::DOTS)) + if ((si == s->end() && ti == t->end()) + || (si != s->end() && is_dots(*si)) + || (ti != t->end() && is_dots(*ti))) return unify(cp); } throw Error(s->loc, |