diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/basicTypes/Var.lhs | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/compiler/basicTypes/Var.lhs b/compiler/basicTypes/Var.lhs index 8e31fef8ea..d7caf2a521 100644 --- a/compiler/basicTypes/Var.lhs +++ b/compiler/basicTypes/Var.lhs @@ -122,14 +122,13 @@ Note [Evidence: EvIds and CoVars] * An EvId (evidence Id) is a *boxed*, term-level evidence variable (dictionary, implicit parameter, or equality). -* DictId, IpId, and EqVar are synonyms when we know what kind of - evidence we are talking about. For example, an EqVar has type (t1 ~ t2). - * A CoVar (coercion variable) is an *unboxed* term-level evidence variable of type (t1 ~# t2). So it's the unboxed version of an EqVar. -* Only CoVars can occur in Coercions (but NB the LCoercion hack; see - Note [LCoercions] in Coercion). +* Only CoVars can occur in Coercions, EqVars appear in TcCoercions. + +* DictId, IpId, and EqVar are synonyms when we know what kind of + evidence we are talking about. For example, an EqVar has type (t1 ~ t2). Note [Kind and type variables] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |